U.S. patent application number 14/085335 was filed with the patent office on 2014-05-22 for abrasive article comprising abrasive particles of a composite composition.
This patent application is currently assigned to Saint-Gobain Abrasifs. The applicant listed for this patent is Saint-Gobain Abrasifs, Saint-Gobain Abrasives, Inc.. Invention is credited to Anne M. Bonner, Andre Collin, Stefano Francovigh, Muthu Jeevanantham, Lingyu Li, Alejandro Javier Mantecon Torres, Dean S. Matsumoto, Piotr Miziak.
Application Number | 20140137482 14/085335 |
Document ID | / |
Family ID | 50726623 |
Filed Date | 2014-05-22 |
United States Patent
Application |
20140137482 |
Kind Code |
A1 |
Li; Lingyu ; et al. |
May 22, 2014 |
Abrasive Article Comprising Abrasive Particles of a Composite
Composition
Abstract
An abrasive article has a body including an abrasive portion
with a bond material, abrasive particles contained in the bond
material, and a reinforcing member contained in the body. The
abrasive portion can have a fracture propagation toughness WOF of
at least about 5 kJ/m.sup.2. The reinforcing member can have
openings with an open area of not greater than about 100 mm.sup.2
within a major plane of the reinforcing member.
Inventors: |
Li; Lingyu; (Shrewsbury,
MA) ; Jeevanantham; Muthu; (Shrewsbury, MA) ;
Bonner; Anne M.; (Nashua, NH) ; Matsumoto; Dean
S.; (Worcester, MA) ; Miziak; Piotr; (Kolo,
PL) ; Collin; Andre; (Brussels, BE) ; Mantecon
Torres; Alejandro Javier; (Miranda de Ebro, ES) ;
Francovigh; Stefano; (Buttrio, IT) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Saint-Gobain Abrasifs
Saint-Gobain Abrasives, Inc. |
Conflans-Sainte-Honorine
Worcester |
MA |
FR
US |
|
|
Assignee: |
Saint-Gobain Abrasifs
Conflans-Sainte-Honorine
MA
Saint-Gobain Abrasives, Inc.
Worcester
|
Family ID: |
50726623 |
Appl. No.: |
14/085335 |
Filed: |
November 20, 2013 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61728496 |
Nov 20, 2012 |
|
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|
Current U.S.
Class: |
51/309 |
Current CPC
Class: |
B24D 3/34 20130101; B24D
5/04 20130101 |
Class at
Publication: |
51/309 |
International
Class: |
B24D 5/04 20060101
B24D005/04 |
Claims
1. An abrasive article comprising: a body including an abrasive
portion having: a bond material; abrasive particles contained in
the bond material; a reinforcing member contained in the body;
wherein the abrasive portion has a fracture propagation toughness
WOF of at least about 5 kJ/m.sup.2, and the reinforcing member has
openings with an open area of not greater than about 100 mm.sup.2
within a major plane of the reinforcing member.
2. The abrasive article of claim 1, wherein the fracture
propagation toughness WOF is at least about 6 kJ/m.sup.2.
3. The abrasive article of claim 1, wherein the reinforcing member
comprises a greige weight of not greater than about 950 g/m.sup.2,
and not less than about 400 g/m.sup.2.
4. The abrasive cutting tool of claim 1, wherein the reinforcing
member comprises a maximum thickness of at least about 1 mm, and
not greater than about 2 mm.
5. The abrasive article of claim 1, wherein the reinforcing member
comprises threads with the openings therebetween, and the threads
have a width of not less than about 1 mm, and not greater than
about 4 mm.
6. The abrasive cutting tool of claim 1, wherein the open area is
not greater than about 80 mm.sup.2 within the major plane of the
reinforcing member, and at least about 5 mm.sup.2.
7. The abrasive article of claim 1, wherein the reinforcing member
comprises fiber bundles with the openings therebetween, and a
distance from one fiber bundle to an adjacent fiber bundle is at
least about 2 mm, and not greater than about 10 mm.
8. The abrasive cutting tool of claim 1, wherein the openings
extend axially through at least a portion of a thickness of the
reinforcing member.
9. The abrasive cutting tool of claim 1, wherein the reinforcing
member comprises not greater than about 0.5% of an average
thickness of the body, and not greater than about 5%.
10. The abrasive cutting tool of claim 1, wherein a volumetric
ratio of the abrasive portion to the reinforcing member is at least
about 5, and not greater than about 20.
11. The abrasive cutting tool of claim 1, wherein the body has an
adhesion of at least about 1700 lbf.
12. The abrasive article of claim 11, wherein the adhesion of the
body is at least about 1800 lbf, and not greater at least about
2200 lbf.
13. The abrasive cutting tool of claim 1, wherein the body has an
Adhesion Variance Factor (AVF) of not greater than about 10%.
14. The abrasive article of claim 1, wherein the reinforcing member
has a fracture initiation toughness (G.sub.1C) of at least about
3.3 kJ/m.sup.2, and not greater than about 5 kJ/m.sup.2.
15. The abrasive article of claim 1, further comprising a first
filler contained within the abrasive portion comprising iron and
sulfur having an average particle size of not greater than about 40
microns, wherein the first filler comprises pyrite (FeS.sub.2),
wherein the first filler consists essentially of pyrite.
16. The abrasive article of claim 1, wherein the body comprises at
least about 30 vol % bond material for the total volume of the
body, at least about 35 vol %, at least about 40 vol %, at least
about 45 vol %, at least about 50 vol %, at least about 55 vol %,
at least about 60 vol %, at least about 65 vol %, and not greater
than about 70 vol %, not greater than about 65 vol %, not greater
than about 60 vol %, not greater than about 55 vol %, not greater
than about 50 vol %, not greater than about 45 vol %, not greater
than about 40 vol %, not greater than about 35 vol %.
17. The abrasive article of claim 1, wherein the body comprises at
least about 30 vol % abrasive particles for the total volume of the
body, at least about 35 vol %, at least about 40 vol %, at least
about 45 vol %, at least about 50 vol %, at least about 55 vol %,
at least about 60 vol %, at least about 65 vol %, and not greater
than about 70 vol %, not greater than about 65 vol %, not greater
than about 60 vol %, not greater than about 55 vol %, not greater
than about 50 vol %, not greater than about 45 vol %, not greater
than about 40 vol %, not greater than about 35 vol %.
18. An abrasive article comprising: a body including an abrasive
portion having: a bond material; abrasive particles contained in
the bond material; a first filler contained within the abrasive
portion comprising iron and sulfur having an average particle size
of not greater than about 40 microns; and a reinforcing member
contained in the body, the reinforcing member comprising: (a) a
greige weight of not greater than about 950 g/m.sup.2; or (b) a
thickness of not greater than about 2 mm; or (c) fiber bundles with
the openings therebetween, and one fiber bundle and one opening
have a combined dimension of not greater than about 15 mm; or (d)
openings with an open area of not greater than about 100
mm.sup.2.
19. The abrasive article of claim 1, wherein the reinforcing member
comprises a lock leno weave.
Description
[0001] This application claims priority to and the benefit of U.S.
Provisional Pat. App. No. 61/728,496, filed Nov. 20, 2012, and is
incorporated herein by reference in its entirety.
BACKGROUND
[0002] 1. Field of the Disclosure
[0003] The following is directed to abrasive articles, and
particularly, bonded abrasive articles comprising abrasive
particles comprising a composite composition.
[0004] 2. Description of the Related Art
[0005] Abrasive wheels are typically used for cutting, abrading,
and shaping of various materials, such as stone, metal, glass,
plastics, among other materials. Generally, the abrasive wheels can
have various phases of materials including abrasive grains, a
bonding agent, and some porosity. Depending upon the intended
application, the abrasive wheel can have various designs and
configurations. For example, for applications directed to the
grinding of workpieces, some abrasive wheels are fashioned such
that they have a relative thicker profile for efficient
grinding.
[0006] However, given the application of such wheels, the abrasive
articles are subject to fatigue and failure. In fact, the wheels
may have a limited time of use of less than a day depending upon
the frequency of use. Accordingly, the industry continues to demand
abrasive wheels capable of improved performance.
SUMMARY
[0007] Embodiments of an abrasive article can include a body
including an abrasive portion having a bond material, abrasive
particles contained in the bond material, and a reinforcing member
contained in the body. The abrasive portion can have a fracture
propagation toughness WOF of at least about 5 kJ/m.sup.2. The
reinforcing member can have openings with an open area of not
greater than about 100 mm.sup.2 within a major plane of the
reinforcing member.
[0008] In some embodiments, an abrasive article can include a body
including an abrasive portion having a bond material, abrasive
particles contained in the bond material, and a reinforcing member
contained in the body. The body can have an adhesion of at least
about 1700 lbf, and an Adhesion Variance Factor (AVF) of not
greater than about 10%.
