U.S. patent application number 14/462876 was filed with the patent office on 2015-03-05 for abrasive article and method of forming.
The applicant listed for this patent is Saint-Gobain Abrasifs, Saint-Gobain Abrasives, Inc.. Invention is credited to John M. GULCIUS, Cecile O. MEJEAN, Srinivasan RAMANATH, Rachana UPADHYAY, Ramanujam VEDANTHAM.
Application Number | 20150059256 14/462876 |
Document ID | / |
Family ID | 52581208 |
Filed Date | 2015-03-05 |
United States Patent
Application |
20150059256 |
Kind Code |
A1 |
MEJEAN; Cecile O. ; et
al. |
March 5, 2015 |
ABRASIVE ARTICLE AND METHOD OF FORMING
Abstract
An abrasive article including a bonded abrasive body including a
bond material having a metal, abrasive particles contained within
the bond material, and a filler blend including fine filler
particles and coarse filler particles and defining a filler
particle size ratio (Ff/Fc) of not greater than about 0.97, where
Ff represents the average particle of the fine filler particles and
Fc represents the average particle size of the coarse filler
particles.
Inventors: |
MEJEAN; Cecile O.;
(Marlborough, MA) ; RAMANATH; Srinivasan; (Holden,
MA) ; GULCIUS; John M.; (Shrewsbury, MA) ;
VEDANTHAM; Ramanujam; (Worcester, MA) ; UPADHYAY;
Rachana; (Shrewsbury, MA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Saint-Gobain Abrasives, Inc.
Saint-Gobain Abrasifs |
Worcester
Confians-Sainte-Honorine |
MA |
US
FR |
|
|
Family ID: |
52581208 |
Appl. No.: |
14/462876 |
Filed: |
August 19, 2014 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
61871942 |
Aug 30, 2013 |
|
|
|
Current U.S.
Class: |
51/309 |
Current CPC
Class: |
B24D 3/06 20130101 |
Class at
Publication: |
51/309 |
International
Class: |
B24D 3/06 20060101
B24D003/06 |
Claims
1. An abrasive article comprising: a bonded abrasive body
including: a bond material comprising a metal; abrasive particles
contained within the bond material; a filler blend including fine
filler particles and coarse filler particles and defining a filler
particle size ratio (Ff/Fc) of not greater than about 0.97, wherein
the Ff represents the average particle of the fine filler particles
and Fc represents the average particle size of the coarse filler
particles.
2. The abrasive article of claim 1, wherein the body comprises a
porosity of not greater than about 14 vol % for a total volume of
the bonded abrasive body.
3. The abrasive article of claim 1, wherein the fine filler
particles and the coarse filler particles comprise a same
element.
4. The abrasive article of claim 1, wherein fine filler particles
comprise an average particle size of at least about 5 microns and
not greater than about 120 microns.
5. The abrasive article of claim 1, wherein coarse filler particles
comprise an average particle size of at least about 15 microns and
not greater than about 200 microns.
6. The abrasive article of claim 1, wherein the filler particle
size ratio (Ff/Fc) is at least about 0.03 and not greater than
about 0.95.
7. The abrasive article of claim 1, wherein the filler blend
comprises a filler content ratio (Cf/Cc) of at least about 0.05 and
not greater than about 10, wherein Cf represents the volume percent
of fine filler particles for the total volume of the bonded
abrasive body and Cc represents the volume percent of the coarse
filler particles for the total volume of the bonded abrasive
body.
8. The abrasive article of claim 1, wherein the bonded abrasive
body comprises at least about 1 vol % and not greater than about 50
vol % of the filler blend for the total volume of the bonded
abrasive body.
9. The abrasive article of claim 1, wherein the bonded abrasive
body comprises at least about 1 vol % and not greater than about 25
vol % of the fine filler particles for the total volume of the
bonded abrasive body.
10. The abrasive article of claim 1, wherein the bonded abrasive
body comprises at least about 1 vol % and not greater than about 25
vol % of the coarse filler particles for the total volume of the
bonded abrasive body.
11. The abrasive article of claim 1, wherein the bond material
comprises a transition metal element selected from the group
consisting of copper, tin, silver, nickel, and a combination
thereof.
12. The abrasive article of claim 1, wherein the bond material
comprises bronze including copper (Cu) and tin (Sn) and wherein the
bronze comprises a content of copper that is not less than a
content of tin.