[0009] In still other embodiments, an abrasive article can include
a body including an abrasive portion having a bond material,
abrasive particles contained in the bond material, a first filler
contained within the abrasive portion comprising iron and sulfur
having an average particle size of not greater than about 40
microns, and a reinforcing member contained in the body. The
reinforcing member can include a greige weight (or uncoated weight)
of not greater than about 950 g/m.sup.2; and/or a thickness of not
greater than about 2 mm; and/or fiber bundles with the openings
therebetween, and one fiber bundle and one opening have a combined
dimension defined as a unit cell (UC) of not greater than about 15
mm; and/or openings with an open area of not greater than about 100
mm.sup.2.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The present disclosure may be better understood, and its
numerous features and advantages made apparent to those skilled in
the art by referencing the accompanying drawings.
[0011] FIG. 1 includes a schematic side view of an abrasive tool in
accordance with an embodiment.
[0012] FIG. 2 includes a schematic sectional radial view of a
portion of an abrasive tool in accordance with an embodiment.
[0013] FIG. 3 includes a schematic, sectional radial view of a
portion of an abrasive tool in accordance with another
embodiment.
[0014] FIGS. 4A and 4B include plan views of embodiments of a
reinforcing member and, FIG. 4C includes a table of various
dimensions of conventional reinforcing members and embodiments of a
reinforcing member.
[0015] FIG. 5 includes plots of adhesion performance of abrasive
articles in accordance with an embodiment and various conventional
abrasive articles.
DETAILED DESCRIPTION
[0016] The abrasive tools may utilize abrasive portions of abrasive
grains contained within a matrix material for grinding, abrading,
and finishing of workpieces. Certain embodiments herein are
directed to abrasive grinding wheels incorporating one or more
reinforcing members within the body of the tool that are
particularly suited for grinding and/or shaping metal. The abrasive
article can be configured to operate at a speed of at least about
10,000 sfpm, at least about 11,000 sfpm, or even at least about
12,000 sfpm.
[0017] FIG. 1 includes an illustration of an abrasive tool in
accordance with an embodiment. Notably, the abrasive tool 100
includes a body 101 having a generally circular shape as viewed in
two dimensions. It will be appreciated, that in three dimensions
the tool has a certain thickness such that the body 101 has a
disk-like or a cylindrical shape. As illustrated, the body can have
an outer diameter 103 extending through the center of the tool,
which can be particularly large, having a dimension of at least
about 20 cm. In other applications, the body 101 can have an outer
diameter 103, such as on the order of at least about 30 cm, at
least about 40 cm, at least about 50 cm, at least about 60 cm, at
least about 70 cm, at least about 80 cm, or even at least 90 cm.
Embodiments of the outer diameter 103 may be not greater than about
120 cm, such as not greater than about 110 cm, not greater than
about 100 cm, not greater than about 90 cm, or even not greater
than about 80 cm. Particular abrasive tools utilize a body 101
having an outer diameter 103 within a range of any of the previous
minimum and maximum values.
[0018] As further illustrated, the abrasive tool 100 can include a
central opening 105 defined by an inner circular surface 102 about
the center of the body 101. The central opening 105 can extend
through the entire thickness of the body 101 such that the abrasive
tool 100 can be mounted on a spindle or other machine for rotation
of the abrasive tool 100 during operation.
[0019] FIG. 2 includes a sectional illustration of a portion of an
abrasive tool in accordance with an embodiment. The abrasive body
201 can be a composite article including a combination of portions
of different types of material. In particular, the body 201 can
include abrasive portions 204, 206, 208, and 210 and reinforcing
members 205, 207, and 209. The abrasive tool 200 can be designed
such that the reinforcing members 205, 207, and 209 can be placed
within the body such that they are spaced apart from each other,
and therein, separate each of the abrasive portions 204, 206, 208,
and 210 from each other. That is, the abrasive tool 200 can be
formed such that the reinforcing members 205, 207, and 209 are
spaced apart from each other laterally through the thickness 212 of
the body 201 and separated by abrasive portions 206 and 208. As
will be appreciated, in such a design the abrasive portions 206 and
208 can be disposed between the reinforcing members 205, 207, and
209.
[0020] As further illustrated, the reinforcing members 205, 207,
and 209 can be substantially planar members having first planar
faces and second planar faces. For example, the reinforcing member
205 can be formed such that it is a planar member having a first
major surface 215 and a second major surface 216. Moreover, the
body 201 can have a design such that the abrasive portions 204,
206, 208, and 210 can overlie the major surface of the reinforcing
members 205, 207, and 209. For example, the abrasive portion 204
can overlie the first major surface 215 of the reinforcing member
205 and the abrasive portion 206 overlies the second major surface
216 of the reinforcing member 205. In particular instances, the
body 201 can be formed such that the abrasive portions 204 and 206
cover essentially the entire surface area of the first major
surface 215 and second major surface 216, respectively.
Accordingly, the abrasive portions 204 and 206 can directly contact
(i.e. abut) the reinforcing member 205 on either sides at the first
and second major surfaces 215 and 216.
[0021] Notably, the abrasive body 201 can be designed such that the
reinforcing members 205, 207, and 209 can extend through a majority
of the diameter 103 of the body 201. In particular instances, the
reinforcing members 205, 207, and 209 can be formed such that they
extend through at least about 75%, such as at least about 80%, or
even the entire diameter 103 of the body 201.
[0022] As shown in the embodiment of FIG. 3, the reinforcing
members 303, 305 may vary in length and position throughout an
abrasive body 301. For example, the abrasive body 301 may comprise
one or more relatively shorter reinforcing members 303 (e.g., six
shown), as well as one or more relatively longer reinforcing
members 305 (e.g., four shown). Embodiments of members 303 may
extend only through an outer section 311 of the abrasive body 301,
but not an inner section 313. Embodiments of members 305 may extend
through the entire diameter of the abrasive body 301, such as outer
section 311 and inner section 313. These reinforcing members 303,
305 also may be arranged axially with respect to central axis 350
in a variety of patterns. For example, as depicted in FIG. 3, two
members 303 may be located between adjacent members 305. Metallic
reinforcement rings 355 also may be provided in inner section
313.
[0023] As stated herein, the number of reinforcing members may vary
depending on the application. For example, the abrasive body may
have 1 to 15 reinforcing members in some embodiments. In other
embodiments, the abrasive body may have at least 2 reinforcing
members, such as at least 4 reinforcing members, at least 6
reinforcing members, at least 8 reinforcing members, or even at
least 10 reinforcing members. In other examples, the abrasive body
may have not greater than 14 reinforcing members, such as not
greater than 12 reinforcing members, not greater than 10
reinforcing members, or even not greater than 8 reinforcing
members. The number of reinforcing members may be in a range
between any of the foregoing values.
[0024] In accordance with the embodiment of FIG. 2, the body 201
may be formed such that it can have an average thickness 212
measured in a direction parallel to the axis 250 extending through
the center of the central opening 105. The average thickness 212 of
the body 201 can be at least about 3 cm, such as at least about 5
cm, at least about 7 cm, at least about 9 cm, or even at least
about 11 cm. In other embodiments, the average thickness 212 can be
not greater than about 18 cm, such as not greater than about 16 cm,
not greater than about 14 cm, not greater than about 12 cm, or even
not greater than about 10 cm. Still, certain embodiments may
utilize an average thickness 212 within a range between any of the
minimum and maximum values described above.
[0025] The disk also may have an aspect ratio defined as an outer
diameter OD to axial thickness AT (OD:AT) of at least about 2, such
as at least about 5, at least about 7, at least about 10, or even
at least about 20. In other embodiments, the aspect ratio may be
not greater than about 40, such as not greater than about 30, not
greater than about 20, not greater than about 15, or even not
greater than about 10. Certain embodiments may utilize an aspect
ratio within a range between any of the minimum and maximum values
given above.
[0026] In further reference to the reinforcing members 205, 207,
and 209, such members can be made of an organic material, inorganic
material, and a combination thereof. For example, the reinforcing
members 205, 207, and 209 can be made of an inorganic material,
such as a ceramic, a glass, quartz, or a combination thereof.
Particularly suitable materials for use as the reinforcing members
205, 207, and 209 can include glass materials, incorporating fibers
of glass materials, which may include oxide-based glass
materials.
[0027] Some suitable organic materials for use in the reinforcing
members 205, 207, and 209 can include phenolic resin, polyimides,
polyamides, polyesters, aramids, and a combination thereof. For
example, in one particular embodiment, the reinforcing members 205,
207, and 209 can include Kevlar.TM., a particular type of aramid.
Moreover, embodiments of the reinforcing member may comprise a
phenolic resin-based binder.
[0028] The reinforcing members 205, 207, and 209 can include a
plurality of fibers that are woven together. The fibers can be
woven or stitched together in a variety of manners. In certain
instances, the reinforcing members can be woven together such that
a pattern is formed, including fibers extending primarily in two
perpendicular directions.
[0029] The reinforcing members 205, 207, and 209 can have a maximum
thickness 218 that is defined as the distance between the first
major surface 215 and the second major surface 216 of the
reinforcing member 205. The maximum thickness 218 of each
reinforcing member can be at least about 1 mm, such as at least
about 1.1 mm, at least about 1.2 mm, or even at least about 1.3 mm.
In other embodiments, the maximum thickness 218 can be not greater
than about 2 mm, such as not greater than about 1.8 mm, not greater
than about 1.5 mm, or even not greater than about 1.4 mm. Certain
embodiments may utilize a thickness within a range between any of
the minimum and maximum values given above.
[0030] In relative percentages, depending upon the design of the
abrasive article, the reinforcing members can be formed to have
certain dimensions such that they compose a certain percentage of
the total average thickness of the body. For example, the
reinforcing members can be at least about 3 vol % of the total
volume of the body 201. In other instances, the reinforcing member
205 can be at least about 5 vol %, such as at least about 7 vol %,
or even at least about 9 vol % of the total volume of the body 201.
In still other embodiments, the reinforcing members can be not
greater than about 17 vol % of the total volume of the body, such
as not greater than about 15 vol %. Certain embodiments of the
abrasive article can have reinforcing members within a range
between the minimum and maximum values given above.
[0031] In some embodiments, a volumetric ratio of the abrasive
portion to the reinforcing members is at least about 5, such as at
least about 10, or even at least about 15. Other embodiments have a
volumetric ratio of not greater than about 20, such as not greater
than about 15, or even not greater than about 10. Certain
embodiments of the abrasive article can have reinforcing members
within a range between the minimum and maximum values given
above.
[0032] In accordance with embodiments herein, the abrasive tool 200
is formed such that the body 201 includes abrasive portions 204,
206, 208, and 210. Reference will be made in the following
paragraphs to the abrasive portion 204, however it will be
appreciated that all of the identified abrasive portions can
include the same features. The abrasive portion 204 can be a
composite material having abrasive grains contained within a matrix
material and further comprising a particular composition and type
of porosity.
[0033] The abrasive grains can include a particularly hard material
suitable for abrading and material removal applications. For
example, the abrasive grains can have a Vickers hardness of at
least about 5 GPa. The hardness of the abrasive grains can be
greater in some tools, such that the abrasive grains have a Vickers
hardness of at least about 10 GPa, at least about 20 GPa, at least
about 30 GPa, or even at least about 50 GPa.
[0034] As further illustrated in FIG. 2, the body can be formed
such that it incorporates reinforcing members 202 and 203 that abut
the outer surfaces of the abrasive portions 204 and 210 about the
central opening 105. In certain designs, the reinforcing members
202 and 203 can extend for a portion of the outer diameter 103,
such as half the outer diameter 103 of the abrasive body 201.
Provision of the reinforcing members 202 and 203 about the central
opening 105 facilitates reinforcement of the body 201 at a location
where the abrasive tool 200 is intended to be affixed to a spindle
or machine. As will be appreciated, the reinforcing members 202 and
203 can have the same features as the reinforcing members 205, 207,
and 209.
[0035] Embodiments of the body of the abrasive article may comprise
a reinforcing member, such as a first reinforcing member. The first
reinforcing member may abut the abrasive portion. The first
reinforcing member may be disposed within the abrasive portion.
Alternatively, the first reinforcing member may define an external
surface of the body. In addition, the first reinforcing member may
be disposed internally within the body.
[0036] Some embodiments of the first reinforcing member may
comprise an organic material. In particular embodiments, the first
reinforcing member may comprise a polyimide, polyamide, polyester,
aramid, and a combination thereof. Alternatively, the first
reinforcing member may comprise an inorganic material. For example,
the inorganic material may comprise ceramic materials, glass
materials, glass-ceramic materials, or a combination thereof.
Alternatively, the first reinforcing member may comprise glass
fibers
[0037] In still other versions, the first reinforcing member may
extend through an entire diameter of the body. The first
reinforcing member may comprise a planar member comprising a first
major surface and a second major surface. The abrasive portion may
overlie the first major surface. Alternatively, the abrasive
portion can be in direct contact with the first major surface of
the first reinforcing member.
[0038] Alternate embodiments of the body of the abrasive article
may comprise a first reinforcing member and a second reinforcing
member. The first reinforcing member and the second reinforcing
member can be spaced apart from each other within the body.
Alternatively, at least a portion of the abrasive portion may be
disposed between the first reinforcing member and the second
reinforcing member.
[0039] In a particular embodiment of the abrasive article, the
first reinforcing member can be at least about 0.5% of an average
thickness of the body. For example, the first reinforcing member
can be at least about 1% of the average thickness of the body, such
as at least about 1.1%, or even at least about 1.2%. In other
non-limiting embodiments, the first reinforcing member can be not
greater than about 5% of the average thickness of the body, such as
not greater than about 2%, or even not greater than about 1.5%. The
average thickness of the body can have a first reinforcing member
content within a range between any of the minimum and maximum
values noted above.
[0040] The abrasive article can be formed by forming a mixture of
components or precursor components that may be part of the final
abrasive article. In one embodiment, the mixture can include
abrasive particles. In a particular instance, the abrasive
particles can have composite composition including alumina
(Al.sub.2O.sub.3), iron oxide (Fe.sub.2O.sub.3), silica
(SiO.sub.2), calcia (CaO), titania (TiO.sub.2) and the like. In
certain circumstances, the composite composition can include a
majority content of alumina. For example, the composite composition
can have at least about 82% alumina for the total content of
compounds (or elements) within the composite composition. In other
instances, the content of alumina can be greater, such as at least
about 83%, at least about 84%, at least about 85%, at least about
86%, or even at least about 87%, at least about 88%. Still, in at
least one non-limiting embodiment, the composite composition can
contain not greater than about 95% alumina, such as not greater
than about 92% alumina, not greater than about 91% alumina, not
greater than about 90% alumina, or even not greater than about 89%
alumina. It will be appreciated that the composite composition can
have a content of alumina within a range between any of the above
noted minimum and maximum percentages.
[0041] According to one embodiment, the composite composition can
have a minority content of silica. For example, in one instance,
the composite composition can have a lesser content of silica as
compared to the content of alumina. In a particular embodiment, the
composite composition can have not greater than about 6.6% silica,
such as not greater than about 6.5% silica, not greater than about
6% silica, not greater than about 5% silica, not greater than about
4% silica, or even not greater than about 3% silica. Still, in at
least one non-limiting embodiment, the composite composition can
have at least about 1% silica, such as at least about 2% silica, or
even at least about 3% silica. It will be appreciated that the
composite composition can have a content of silica within a range
between any of the above noted minimum and maximum percentages.
[0042] In accordance with another embodiment, the composite
composition can include a minority content of iron oxide. For
example, the composite composition may include a lesser content of
iron oxide as compared to the content of alumina. Furthermore, in
other instances, the composite composition may have a lesser
content of iron oxide as compared to the content of silica. Still,
in another alternative embodiment, the composite composition can
have a greater content of iron oxide as compared to the content of
silica. For one particular embodiment, the composite composition of
the abrasive particles can have not greater than about 7% iron
oxide, such as not greater than about 6% iron oxide, not greater
than about 5% iron oxide, not greater than about 4.5% iron oxide,
or even not greater than about 4% iron oxide. Still, in other
non-limiting examples, the composite composition may have at least
about 1% iron oxide, such as at least about 2% iron oxide, or even
at least about 3% iron oxide. It will be appreciated that the
composite composition can have a content of silica within a range
between any of the above noted minimum and maximum percentages.
[0043] Certain exemplary composite compositions of the abrasive
particles may further include some content of titania (TiO.sub.2).
For example, one composite composition may include a minority
content of titania. In other particular instances, the composite
composition can have a lesser content of titania as compared to the
content of alumina. In yet another embodiment, the composite
composition can have a lesser content of titania as compared to the
content of silica. And yet in another embodiment, the composite
composition may have a lesser content of titania as compared to the
content of iron oxide. For at least one non-limiting embodiment,
the composite composition can have not greater than about 5%
titania, such as not greater than about 4% titania. Still, for one
non-limiting embodiment, the composite composition can include at
least about 3.8% titania, such as at least about 3.9% titania. It
will be appreciated that the composite composition can have a
content of titania within a range between any of the above noted
minimum and maximum percentages.