13. The abrasive article of claim 1, wherein the bonded abrasive
body comprises at least about 10 vol % of the bond material for the
total volume of the bonded abrasive body.
14. The abrasive article of claim 1, wherein the bonded abrasive
body comprises not greater than about 85 vol % of the bond material
for the total volume of the bonded abrasive body.
15. An abrasive article comprising: a bonded abrasive body
including: a bond material comprising a metal; abrasive particles
contained within the bond material; a filler blend comprising: fine
filler particles contained in the bond material having a Mohs
hardness of not greater than about 4; coarse filler particles
contained in the bond material having a Mohs hardness of not
greater than about 6; and a porosity of not greater than about 15
vol %.
16. The abrasive article of claim 15, wherein the fine filler
particles and the coarse filler particles comprise a same
element.
17. The abrasive article of claim 15, wherein fine filler particles
comprise an average particle size of at least about 5 microns and
not greater than about 120 microns.
18. The abrasive article of claim 15, wherein coarse filler
particles comprise an average particle size of at least about 15
microns and not greater than about 200 microns.
19. The abrasive article of claim 15, wherein the filler blend
comprises a filler content ratio (Cf/Cc) of at least about 0.05 and
not greater than about 10, wherein Cf represents the volume percent
of fine filler particles for the total volume of the bonded
abrasive body and Cc represents the volume percent of the coarse
filler particles for the total volume of the bonded abrasive
body.
20. The abrasive article of claim 15, wherein the bond material
comprises bronze including copper (Cu) and tin (Sn) and wherein the
bronze comprises a content of copper that is not less than a
content of tin.
Description
CROSS-REFERENCE TO RELATED APPLICATION(S)
[0001] This application claims priority under 35 U.S.C.
.sctn.119(e) to U.S. Patent Application No. 61/871,942 entitled
"Abrasive Article and Method of Forming," by inventors Cecile O.
Mejean, Srinivasan Ramanath, John M. Gulcius, Ramanuj am Vedantham,
and Rachana Upadhyay, filed Aug. 30, 2013, which is assigned to the
current assignee hereof and incorporated herein by reference in its
entirety.
BACKGROUND
[0002] 1. Field of the Disclosure
[0003] The following is directed to methods of forming abrasive
articles, and particularly, bonded abrasive articles.
[0004] 2. Description of the Related Art
[0005] A variety of abrasive tools have been developed over the
past century for various industries for the general function of
removing material from a workpiece, including for example, sawing,
drilling, polishing, cleaning, carving, and grinding. In the
production of electronic devices, the back surface of a
semiconductor wafer having a plurality of circuits such as IC's and
LSI's is ground to a predetermined thickness by a grinding machine
before it is divided into individual chips. To grind the back
surface of the semiconductor wafer efficiently, a grinding machine
equipped with a rough grinding unit and a finish grinding unit is
generally used. Generally, the article utilize to conduct the rough
grinding process is a bonded abrasive body or grindstone, which is
obtained by bonding together diamond abrasive grains having a
relatively large size with a vitrified bond or metal bond material.
A resin bond grindstone having diamond abrasive grains of a median
particle size of 2 microns or more contained in a resin bond is
typically used for finish grinding operations. Smaller sizes of
diamonds generally cannot be utilized in resin bonded articles.
[0006] In some cases, the content of the inorganic bonding agent is
reduced and the content of porosity is increased, which is
considered to reduce glazing or clogging of the surface of the
vitrified grindstone, chipping of the abrasive structure, poor
dressability of the grindstone, and other drawbacks. Generally,
high-porosity grindstone bodies are accomplished by the use of
foaming agents during forming, which create bubbles and thus
porosity in the finally-formed abrasive product.
[0007] Still, the industry continues to demand improved grindstone
materials, capable of achieving improved grinding performance.
SUMMARY
[0008] According to a first aspect, an abrasive article includes a
bonded abrasive body including a bond material comprising a metal,
abrasive particles contained within the bond material, and a filler
blend including fine filler particles and coarse filler particles
and defining a filler particle size ratio (Ff/Fc) of not greater
than about 0.97, wherein the Ff represents the average particle of
the fine filler particles and Fc represents the average particle
size of the coarse filler particles.