[0044] The composite composition may, in certain instances, include
a content of calcia (CaO). For example, the composite composition
may include a minority content of calcia. More specifically, in one
particular embodiment, the composite composition can have a lesser
content of calcia as compared to the content of alumina. Moreover,
certain composite compositions can have a lesser content of calcia
as compared to the content of silica. In yet another embodiment,
the composite composition can include a lesser content of calcia as
compared to the content of iron oxide. For one particular composite
composition, the content of calcia can be less than the content of
titania. According to one particular embodiment, the composite
composition can have not greater than about 5% calcia, such as not
greater than about 4% calcia, not greater than about 3% calcia, not
greater than about 2% calcia, or even not greater than about 1%
calcia. In at least one non-limiting embodiment, the composite
composition can have at least about 0.3% calcia, such as at least
about 0.4% calcia, at least about 0.5% calcia, at least about 0.6%
calcia, or even at least about 0.7% calcia, at least about 0.8%
calcia. It will be appreciated that the composite composition can
have a content of calcia within a range between any of the above
noted minimum and maximum percentages.
[0045] Certain composite compositions of the abrasive particles may
also include some content of magnesia (MgO). According to one
embodiment, the composite composition can include a minority
content of magnesia. In particular instances, the composite
composition can have a lesser content of magnesia as compared to
the content of alumina. For another embodiment, the composite
composition may have a lesser content of magnesia as compared to
the content of silica. In accordance with another embodiment, the
composite composition may have a lesser content of magnesia as
compared to the content of iron oxide. In certain other instances,
the composite composition may have a lesser content of magnesia as
compared to the content of titania. Furthermore, the composite
composition may have a lesser content of magnesia as compared to
the content of calcia. Still, in at least one non-limiting
embodiment, the composite composition can have a greater content of
magnesia as compared to a content of calcia. According to one
particular embodiment, the composite composition may have not
greater than about 40% magnesia, such as not greater than about 30%
magnesia, not greater than about 20% magnesia, not greater than
about 15% magnesia, not greater than about 10% magnesia, not
greater than about 8% magnesia, not greater than about 5% magnesia,
or even not greater than about 2% magnesia. Still, in at least one
non-limiting embodiment, the composite composition may include at
least about 0.05% magnesia, such as at least about 0.1% magnesia.
It will be appreciated that the composite composition can have a
content of magnesia within a range between any of the above noted
minimum and maximum percentages.
[0046] According to one embodiment, the composite composition can
include a combination of alumina, silica, iron oxide, magnesia,
calcia, and titania. In one aspect, the composition can be an ore,
which has been mined and generally unrefined. According to one
embodiment, the abrasive particles can be made of a crystalline
material, and more particularly, can consist essentially of a
crystalline material. In one particular embodiment, the composite
composition can be bauxite, and more particularly, the abrasive
particles may consist essentially of bauxite.
[0047] The abrasive particles may have other particular features.
For example, the abrasive particles may have an elongated shaped.
In particular instances, the abrasive particles may have an aspect
ratio, defined as a ratio of the length:width of at least about
1:1, wherein the length is the longest dimension of the particle
and the width is the second longest dimension of the particle (or
diameter) perpendicular to the dimension of the length. In other
embodiments, the aspect ratio of the abrasive particles can be at
least about 2:1, such as at least about 2.5:1, at least about 3:1,
at least about 4:1, at least about 5:1, or even at least about
10:1. In one non-limiting embodiment, the abrasive particles may
have an aspect ratio of not greater than about 5000:1.
[0048] In at least one embodiment, the abrasive particles can be
extruded, such that the composite composition is extruded and
segmented to make abrasive particles of a desired size and shape.
The abrasive particles may be sintered, and may be sintered in a
particular manner to ensure certain properties and compositions
described in the embodiments herein. According to one embodiment,
the abrasive particles can be formed to have an ellipsoidal
cross-sectional shape. An ellipsoidal shape can include circles,
ellipses, and any other curvilinear shapes. Alternatively, in other
instances, the abrasive particles can have a polygonal
cross-sectional shape. Some suitable, non-limiting, examples of
polygonal cross-sectional shapes include triangular, rectangular,
pentagonal, hexagonal, septagonal, octagonal, and the like.
[0049] Embodiments of the abrasive particles may be characterized
in terms of grain toughness (K1C) and hardness. For example, the
hardness of the abrasive particles may be less than about 12 GPa.
In some embodiments, the hardness of the abrasive particles may be
less than about 11.5 GPa, such as less than about 11 GPa, less than
about 10.5 GPa, less than about 10 GPa, or even less than about 9.5
GPa. In other embodiments, the hardness of the abrasive particles
may be at least about 8.75 GPa, such as at least about 9 GPa, at
least about 9.5 GPa, at least about 10 GPa, at least about 10.5
GPa, or even at least about 11 GPa. It will be appreciated that the
abrasive particles can have a hardness within a range between any
of the above noted minimum and maximum values.
[0050] Embodiments of the abrasive particles also can have a
toughness of at least about 4.6 MPa-m.sup.0.5. For example, the
abrasive particles may have a toughness of at least about 4.7
MPa-m.sup.0.5, such as at least about 4.8 MPa-m.sup.0.5, at least
about 4.9 MPa-m.sup.0.5, or even at least about 5 MPa-m.sup.0.5. In
still other versions, the abrasive particles can have a toughness
of not greater than about 5.4 MPa-m.sup.0.5, such as not greater
than about 5.3 MPa-m.sup.0.5, not greater than about 5.2
MPa-m.sup.0.5, not greater than about 5.1 MPa-m.sup.0.5, or even
not greater than about 5 MPa-m.sup.0.5. It will be appreciated that
the abrasive particles can have a toughness within a range between
any of the above noted minimum and maximum values.
[0051] Regarding absolute values for single grain crush strength,
the force (in newtons) required to break the grains may be given in
terms of the percentage of the grains broken when subjected to
breaking force. For example, in one embodiment, about 500 N to
about 800 N may be required to break 50% of one or more types of
the abrasive particles. In one embodiment, to break 50% of the
abrasive particles, at least about 500 N, such as at least about
600 N, or even at least about 700 N is required. In another
non-limiting embodiment no greater than about 1000 N is required to
break the abrasive particles, such as no greater than about 900 N,
or even no greater than about 800 N is required. It will be
appreciated that each type of abrasive particle can have an
absolute crush strength within a range between the above noted
minimum and maximum values.
[0052] In another embodiment, in order to break 90% of each type of
abrasive particle about 850 N to about 1350 N of force may be
required. In one embodiment, to break 50% of the abrasive
particles, at least about 800 N, such as at least about 850 N, or
even at least about 900 N is required. In another non-limiting
embodiment no greater than about 1500 N is required to break the
abrasive particles, such as no greater than about 1400 N, or even
no greater than about 1300 N is required. It will be appreciated
that each type of abrasive particle can have an absolute crush
strength within a range between the above noted minimum and maximum
values.
[0053] According to one particular embodiment, the abrasive
particles can have an average particle size of at least about 20
microns, such as at least about 50 microns, at least about 80
microns, at least about 100 microns, at least about 150 microns, at
least about 200 microns, at least about 300 microns, at least about
400 microns, at least about 500 microns, at least about 600
microns, at least about 800 microns, at least about 1000 microns,
at least about 1200 microns, at least about 1500 microns, at least
about 1600 microns, at least about 1700 microns, or even at least
about 1800 microns. Still, in another non-limiting embodiment, the
abrasive particles can have an average particle size of not greater
than about 10 mm, such as not greater than about 5 mm, not greater
than about 4 mm, not greater than about 3 mm, not greater than
about 2 mm, or even not greater than about 1 mm. It will be
appreciated, that the average particle size may be determined by
measuring and averaging the longest dimension (i.e., the length) of
the particles. The abrasive particles can have an average particle
size within a range between any of the minimum and maximum values
noted above.
[0054] According to one embodiment, the abrasive particles can have
a particular porosity, which may facilitate improved performance.
For example, the average porosity of the abrasive particles can be
at least about 0 vol % for the total volume of an abrasive
particle. In one embodiment, the average porosity of the abrasive
particles can be at least about 2 vol %, such as at least about 2.5
vol %, at least about 3 vol %, at least about 3.5 vol %, at least
about 4 vol %, at least about 5 vol %, at least about 7 vol %, at
least about 9 vol %, at least about 11 vol, or even at least about
13 vol %. Still, in one non-limiting embodiment, the average
porosity of the abrasive particles may be not greater than about 15
vol %, such as not greater than about 14 vol %, not greater than
about 12 vol %, not greater than about 10 vol %, not greater than
about 8 vol %, not greater than about 6 vol %, not greater than
about 4 vol %, not greater than about 2 vol %, or even not greater
than about 1 vol % for the total volume of the abrasive particle.
It will be appreciated that the average porosity of the abrasive
particles can be within a range between any of the minimum and
maximum percentages noted above.
[0055] Furthermore, the abrasive particles may have a particular
average pore size. For example, the average pore size of the
abrasive particles can be not greater than about 6 microns, such as
not greater than about 5 microns, not greater than about 4 microns,
not greater than about 3 microns, not greater than about 2 microns,
or even not greater than about 1.5 microns. According to another
non-limiting embodiment, the average pore size of the abrasive
particles can be at least about 0.01 microns, such as at least
about 0.1 microns. It will be appreciated that the average pore
size of the abrasive particles can be within a range between any of
the minimum and maximum percentages noted above.