[0009] In another aspect, an abrasive article includes a bonded
abrasive body having a bond material comprising a metal, abrasive
particles contained within the bond material, a filler blend
including fine filler particles contained in the bond material
having a Mohs hardness of not greater than about 4 and coarse
filler particles contained in the bond material having a Mohs
hardness of not greater than about 6. The bonded abrasive body
further includes a porosity of not greater than about 15 vol %.
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 plot of cumulative wheel wear of the
bonded abrasive body in microns versus cumulative material removed
from the workpiece in microns.
[0012] FIG. 2 includes a plot of percent maximum power versus time
for the backgrinding operation.
DETAILED DESCRIPTION
[0013] The following is directed towards fixed abrasive articles,
and more particularly bonded abrasive articles including a
plurality of abrasive particles contained within a three
dimensional matrix of bond material. The bonded abrasive article
may be suitable for grinding a workpiece and material removal
operations. In certain instances, the bonded abrasive article may
be particularly suited for grinding of hard materials, and more
particularly, hard, single crystalline materials, such a sapphire
wafers.
[0014] In accordance with an embodiment, the process of forming a
bonded abrasive article can include the formation of a mixture. The
mixture may be in a wet or dry form. Furthermore, the mixture may
include certain components, including but not limited to, a bond
material, abrasive particles, and a filler blend. It will be
appreciated that other components may be added to the mixture to
facilitate proper dispersion of the components within each other
and further processing to form the finally-formed bonded abrasive
article.
[0015] After properly forming the mixture, the process of forming
the bonded abrasive body can include forming a green body, which
can be an unsintered body, which may undergo further treatment to
form the finally-formed abrasive article. Suitable methods of
forming the green body can include molding, pressing, casting,
punching, and a combination thereof. Optionally, forming of the
green body may include drying of the green body to facilitate
removal of volatiles and prepare the body for further
processing.
[0016] After forming the green body, the process of forming the
bonded abrasive article can continue by heating the green body to
form a finally-formed bonded abrasive body. Heating of the green
body may facilitate a phase transformation of one or more
components of the body, including for example a bond material. In
certain instances, heating up the body can be conducted at a
temperature of at least about 375.degree. C. to about 700.degree.
C. In more particular instances, the forming process may include
hot pressing, which can include applying heat and pressure to the
green body, which may be applied separately or simultaneously. In
accordance with one embodiment, the pressure applied can be at
least about 0.5 tons/in.sup.2 and not greater than about 3
tons/in.sup.2.
[0017] After processing, the finally-formed abrasive article can
include a bonded abrasive body including a certain content of bond
material, a certain content of abrasive particles contained within
the bond material, a filler blend contained within the bond
material, and some porosity extending throughout the volume of the
bonded abrasive body. In accordance with an embodiment, the filler
blend can include fine filler particles and coarse filler particles
that can be distinct from each other.
[0018] In accordance with an embodiment, the fine filler particles
can include a material incorporated into the finally-formed
abrasive body. For example, in certain instances, the fine filler
particles may be a permanent material, which may be present as a
particulate material in the finally-formed abrasive article.
Moreover, in certain instances, the fine filler particles may not
necessarily be removed during processing, such as a pore-forming
material. In accordance with one embodiment, the fine filler
particles may include an inorganic material. More particularly, the
fine filler particles may include a carbon-containing material. For
example, the fine filler particles can include a carbon-base
material, wherein at least about 51% of the material of the fine
filler particles includes carbon. In accordance with one particular
embodiment, the fine filler particles can include graphite, and
more particularly, may consist essentially of graphite.
[0019] In certain instances, the fine filler particles can have an
average particle size that is not greater than about 120 microns.
For example, the fine filler particles can have an average particle
size that is not greater than about 110 microns, not greater than
about 100 microns, not greater than about 90 microns, not greater
than about 80 microns, not greater than about 70 microns, not
greater than about 60 microns, not greater than about 50 microns,
not greater than about 40 microns, not greater than about 30
microns, not greater than about 20 microns, or even not greater
than about 10 microns. Still, the fine filler particles may have
any average particle size that can be at least about 0.1 microns,
such as at least about 1 micron, at least about 5 microns, or even
at least about 10 microns. It will be appreciate that the fine
filler particles can have an average particle size within a range
between any of the minimum and maximum values noted above.
[0020] In accordance with an embodiment, the fine filler particles
may have a particular Mohs hardness to facilitate formation and
performance of the bonded abrasive body. For example, the fine
filler particles contained within the bond material may have a Mohs
hardness of not greater than about 4. In other embodiments, the
fine filler particles contained within the bond material may have a
Mohs hardness of not greater than about 3.5, or even not greater
than about 3. Still, the fine filler particles contained within the
bond material may have a Mohs hardness of at least about 1, such as
at least about 1.5, or even at least about 2. It will be
appreciated that the fine filler particles can have a Mohs hardness
within a range between any of the minimum and maximum values noted
above.
[0021] The fine filler particles may have a certain morphology that
facilitates performance of the bonded abrasive article. For
example, the fine filler particles can have a shape selected from
the group consisting of circular, ellipsoidal, needle-like,
irregular, and platelet. In one particular embodiment, the fine
filler particles can have a platelet shape. More particularly, the
fine filler particles may have an aspect ratio (1:t) of length (1),
which is the greatest dimension of the particle to thickness (t)
which is the smallest dimension of the particle, of at least about
1:2, such as at least about 1:3, or even at least about 1:4.
[0022] In accordance with another embodiment, the coarse filler
particles can include a material incorporated into the
finally-formed abrasive body. In certain instances, the coarse
filler particles may be a permanent material, which may be present
as a particulate material in the finally-formed abrasive article.
Moreover, the coarse filler particles may not necessarily be
removed during processing, such as a pore-forming material. In
accordance with one embodiment, the coarse filler particles may
include an inorganic material. In at least one aspect, the coarse
filler particles may include a carbon-containing material. For
example, the coarse filler particles can include a carbon-base
material, wherein at least about 51% of the material of the coarse
filler particles includes carbon. In accordance with one particular
embodiment, the coarse filler particles can include graphite, and
more particularly, may consist essentially of graphite.
[0023] In certain instances, the fine filler particles and coarse
filler particles may include a same element, composition, or
material. For example, the fine filler particles and coarse filler
particles may include a same carbon-containing material, wherein
the fine filler particle includes at least 51% carbon and the
coarse filler particle includes at least about 51% carbon. In one
aspect, the fine filler particles and coarse filler particles may
include a same carbon-based material. For example, in one
embodiment, the fine filler particles and coarse filler particles
may include graphite, and more particularly, the fine filler
particles can consist essentially of graphite and the coarse filler
particles can consist essentially of graphite.
[0024] In certain instances, the coarse filler particles may have a
particular average particle size. For example, the coarse filler
particles can have an average particle size of not greater than
about 200 microns, such as not greater than about 190 microns, not
greater than about 180 microns, not greater than about 170 microns,
not greater than about 160 microns, not greater than about 150
microns, not greater than about 140 microns, not greater than about
130 microns. In still another non-limiting embodiment, the coarse
filler particles can have an average particle size of at least
about 15 microns, such as at least about 20 microns, at least about
30 microns, at least about 40 microns, at least about 50 microns,
at least about 60 microns, at least about 70 microns, at least
about 80 microns, at least about 90 microns, or even at least about
100 microns. It will be appreciated that the coarse filler
particles can have an average particle size within a range between
any of the minimum and maximum values noted above.
[0025] In accordance with an embodiment, the coarse filler
particles may have a particular hardness to facilitate formation
and performance of the bonded abrasive body. For example, the
coarse filler particles can have a Mohs hardness of not greater
than about 6, such as not greater than about 5.5, not greater than
about 5, or even not greater than about 4, not greater than about
3.5. Still, in at least one non-limiting embodiment, the coarse
filler particles contained in the bond material can have a Mohs
hardness of at least about 1, such as at least about 1.5, or even
at least about 2. It will be appreciated that the coarse filler
particles contained in the bond material can have a Mohs hardness
within a range between any of the minimum and maximum values noted
above.
[0026] The coarse filler particles may have a certain morphology
that facilitates performance of the bonded abrasive article. For
example, the coarse filler particles can have a shape selected from
the group consisting of circular, ellipsoidal, needle-like,
irregular, and platelet. In one particular embodiment, the coarse
filler particles can have a platelet shape. More particularly, the
coarse filler particles may have an aspect ratio (1:t) of length
(1), which is the greatest dimension of the particle to thickness
(t) which is the smallest dimension of the particle, of at least
about 1:2, such as at least about 1:3, or even at least about
1:4.