[0056] The abrasive particles can be made of crystalline grains In
particular instances, the abrasive particles can include
crystalline grains having a median grain size of not greater than
about 1.2 microns. In other instances, the median grain size can be
not greater than about 1 micron, such as not greater than about 0.9
microns, not greater than about 0.8 microns, or even not greater
than about 0.7 microns. According to one non-limiting embodiment,
the median grain size of the abrasive particles can be at least
about 0.01 microns, such as at least about 0.05 microns, at least
about 0.1 microns, at least about 0.2 microns, or even at least
about 0.4 microns. It will be appreciated that the median grain
size of the abrasive particles can be within a range between any of
the minimum and maximum percentages noted above.
[0057] Crystalline grain size was measured from SEM micrographs.
Grains are embedded in epoxy blocks and then polished to obtain a
flat cross-section. The cross-sections are then etched by HF acid
for two minutes to reveal the fine microstructure and measure the
median grain size.
[0058] As described herein, in addition to the abrasive particles,
the mixture may also include other components or precursors to
facilitate formation of the abrasive article. For example, the
mixture may include abrasive particles and a bond material.
According to one embodiment, the bond material may include a
material selected from the group consisting of an organic material,
an organic precursor material, an inorganic material, an inorganic
precursor material, a natural material, and a combination thereof.
In particular instances, the bond material may include a metal or
metal alloy, such as a powder metal material, or a precursor to a
metal material, suitable for formation of a metal bond matrix
material during further processing.
[0059] According to another embodiment, the mixture may include a
vitreous material, or a precursor of a vitreous material, suitable
for formation of a vitreous bond material during further
processing. For example, the mixture may include a vitreous
material in the form of a powder, including for example, an
oxygen-containing material, an oxide compound or complex, a frit,
and any combination thereof.
[0060] In yet another embodiment, the mixture may include a ceramic
material, or a precursor of a ceramic material, suitable for
formation of a ceramic bond material during further processing. For
example, the mixture may include a ceramic material in the form of
a powder, including for example, an oxygen-containing material, an
oxide compound or complex, and any combination thereof.
[0061] According to another embodiment, the mixture may include an
organic material, or a precursor of an organic material, suitable
for formation of an organic bond material during further
processing. Such an organic material may include one or more
natural organic materials, synthetic organic materials, and a
combination thereof. In particular instances, the organic material
can be made of a resin, which may include a thermoset, a
thermoplastic, and a combination thereof. For example, some
suitable resins can include phenolics, epoxies, polyesters, cyanate
esters, shellacs, polyurethanes, rubber, and a combination thereof.
In one particular embodiment, the mixture includes an uncured resin
material configured to form a phenolic resin bond material through
further processing.
[0062] In some embodiments, the resin may have a high temperature
flexure modulus of at least 1.05. Alternatively, the resin may have
an increasing high temperature flexural modulus. The phenolic resin
may be modified with a curing or cross-linking agent, such as
hexamethylene tetramine. At temperatures in excess of about
90.degree. C., some examples of the hexamethylene tetramine may
form crosslinks to form methylene and dimethylene amino bridges
that help cure the resin. The hexamethylene tetramine may be
uniformly dispersed within the resin. More particularly,
hexamethylene tetramine may be uniformly dispersed within resin
regions as a cross-linking agent. Even more particularly, the
phenolic resin may contain resin regions with cross-linked domains
having a sub-micron average size.
[0063] Other materials, such as a filler, can be included in the
mixture. The filler may or may not be present in the finally-formed
abrasive article. The filler may include a material selected from
the group consisting of powders, granules, spheres, fibers, chopped
strand fibers (CSF) and a combination thereof, wherein the filler
comprises a material selected from the group consisting of an
inorganic material, an organic material, and a combination thereof,
wherein the filler comprises a material selected from the group
consisting of sand, bubble alumina, chromites, magnesite,
dolomites, bubble mullite, borides, titanium dioxide, carbon
products, silicon carbide, wood flour, clay, talc, hexagonal boron
nitride, molybdenum disulfide, feldspar, nepheline syenite, glass
spheres, glass fibers, CaF.sub.2, KBF.sub.4, Cryolite
(Na.sub.3AlF.sub.6), potassium Cryolite (K.sub.3AlF.sub.6), pyrite,
ZnS, copper sulfide, mineral oil, fluorides, carbonates, calcium
carbonate, saran, phenoxy resin, CaO, K.sub.2SO.sub.4, mineral
wool, MnCl.sub.2, KCl, and a combination thereof, wherein the
filler comprises a material selected from the group consisting of
an antistatic agent, a lubricant, a porosity inducer, coloring
agent, and a combination thereof. The filler may comprise iron and
sulfur having an average particle size of not greater than about 40
microns. The filler may comprise pyrite (FeS.sub.2), or consist
essentially of pyrite. The filler may comprise a material selected
from the group consisting of an antistatic agent, a lubricant, a
porosity inducer, coloring agent, and a combination thereof. In
particular instances the filler can be particulate material, it may
be distinct from the abrasive particles, being significantly
smaller in average particle size than the abrasive particles.
[0064] After forming the mixture the process of forming the
abrasive article can further include forming a green body
comprising abrasive particles contained in a bond material. A green
body is a body that is unfinished and may undergo further
processing before a finally-formed abrasive article is formed. For
example, forming of the green body can include techniques such as
pressing, hot pressing, molding, casting, printing, spraying, and a
combination thereof. In one particular embodiment, forming of the
green body can include pressing the mixture into a particular
shape.
[0065] After forming the green body, the process can continue by
treating the green body to form a finally-formed abrasive article
comprising a body. Some suitable examples of treating can include
curing, heating, sintering, crystallizing, polymerization,
pressing, and a combination thereof. In one example, the process
may include bond batching, mixing abrasive with bond, filling a
mold, pressing, wheel baking or curing, finishing, inspection,
speed testing, and packing and shipping.
[0066] After treating the abrasive article is formed to have a body
including a particular content of bond material. For example, the
body can have at least about 30 vol % bond material for the total
volume of the body. In other instances, the content of bond
material in the body can be greater, such as at least about 35 vol
%, at least about 40 vol %, at least about 45 vol %, at least about
50 vol %, at least about 55 vol %, at least about 60 vol %, or even
at least about 65 vol %. Still, in at least one non-limiting
embodiment, the content of bond material in the body can be not
greater than about 70 vol %, such as not greater than about 65 vol
%, not greater than about 60 vol %, not greater than about 55 vol
%, not greater than about 50 vol %, not greater than about 45 vol
%, not greater than about 40 vol %, or even not greater than about
35 vol %. It will be appreciated that the content of bond material
in the body can be within a range between any of the minimum and
maximum percentages noted above.
[0067] According to a particular embodiment, the body can have a
particular content of porosity. For example, the body can have not
greater than about 40 vol % porosity for the total volume of the
body. In a particular instance, the body can have not greater than
about 35 vol %, such as not greater than about 30 vol %, not
greater than about 25 vol %, not greater than about 20 vol %, not
greater than about 15 vol %, not greater than about 10 vol %
porosity for the total volume of the body, not greater than about 5
vol %, not greater than about 4 vol %, not greater than about 3 vol
%, not greater than about 2 vol %, not greater than about 1.5 vol
%, not greater than about 1 vol %, not greater than about 0.8 vol
%, not greater than about 0.5 vol %, not greater than about 0.3 vol
%, or even not greater than about 0.1 vol %. The body also can have
at least about 0.001 vol % porosity, such as at least about 0.01
vol % porosity. It will be appreciated that the porosity of the
body can be within a range between any of the minimum and maximum
percentages noted above.
[0068] For certain abrasive articles of the embodiments herein, the
body can have a particular content of abrasive particles. For
example, in one embodiment, the body can include at least about 30
vol % abrasive particles for the total volume of the body. In
another embodiment, the body can have at least about 35 vol %, at
least about 40 vol %, at least about 45 vol %, at least about 50
vol %, at least about 55 vol %, at least about 60 vol %, or even at
least about 65 vol % abrasive particles. In at least one
non-limiting embodiment, the body can have a content of abrasive
particles of not greater than about 70 vol %, such as not greater
than about 65 vol %, not greater than about 60 vol %, not greater
than about 55 vol %, not greater than about 50 vol %, not greater
than about 45 vol %, not greater than about 40 vol %, or even not
greater than about 35 vol %. It will be appreciated that the
content of abrasive particles in the body can be within a range
between any of the minimum and maximum percentages noted above.
[0069] The abrasive articles of the embodiments herein can have a
body that may be in the form of a bonded abrasive having a shape
such as a hone, a cone, a cup, flanged shapes, a cylinder, a wheel,
a ring, and a combination thereof. In one particular embodiment,
the body can be a bonded abrasive snagging wheel.
[0070] According to one embodiment, the abrasive article may be
particularly suited for grinding and conditioning of workpieces.
Certain suitable workpieces can include inorganic materials, and
more particularly workpieces made of a metal or metal alloy.
According to one embodiment, the abrasive article may be
particularly suited to grind materials such as stainless steel or
titanium.
[0071] Embodiments of the abrasive portion can have a fracture
propagation toughness or work of fracture (WOF) of at least about 5
kJ/m.sup.2. The fracture propagation toughness WOF also can be at
least about 6 kJ/m.sup.2, at least about 7 kJ/m.sup.2, at least
about 8 kJ/m.sup.2, at least about 9 kJ/m.sup.2, or even at least
about 10 kJ/m.sup.2. In still other versions, fracture propagation
toughness WOF can be not greater than about 13 kJ/m.sup.2, not
greater than about 12 kJ/m.sup.2, not greater than about 11
kJ/m.sup.2, or even not greater than about 10 kJ/m.sup.2. It will
be appreciated that the abrasive portion can have a fracture
propagation toughness WOF within a range between any of the minimum
and maximum values noted above.
[0072] Embodiments of the reinforcing member can have openings with
an open area of not greater than about 100 mm.sup.2 within a major
plane of the reinforcing member. In other embodiments the open area
can be not greater than about 80 mm.sup.2 within the major plane of
the reinforcing member, not greater than about 60 mm.sup.2, not
greater than about 40 mm.sup.2, not greater than about 35 mm.sup.2,
or even not greater than about 30 mm.sup.2. The open area also can
be at least about 5 mm.sup.2, at least about 8 mm.sup.2, at least
about 10 mm.sup.2, or even at least about 12 mm.sup.2. It will be
appreciated that the open area can be within a range between any of
the minimum and maximum values noted above.
[0073] Embodiments of the openings may extend axially through at
least a portion of a thickness thereof. The openings may extend
entirely through the thickness of the reinforcing member. The
openings also may have perimeters and define polygonal
two-dimensional shapes.
[0074] Still other embodiments of the reinforcing member can have a
greige weight (or uncoated weight) of not greater than about 950
g/m.sup.2. For example, the greige weight can be not greater than
about 800 g/m.sup.2, not greater than about 600 g/m.sup.2, or even
not greater than about 500 g/m.sup.2. Alternatively, the greige
weight can be not less than about 400 g/m.sup.2, not less than
about 450 g/m.sup.2, or even not less than about 490 g/m.sup.2. The
greige weight also can be within a range between any of the minimum
and maximum values noted above.
[0075] In addition, and as depicted in FIGS. 4A and 4B, the
reinforcing member may comprise fiber bundles with the openings
therebetween. The various dimensions (FIG. 4C) of the reinforcing
member depend on many factors, such as the yarns, the thickness of
the coating, and the style of weave. For example, some embodiments
of the reinforcing member may have a selected number of threads per
set distance. In the warp and weft directions, the selected number
of threads may be about 10 to about 15 threads per 100 mm, in some
embodiments, in either or both of the warp and weft directions. The
theoretical distance between the centers of the threads or "s" (in
both the warp and weft directions) may be about 5 mm to about 17
mm, in some embodiments. Examples of the grid dimension or "h"
(i.e., the distance between two threads) may be about 2 mm to about
9 mm. The grid dimension also may be not greater than about 8 mm,
such as not greater than about 6 mm, or even not greater than about
5 mm. The grid dimension also can at least about 2 mm, at least
about 2.5 mm, or even at least about 3 mm. Each of the construction
parameters can be within a range between any of the approximate
minimum and maximum values noted above.
[0076] In some embodiments, the thickness of the thread "y" may be
about 2 mm to about 4 mm in the weft direction, and about 1 mm to
about 3 mm in the warp direction. The thread thickness also may be
not greater than about 6 mm, such as not greater than about 5 mm,
or even not greater than about 4 mm. Again, each of the
construction parameters can be within a range between any of the
approximate minimum and maximum values noted above.
[0077] Some embodiments of the threads can have a width "y" of not
less than about 1 mm, such as not less than about 1.2 mm, not less
than about 1.4 mm, not less than about 1.6 mm, not less than about
1.8 mm, not less than about 2 mm, not less than about 2.2 mm, not
less than about 2.4 mm, not less than about 2.6 mm, or even not
less than about 2.8 mm. In other embodiments, the width of the
fiber bundles can be not greater than about 4.5 mm, such as not
greater than about 4 mm, not greater than about 3.5 mm, not greater
than about 3 mm, not greater than about 2.5 mm, or even not greater
than about 2 mm. The construction also can be within a range
between any of the minimum and maximum values noted above.
[0078] Embodiments of the reinforcing member may comprise a grid
distance "h" from one fiber bundle to an adjacent fiber bundle that
is at least about 2 mm, such as at least about 2.5 mm, at least
about 3 mm, at least about 3.5 mm, at least about 4 mm, at least
about 4.2 mm, at least about 4.4 mm, or even at least about 4.4 mm.
In other embodiments, the distance between fiber bundles is not
greater than about 10 mm, such as not greater than about 8 mm, not
greater than about 6 mm, or even not greater than about 5 mm. The
distance between fiber bundles also can be within a range between
any of the minimum and maximum values noted above.
[0079] Referring to FIG. 5, embodiments of the body can have has an
adhesion of at least about 1700 lbf, e.g., for a 1-inch bar.
Embodiments of the adhesion of the body can be at least about 1800
lbf, such as at least about 1900 lbf. In other embodiments, the
adhesion can be not greater at least about 2200 lbf, such as not
greater than about 2100 lbf, or even not greater than about 2000
lbf. The adhesion also can be within a range between any of the
minimum and maximum values noted above.
[0080] FIG. 5 also represents abrasive cutting tools having bodies
with an Adhesion Variance Factor (AVF). AVF can be defined as the
relative `spread` of the data points (vertically in FIG. 5) for
each sample. The embodiments disclosed herein may have an AVF of
not greater than about 10%, such as not greater than about 8%, not
greater than about 6%, or even not greater than about 4%. Still
other embodiments have an AVF that is at least 1%, such as at least
2%. The AVF also can be within a range between any of the minimum
and maximum values noted above.
[0081] Embodiments of the reinforcing member can have a fracture
initiation toughness (G.sub.1C) of at least about 3.3 kJ/m.sup.2,
such as at least about 3.4 kJ/m.sup.2, at least about 3.6
kJ/m.sup.2, at least about 3.8 kJ/m.sup.2, at least about 4
kJ/m.sup.2, or even at least about 4.2 kJ/m.sup.2. Other
embodiments can have a G.sub.1C of not greater than about 5
kJ/m.sup.2, such as not greater than about 4.8 kJ/m.sup.2, or even
not greater than about 4.6 kJ/m.sup.2. The G.sub.1C also can be
within a range between any of the minimum and maximum values noted
above.
EXAMPLES
[0082] A comparison of both fracture initiation toughness
(G.sub.1C) and fracture propagation toughness WOF was conducted for
three conventional samples and sample in accordance with an
embodiment herein. The G.sub.1C and WOF tests measure the crack
initiation-energy and crack-propagation stability, respectively.
The G.sub.1C value is determined by measuring the point at which a
crack initiates in a sample with a pre-existing flaw. The WOF is
calculated by measuring the total energy it takes to propagate the
crack through the entire sample. If the crack grows stably, then
the G.sub.1C will be equal to the WOF. When there is unstable
fracture, the initial crack propagates farther than stable growth.
As a result, the unstable WOF is less than the G.sub.1C. With
materials like fiber-reinforced composites, it becomes more
difficult to propagate a crack as the crack grows, so the WOF is
then greater than the G.sub.1C.
[0083] Both G.sub.1C and WOF can be determined from a single
sample, such as a rectangular bar. The test employs a
single-edge-notch (SEN) geometry. The width of the sample (e.g.,
0.5 to 1.5 inches) depends on the number and spacing of the webs. A
0.14-inch notch is cut along on edge of the bar with a 0.005''
thick diamond wheel. The specimen thickness is 0.5-inch, leaving a
0.36-inch uncracked ligament. The notched sample is placed in a
3-point bend fixture with a 2-inch load span. The load is applied
at 0.02 in/min. At the point the crack initiates, the G.sub.1C is
calculated using a technique developed by J G Williams (Fracture
Mechanics of Polymers, Ellis Horwood Ltd, chapter 4 (1984)). After
the initiation, the loading continues until the entire bar is
fractured. The total integrated energy divided by the area of the
original uncracked ligament is the WOF. In addition, WOF also
changes with the web spacing (e.g., about 0.2 to about 1 inch
between webs), which is in turn determined by the width of the
sample.