[0027] In one aspect, the fine filler particles may have an average
particle size (Ff) that is distinct from the average particle size
of the coarse filler (Fc). More particularly, the filler blend may
include a particular filler particle size ratio (Ff/Fc) that may be
not greater than about 0.97. For example, in one embodiment, the
filler particle size ratio (Ff/Fc) can be not greater than about
0.95, such as not greater than about 0.93, not greater than about
0.9, not greater than about 0.88, not greater than about 0.85, not
greater than about 0.83, not greater than about 0.8, not greater
than about 0.78, not greater than about 0.75, not greater than
about 0.73, not greater than about 0.7, not greater than about
0.68, not greater than about 0.65, not greater than about 0.63, not
greater than about 0.6, not greater than about 0.58, not greater
than about 0.55, not greater than about 0.53, not greater than
about 0.5, not greater than about 0.48, not greater than about
0.45, not greater than about 0.43, not greater than about 0.4, not
greater than about 0.3, not greater than about 0.2, or even not
greater than about 0.1. Still, in another non-limiting embodiment,
the filler particle size ratio (Ff/Fc) can be at least about 0.3,
such as at least about 0.5, at least about 0.8, at least about 0.1,
at least about 0.13, at least about 0.15, at least about 0.18, at
least about 0.2, at least about 0.23, at least about 0.25, at least
about 0.28, at least about 0.3, at least about 0.33, at least about
0.35, at least about 0.38, at least about 0.4, at least about 0.43,
at least about 0.45, at least about 0.48, at least about 0.5, at
least about 0.53, at least about 0.55, at least about 0.58, at
least about 0.6, at least about 0.63, at least about 0.65, at least
about 0.68, at least about 0.7, at least about 0.73, at least about
0.75, at least about 0.78, at least about 0.8, or even at least
about 0.9. It will be appreciated that the filler particle size
ratio can be within a range between any of the above minimum and
maximum values.
[0028] In further instances, the filler blend may include a
particular filler content ratio (Cf/Cc) of at least about 0.1,
wherein Cf represents the volume percent of fine filler particles
for the total volume of the bonded abrasive body and Cc represents
the volume percent of the coarse filler particles for the total
volume of the bonded abrasive body. In one embodiment, the filler
content ratio can be at least about 0.05, such at least about 0.1,
at least about 0.2, at least about 0.3, at least about 0.4, at
least about 0.5, at least about 0.6, at least about 0.7, at least
about 0.8, at least about 0.9, at least about 1, at least about
1.1, at least about 1.2, at least about 1.3, at least about 1.4, or
even at least about 1.5. In still another non-limiting embodiment,
the filler content ratio of the bonded abrasive body can be not
greater than about 10, such as not greater than about 9, not
greater than about 8, not greater than about 7, not greater than
about 6, not greater than about 5, not greater than about 4, not
greater than about 3, not greater than about 2, not greater than
about 1, not greater than about 0.95, not greater than about 0.9,
not greater than about 0.8, not greater than about 0.7, not greater
than about 0.6, not greater than about 0.5, not greater than about
0.4, not greater than about 0.3, not greater than about 0.2, not
greater than about 0.1. It will be appreciated that the bonded
abrasive body may have a filler content ratio within a range
between any of the minimum and maximum values noted above.
[0029] In more particular instances, the bonded abrasive body may
include a particular content of the filler blend to facilitate the
characteristics of the embodiments herein. For example, in one
embodiment the bonded abrasive body may include at least 1 vol. %
filler blend for the total volume of the bonded abrasive body. In
other instances, the content of the filler blend within the bonded
abrasive body can be greater, such as at least about 3 vol. %, at
least about 5 vol. %, at least about 8 vol. %, at least about 10
vol. %, at least about 13 vol. %, at least about 15 vol. %, or even
at least about 18 vol. % for the total volume of the bonded
abrasive body. Still, in other non-limiting embodiments, the bonded
abrasive body may include not greater than about 50 vol. % of the
filler blend, such as not greater than about 45 vol. %, not greater
than about 40 vol. %, not greater than about 35 vol. %, not greater
than about 30 vol. %, not greater than about 28 vol. %, not greater
than about 25 vol. %, or even not greater than about 22 vol. % for
the total volume of the bonded abrasive body. It will be
appreciated that the bonded abrasive body may include a content of
filler blend within a range between any of the minimum and maximum
percentages noted above.