[0084] The conventional samples CS11, CS12 and CS13 were formed
with IPAC fiberglass webs 103, 24 and 717, respectively, each of
which is commercially available. The sample S11 was formed with web
T700LL, commercially available from Adfors. Sample S11 comprises a
lock leno weave, which is a standard leno weave plus an additional
yarn in the warp direction to lock the leno interlacement and
provide an even greater stability of the fabric. Every other
variable of the samples was identical. The results of this example
appear in Table 1.
TABLE-US-00001 TABLE 1 G.sub.1C (kJ/m.sup.2) WOF (kJ/m.sup.2) CS11
3 +/- 0.8 10 +/- 4.6 CS12 3.2 +/- 1 4.9 +/- 1 CS13 2.6 +/- 0.4 4
+/- 0.5 S11 3.5 +/- 0.9 9 +/- 2
[0085] In addition, and as depicted in FIGS. 4A and 4B, samples
S11, CS11 and CS12 were measured for various parameters such as
thread width and opening width. The various dimensions of the
samples S11, CS11 and CS12 are shown in the table of FIG. 4C. Both
theoretical dimensions and the actual measurements from sample S11
are included.
[0086] Referring again to FIG. 5, an Adhesion Variance Factor (AVF)
may be calculated for the various samples. AVF is defined as the
relative `spread` of the data points (vertically in FIG. 5) for
each sample. Samples CS11, CS12, CS13 and S11 are the same as
described previously herein. Sample CS14 is a conventional sample
commercially available from Adfors as model T350L. For this
testing, 1-inch wide specimens are notched. The root of the notch
is at the edge of the glass web. A wedge is driven into the notch
and specimen is split. This is a type of delamination test called
the "wedge-driven delamination test."
[0087] All of the Adhesion (lbf) data points for S11 are between
about 1835 and 1950 lbf, with an average of about 1892 lbf. Thus,
the AVF for S11 at the upper end is (1950-1892)/1892=3%, and at the
lower end is (1892-1835)/1892=3%, for a total of about 6%.
[0088] In contrast, the AVF at the upper and lower ends of CS11 are
(1981-1900)/1900=4%, and (1900-1613)/1900=15%, respectively, or a
total AVF for CS11 of 19%.
[0089] The AVF at the upper and lower ends of CS12 are
(2037-1875)/1875=9%, and (1875-1346)/1875=28%, respectively, or a
total AVF for CS12 of 37%.
[0090] The AVF at the upper and lower ends of CS13 are
(2035-1625)/1625=25%, and (1625-817)/1625=50%, respectively, or a
total AVF for CS13 of 75%.
[0091] The AVF at the upper and lower ends of CS14 are
(1749-1450)/1450=21%, and (1450-1028)/1450=29%, respectively, or a
total AVF for CS14 of 50%.
[0092] Thus, AVF is much more consistent with the embodiments
disclosed herein than it is for conventional samples.
[0093] Other embodiments may include the following items:
[0094] Item 1. An abrasive article comprising:
[0095] a body including an abrasive portion having:
[0096] a bond material;
[0097] abrasive particles contained in the bond material;
[0098] a reinforcing member contained in the body; wherein
[0099] the abrasive portion has a fracture propagation toughness
WOF of at least about 5 kJ/m.sup.2, and the reinforcing member has
openings with an open area of not greater than about 100 mm.sup.2
within a major plane of the reinforcing member.
[0100] Item 2. The abrasive article of Item 1, wherein the fracture
propagation toughness WOF is at least about 6 kJ/m.sup.2, at least
about 7 kJ/m.sup.2, at least about 8 kJ/m.sup.2, at least about 9
kJ/m.sup.2, at least about 10 kJ/m.sup.2, not greater than about 13
kJ/m.sup.2, not greater than about 12 kJ/m.sup.2, not greater than
about 11 kJ/m.sup.2, not greater than about 10 kJ/m.sup.2.
[0101] Item 3. The abrasive article of Item 1, wherein the
reinforcing member comprises a greige weight of not greater than
about 950 g/m.sup.2, not greater than about 800 g/m.sup.2, not
greater than about 600 g/m.sup.2, not greater than about 500
g/m.sup.2, and not less than about 400 g/m.sup.2, not less than
about 450 g/m.sup.2, not less than about 490 g/m.sup.2.
[0102] Item 4. The abrasive cutting tool of Item 1, wherein the
reinforcing member comprises a maximum thickness of at least about
1 mm, such as at least about 1.1 mm, at least about 1.2 mm, at
least about 1.3 mm, not greater than about 2 mm, not greater than
about 1.8 mm, not greater than about 1.5 mm, not greater than about
1.4 mm.
[0103] Item 5. The abrasive article of Item 1, wherein the
reinforcing member comprises threads with the openings
therebetween, and the threads have a width of not less than about 1
mm, not less than about 1.2 mm, not less than about 1.4 mm, not
less than about 1.6 mm, and not greater than about 4 mm, not
greater than about 3.5 mm, not greater than about 3 mm.
[0104] Item 6. The abrasive cutting tool of Item 1, wherein the
open area is not greater than about 80 mm.sup.2 within the major
plane of the reinforcing member, not greater than about 60
mm.sup.2, not greater than about 40 mm.sup.2, not greater than
about 35 mm.sup.2, not greater than about 30 mm.sup.2, wherein the
open area is at least about 5 mm.sup.2, at least about 8 mm.sup.2,
at least about 10 mm.sup.2, at least about 12 mm.sup.2.
[0105] Item 7. The abrasive article of Item 1, wherein the
reinforcing member comprises fiber bundles with the openings
therebetween, and a distance from one fiber bundle to an adjacent
fiber bundle is at least about 2 mm, at least about 3 mm, at least
about 3.5 mm, and not greater than about 10 mm, not greater than
about 8 mm, not greater than about 6 mm.
[0106] Item 8. The abrasive cutting tool of Item 1, wherein the
openings extend axially through at least a portion of a thickness
thereof, the openings extend entirely through the thickness of the
reinforcing member, wherein the openings have perimeters and define
polygonal two-dimensional shapes.
[0107] Item 9. The abrasive cutting tool of Item 1, wherein the
reinforcing member comprises not greater than about 0.5% of an
average thickness of the body, at least about 1%, at least about
1.1%, at least about 1.2%, not greater than about 5%, not greater
than about 2%, not greater than about 1.5%.
[0108] Item 10. The abrasive cutting tool of Item 1, wherein a
volumetric ratio of the abrasive portion to the reinforcing member
is at least about 5, at least about 10, at least about 15, not
greater than about 20, not greater than about 15, not greater than
about 10.
[0109] Item 11. The abrasive cutting tool of Item 1, wherein the
body has an adhesion of at least about 1700 lbf.
[0110] Item 12. The abrasive article of Item 11, wherein the
adhesion of the body is at least about 1800 lbf, at least about
1900 lbf, and not greater at least about 2200 lbf, not greater than
about 2100 lbf, not greater than about 2000 lbf.
[0111] Item 13. The abrasive cutting tool of Item 1, wherein the
body has an Adhesion Variance Factor (AVF) of not greater than
about 10%.
[0112] Item 14. The abrasive article of Item 13, wherein the AVF of
the body is not greater than about 8%, not greater than about 6%,
not greater than about 4%; at least 1%, at least 2%.
[0113] Item 15. The abrasive article of Item 1, wherein the
reinforcing member has a fracture initiation toughness (G.sub.1C)
of at least about 3.3 kJ/m.sup.2, at least about 3.4 kJ/m.sup.2, at
least about 3.6 kJ/m.sup.2, at least about 3.8 kJ/m.sup.2, at least
about 4 kJ/m.sup.2, at least about 4.2 kJ/m.sup.2, not greater than
about 5 kJ/m.sup.2, not greater than about 4.8 kJ/m.sup.2, not
greater than about 4.6 kJ/m.sup.2.
[0114] Item 16. The abrasive article of Item 1, wherein the
abrasive article has an outer diameter of at least about 50 cm, at
least about 60 cm, at least about 70 cm, at least about 80 cm, at
least about 90 cm, and not greater than about 120 cm, not greater
than about 110 cm, not greater than about 100 cm, not greater than
about 90 cm, not greater than about 80 cm.
[0115] Item 17. The abrasive article of Item 1, wherein the
abrasive article has an axial thickness of at least about 3 cm, at
least about 5 cm, at least about 7 cm, at least about 9 cm, at
least about 11 cm, and not greater than about 18 cm, not greater
than about 16 cm, not greater than about 14 cm, not greater than
about 12 cm, not greater than about 10 cm.
[0116] Item 18. The abrasive article of Item 1, wherein the
abrasive article has an aspect ratio of outer diameter OD to axial
thickness AT (OD:AT) of at least about 2, at least about 5, at
least about 7, at least about 10, at least about 20, and not
greater than about 40, not greater than about 30, not greater than
about 20, not greater than about 15, not greater than about 10.