[0030] In still another embodiment, the bonded abrasive body may
include a certain content of the fine filler for the total volume
of the bonded abrasive body. For example, the bonded abrasive body
may include at least about 1 vol. %, such as at least about 2 vol.
%, at least about 3 vol. %, at least about 4 vol. %, at least about
5 vol. %, at least about 6 vol. %, at least about 7 vol. %, or even
at least about 8 vol. % fine filler particles for the total volume
of the bonded abrasive body. In another non-limiting embodiment,
the bonded abrasive body may include not greater than about 25 vol.
%, such as not greater than about 22 vol. %, not greater than about
20 vol. %, not greater than about 18 vol. %, not greater than about
16 vol. %, not greater than about 13 vol. %, or even not greater
than about 10 vol. % of the fine filler particles for the total
volume of the bonded abrasive body. It will be appreciated that the
total content of the fine filler particles for the total volume of
the bonded abrasive body can be within range between any of the
minimum and maximum percentages noted above.
[0031] In still another aspect, the bonded abrasive body may
include a particular content of coarse filler particles for the
total volume of the bonded abrasive body. For example, the bonded
abrasive body may include at least 1 vol. %, such as at least about
2 vol. %, at least about 3 vol. %, at least about 4 vol. %, at
least about 5 vol. %, at least about 6 vol. %, at least about 7
vol. %, or even at least about 8 vol. % coarse filler particles for
the total volume of the bonded abrasive body. In still other
instances, the bonded abrasive body may include not greater than
about 25 vol. %, not greater than about 22 vol. %, not greater than
about 20 vol. %, not greater than about 18 vol. %, not greater than
about 16 vol. %, not greater than about 13 vol. %, or even not
greater than about 10 vol. % coarse filler particles for the total
volume of the bonded abrasive body. It will be appreciated that the
bonded abrasive body may include content of coarse filler particles
for the total volume of the bonded abrasive body within a range
between any of the minimum and maximum percentages noted above.
[0032] In another embodiment, the bonded abrasive body may include
a particular content of abrasive particles for the total volume of
the bonded abrasive body. For example, in certain instances, the
bonded abrasive body may include not greater than about 85 vol. %,
such as not greater than about 82 vol. %, not greater than about 80
vol. %, not greater than about 75 vol. %, not greater than about 70
vol. %, not greater than about 65 vol. %, or even not greater than
about 60 vol. % abrasive particles for the total volume of the
bonded abrasive body. In yet another non-limiting embodiment, the
bonded abrasive body may include at least about 10 vol. %, such as
at least about 15 vol. %, at least about 20 vol. %, at least about
25 vol. %, at least about 30 vol. %, at least about 35 vol. %, at
least about 40 vol. %, or even at least about 45 vol. % abrasive
particles for the total volume of the bonded abrasive body. It will
be appreciated that the content of abrasive particles for the total
volume of the bonded abrasive body may be within a range between
any of the minimum and maximum percentages noted above.
[0033] In accordance with an embodiment, the bonded abrasive body
may be formed of particular size of abrasive particles. For
example, the abrasive particles may have an average particle size
of not greater than about 200 microns. In other embodiments, the
average particle size of the abrasive particles may be not greater
than about 180 microns, such as not greater than about 150 microns,
not greater than about 130 microns, not greater than about 110
microns, not greater than about 100 microns, not greater than about
80 microns, not greater than about 70 microns, not greater than
about 65 microns, not greater than about 60 microns, not greater
than about 55 microns, not greater than about 50 microns, or even
not greater than about 45 microns. In still other embodiments, the
abrasive particles may have an average particle size of at least
about 0.5 microns, such as at least about 1 micron, at least about
2 microns, at least about 5 microns, at least about 8 microns, at
least about 10 microns, at least about 15 microns, at least about
20 microns, at least about 25 microns, or even at least about 30
microns. It will be appreciated that the abrasive particles can
have an average particle size within a range between any of the
minimum and maximum values noted above.