[0117] Item 19. The abrasive article of Item 1, wherein the body
comprises not greater than about 10 vol % porosity for the total
volume of the body, not greater than about 5 vol %, not greater
than about 4 vol %, not greater than about 3 vol %, not greater
than about 2 vol %, not greater than about 1.5 vol %, not greater
than about 1 vol %, not greater than about 0.8 vol %, not greater
than about 0.5 vol %, not greater than about 0.3 vol %, not greater
than about 0.1 vol %, at least about 0.001 vol %, at least about
0.01 vol %.
[0118] Item 20. The abrasive article of Item 1, wherein the
abrasive article is configured to operate at a speed of at least
about 10,000 sfpm, at least about 11,000 sfpm, at least about
12,000 sfpm.
[0119] Item 21. The abrasive article of Item 1, wherein the
abrasive article is hot pressed.
[0120] Item 22. The abrasive article of Item 1, wherein the
reinforcing member comprises a first reinforcing member, wherein
the first reinforcing member is abutting the abrasive portion,
wherein the first reinforcing member is disposed within the
abrasive portion, wherein the first reinforcing member defines an
external surface of the body, wherein the first reinforcing member
is disposed internally within the body.
[0121] Item 23. The abrasive article of Item 22, wherein the first
reinforcing member extends through an entire diameter of the body,
wherein the first reinforcing member is a planar member comprising
a first major surface and a second major surface, and wherein the
abrasive portion overlies the first major surface, wherein the
abrasive portion is in direct contact with the first major surface
of the first reinforcing member.
[0122] Item 24. The abrasive article of Item 22, further comprising
a second reinforcing member, wherein the first reinforcing member
and the second reinforcing member are spaced apart from each other
within the body, wherein at least a portion of the abrasive portion
is disposed between the first reinforcing member and the second
reinforcing member.
[0123] Item 25. The abrasive article of Item 22, wherein the first
reinforcing member is at least about 0.5% of an average thickness
of the body, at least about 1%, at least about 1.1%, at least about
1.2%, not greater than about 5%, not greater than about 2%, not
greater than about 1.5%.
[0124] Item 26. The abrasive article of Item 1, wherein the bond
material comprises a material selected from the group consisting of
an organic material, an inorganic material, and a combination
thereof, wherein the bond material comprises a material selected
from the group consisting of a metal, a vitreous material, a
ceramic, a resin, and a combination thereof, wherein the bond
material comprises a phenolic resin.
[0125] Item 27. The abrasive article of Item 1, wherein the body
further comprises a filler, wherein the bond material further
comprises a filler, wherein the filler comprises a material
selected from the group consisting of powders, granules, spheres,
fibers, chopped strand fibers (CSF) and a combination thereof,
wherein the filler comprises a material selected from the group
consisting of an inorganic material, an organic material, and a
combination thereof, wherein the filler comprises a material
selected from the group consisting of sand, bubble alumina,
chromites, magnesite, dolomites, bubble mullite, borides, titanium
dioxide, carbon products, silicon carbide, wood flour, clay, talc,
hexagonal boron nitride, molybdenum disulfide, feldspar, nepheline
syenite, glass spheres, glass fibers, CaF.sub.2, KBF.sub.4,
Cryolite (Na.sub.3AlF.sub.6), potassium Cryolite
(K.sub.3AlF.sub.6), pyrite, ZnS, copper sulfide, mineral oil,
fluorides, carbonates, calcium carbonate, saran, phenoxy resin,
CaO, K.sub.2SO.sub.4, mineral wool, MnCl.sub.2, KCl, and a
combination thereof, wherein the filler comprises a material
selected from the group consisting of an antistatic agent, a
lubricant, a porosity inducer, coloring agent, and a combination
thereof.
[0126] Item 28. The abrasive article of Item 1, further comprising
a first filler contained within the abrasive portion comprising
iron and sulfur having an average particle size of not greater than
about 40 microns, wherein the first filler comprises pyrite
(FeS.sub.2), wherein the first filler consists essentially of
pyrite.
[0127] Item 29. The abrasive article of Item 1, wherein the body
comprises at least about 30 vol % bond material for the total
volume of the body, at least about 35 vol %, at least about 40 vol
%, at least about 45 vol %, at least about 50 vol %, at least about
55 vol %, at least about 60 vol %, at least about 65 vol %, and not
greater than about 70 vol %, not greater than about 65 vol %, not
greater than about 60 vol %, not greater than about 55 vol %, not
greater than about 50 vol %, not greater than about 45 vol %, not
greater than about 40 vol %, not greater than about 35 vol %.
[0128] Item 30. The abrasive article of Item 1, wherein the body
comprises at least about 30 vol % abrasive particles for the total
volume of the body, at least about 35 vol %, at least about 40 vol
%, at least about 45 vol %, at least about 50 vol %, at least about
55 vol %, at least about 60 vol %, at least about 65 vol %, and not
greater than about 70 vol %, not greater than about 65 vol %, not
greater than about 60 vol %, not greater than about 55 vol %, not
greater than about 50 vol %, not greater than about 45 vol %, not
greater than about 40 vol %, not greater than about 35 vol %.
[0129] Item 31. The abrasive article of Item 1, wherein the body is
in the form of a bonded abrasive body having a shape selected from
the group consisting of hones, cones, cups, flanged shapes,
cylinders, wheels, rings, and a combination thereof, wherein the
body is a bonded abrasive snagging wheel.
[0130] Item 32. The abrasive article of Item 1, wherein the
reinforcing member comprises an organic material, a polyimide,
polyamide, polyester, aramid, or a combination thereof.
[0131] Item 33. The abrasive article of Item 1, wherein the
reinforcing member comprises an inorganic material, ceramic, glass,
glass-ceramic, or a combination thereof, wherein the reinforcing
member comprises a phenolic resin-based binder.
[0132] Item 34. An abrasive article comprising:
[0133] a body including an abrasive portion having:
[0134] a bond material;
[0135] abrasive particles contained in the bond material;
[0136] a reinforcing member contained in the body; wherein
[0137] the body has an adhesion of at least about 1700 lbf, and an
Adhesion Variance Factor (AVF) of not greater than about 10%.
[0138] Item 35. The abrasive article of Item 34, wherein the
adhesion of the body is at least about 1800 lbf, at least about
1900 lbf, and not greater at least about 2200 lbf, not greater than
about 2100 lbf, not greater than about 2000 lbf.
[0139] Item 36. The abrasive article of Item 34, wherein the
Adhesion Variance Factor (AVF) of the body is not greater than
about 8%, not greater than about 6%, not greater than about 4%; at
least 1%, at least 2%.
[0140] Item 37. An abrasive article comprising:
[0141] a body including an abrasive portion having:
[0142] a bond material;
[0143] abrasive particles contained in the bond material;
[0144] a first filler contained within the abrasive portion
comprising iron and sulfur having an average particle size of not
greater than about 40 microns; and
[0145] a reinforcing member contained in the body, the reinforcing
member comprising:
[0146] (a) a greige weight of not greater than about 950 g/m.sup.2;
or
[0147] (b) a thickness of not greater than about 2 mm; or
[0148] (c) fiber bundles with the openings therebetween, and one
fiber bundle and one opening have a combined dimension of not
greater than about 15 mm; or
[0149] (d) openings with an open area of not greater than about 100
mm.sup.2.
[0150] Item 38. The abrasive article of Item 1, wherein the
reinforcing member comprises a lock leno weave.
[0151] The processes and abrasive articles disclosed herein
represent a departure from the state-of-the-art. Abrasive articles
herein can utilize a combination of features, such as abrasive
particle having certain features, including but limited to,
composition, average pore size, average porosity, average crystal
size, crystal shape, and a combination thereof. Moreover, the
abrasive articles may utilize additional features such as bond
material, content of bond material, content of abrasive particles,
fillers, and the like. While not entirely understood, the
combination of features facilitates the formation of abrasive
articles that have demonstrated unexpected and remarkable improved
performance.
[0152] The above-disclosed subject matter is to be considered
illustrative, and not restrictive, and the appended claims are
intended to cover all such modifications, enhancements, and other
embodiments, which fall within the true scope of the present
invention. Thus, to the maximum extent allowed by law, the scope of
the present invention is to be determined by the broadest
permissible interpretation of the following claims and their
equivalents, and shall not be restricted or limited by the
foregoing detailed description.
[0153] The Abstract is provided to comply with Patent Law and is
submitted with the understanding that it will not be used to
interpret or limit the scope or meaning of the claims. In addition,
in the foregoing Detailed Description, various features may be
grouped together or described in a single embodiment for the
purpose of streamlining the disclosure. This disclosure is not to
be interpreted as reflecting an intention that the claimed
embodiments require more features than are expressly recited in
each claim. Rather, as the following claims reflect, inventive
subject matter may be directed to less than all features of any of
the disclosed embodiments. Thus, the following claims are
incorporated into the Detailed Description, with each claim
standing on its own as defining separately claimed subject
matter.
* * * * *