[0034] Furthermore, the abrasive particles can have a particular
hardness with respect to the fine filler particle. For example, the
abrasive particles can have a hardness that is greater than the
fine filler particle. In certain instances, the abrasive particles
can have a hardness that is at least about 7 with respect Mohs
hardness. In other embodiments, the abrasive particles can have a
Mohs hardness of about 7.5, such as at least about 8, at least
about 8.5, or even at least about 9.
[0035] The abrasive article may use an abrasive particle
hardness-to-fine filler particle hardness ratio (Hap/Hff), wherein
Hap represents the Mohs hardness of the abrasive particles and Hff
represents the Mohs hardness of the fine filler particles. In at
least one embodiment, the abrasive particle hardness-to-fine filler
particle hardness ratio (Hap/Hff) can be at least about 1, such as
at least about 1.05, at least about 1.1, at least about 1.2, at
least about 1.3, at least about 1.4, at least about 1.5, at least
about 1.6, at least about 1.7, at least about 1.8, at least about
1.9, at least about 2, at least about 2.1, at least about 2.2, at
least about 2.5, at least about 2.7, at least about 3. Still, in
one non-limiting embodiment, the abrasive particle hardness-to-fine
filler particle hardness ratio (Hap/Hff) can be not greater than
about 10, such as not greater than about 9, not greater than about
8, not greater than about 7, not greater than about 6, not greater
than about 5, not greater than about 4, or even not greater than
about 3. It will be appreciated that the abrasive particle
hardness-to-fine filler particle hardness ratio (Hap/Hff) can be
within a range between any of the above minimum and maximum
values.
[0036] Moreover, the abrasive particles may have a particular
hardness with respect to the coarse filler particle. For example,
the abrasive particles can have a hardness that is greater than the
coarse filler particle. In one particular embodiment, the abrasive
article may incorporate a specific abrasive particle
hardness-to-coarse filler particle hardness ratio (Hap/Hcf),
wherein Hap represents the Mohs hardness of the abrasive particles
and Hcf represents the Mohs hardness of the coarse filler
particles. In at least one embodiment, the abrasive particle
hardness-to-coarse filler particle hardness ratio (Hap/Hff) can be
at least about 1, such as at least about 1.05, at least about 1.1,
at least about 1.2, at least about 1.3, at least about 1.4, at
least about 1.5, at least about 1.6, at least about 1.7, at least
about 1.8, at least about 1.9, at least about 2, at least about
2.1, at least about 2.2, at least about 2.5, at least about 2.7, at
least about 3. Still, in one non-limiting embodiment, the abrasive
particle hardness-to-coarse filler particle hardness ratio
(Hap/Hff) can be not greater than about 10, such as not greater
than about 9, not greater than about 8, not greater than about 7,
not greater than about 6, not greater than about 5, not greater
than about 4, or even not greater than about 3. It will be
appreciated that the abrasive particle hardness-to-coarse filler
particle hardness ratio (Hap/Hff) can be within a range between any
of the above minimum and maximum values.
[0037] In certain instances, the bonded abrasive body may include
abrasive particles that are formed of an inorganic material. More
particularly, the abrasive particles can include a naturally
occurring material or mineral. In yet another embodiment, the
abrasive particles may include a synthesized material. Accordingly
to at least one embodiment, the abrasive particles can include
materials such as oxides, carbides, nitrides, borides, oxycarbides,
oxynitrides, oxyborites, carbon-containing materials, diamond,
cubic boron nitride, and a combination thereof. For example, in one
particular instance, the abrasive particles can include a super
abrasive material such as diamond or cubic boron nitride. More
particularly, in at least one aspect, the abrasive particles can
consist essentially of diamond.
[0038] For embodiments utilizing abrasive particles including
diamond, the abrasive particles may have a particular content of
polycrystalline diamond. For example, the content of
poly-crystalline diamond for the total content of abrasive
particles may be at least about 20%, such as at least about 25%, at
least about 30%, at least about 40%, at least about 50%, at least
about 60%, at least about 70%, at least about 80%, or even at least
about 90%. In at least one embodiment, essentially, essentially all
of the diamond of the abrasive particles is a polycrystalline
diamond material.
[0039] In certain instances, the bonded abrasive body can include a
bond material including a metal or metal alloy. In particular
embodiments, the bond material may include a transition metal
element, and more particularly, may include a transition metal
element, such as copper, tin, silver, nickel, and a combination
thereof. In at least one embodiment, the bond material can include
bronze including a combination of copper and tin. For example, the
bond material including bronze may include a content of copper that
is not less than a content of tin. In still other alternative
embodiments, the bronze may include a content of copper that is
greater than a content of tin.
[0040] In one aspect, the bonded abrasive body can include a bond
material including bronze having a copper-to-tin ratio (Cu/An) of
at least about 0.2. In other embodiments, the bronze can include a
copper-to-tin ratio of at least about 0.23, such as at least about
0.25, at least about 0.28, at least about 0.3, at least about 0.33,
at least about 0.35, at least about 0.38, at least about 0.4, at
least about 0.43, at least about 0.45, at least about 0.48, at
least about 0.5, at least about 0.53, at least about 0.55, at least
about 0.58, at least about 0.6, at least about 0.63, at least about
0.65, at least about 0.68, at least about 0.7, at least about 0.73,
at least about 0.75, at least about 0.78, at least about 0.8, or
even at least about 0.9. In another non-limiting embodiment, the
bond material can include bronze having a copper-to-tin ratio of
not greater than about 0.93, not greater than about 0.9, not
greater than about 0.88, not greater than about 0.85, not greater
than about 0.83, not greater than about 0.8, not greater than about
0.78, not greater than about 0.75, not greater than about 0.73, not
greater than about 0.7, not greater than about 0.68, not greater
than about 0.65, not greater than about 0.63, not greater than
about 0.6, not greater than about 0.58, not greater than about
0.55, not greater than about 0.53, not greater than about 0.5, not
greater than about 0.48, not greater than about 0.45, not greater
than about 0.43, not greater than about 0.4, not greater than about
0.3, not greater than about 0.2. It will be appreciated that the
bond material can include bronze having a copper-to-tin ratio
within a range between any of the minimum and maximum values noted
above.
[0041] In at least one aspect, the bonded abrasive body may include
a particular content of bond material for the total volume of the
bonded abrasive body. For example, the bonded abrasive body may
include at least about 10 vol. % bond material, such as at least
about 15 vol. %, at least about 20 vol. %, at least about 25 vol.
%, at least about 30 vol. %, at least about 35 vol. %, at least
about 40 vol. %, or even at least about 45 vol. % for the total
volume of the bonded abrasive body. Still, in another non-limiting
embodiment, the bonded abrasive body may include not greater than
about 85 vol. % bond material, such as not greater than about 82
vol. %, not greater than about 80 vol. %, not greater than about 75
vol. %, not greater than about 70 vol. %, or even not greater than
about 65 vol. % bond material for a total volume of the bonded
abrasive body. It will be appreciated that the bonded abrasive body
may include a content of bond material within a range between any
of the minimum and maximum percentages noted above.
[0042] The bonded abrasive body may include a limited content of
certain materials, including for example phosphorous, zinc,
antimony, chromium, cobalt, silicon, and a combination thereof. For
example, in one embodiment, the content of phosphorous can be not
greater than about 1 vol. %, such as not greater than about 0.08
vol. %, such as not greater than about 0.05 vol. %, or even not
greater than about 0.01 vol. % for the total volume of the bond
material. Still, in certain non-limiting embodiments, the bond
material may include a trace amount, such as at least about 0.001
vol. % for the total volume of the bond material.
[0043] In accordance with an embodiment, the bonded abrasive body
may have a certain content of porosity to facilitate performance
characteristics. For example, the porosity of the body may be not
greater than about 15 vol. % for the total volume of the body. In
other instances, the body may include a porosity of not greater
than about 14 vol. %, such as not greater than about 13 vol. %, not
greater than about 12 vol. %, not greater than about 11 vol. %, not
greater than about 10 vol. %, not greater than about 9 vol. %, not
greater than about 8 vol. %, not greater than about 7 vol. %, not
greater than about 6 vol. %, not greater than about 5 vol. %, not
greater than about 4 vol. %, not greater than about 3 vol. %.
Still, in at least one non-limiting embodiment, the porosity of the
body can be at least about 0.1 vol. %, such as at least about 0.5
vol. %, at least about 1 vol. %, or even at least about 1.5 vol. %.
It will be appreciated that the body can have a content of porosity
within a range between any of the minimum and maximum percentages
noted above.
[0044] Many different aspects and embodiments are possible. Some of
those aspects and embodiments are described below. After reading
this specification, skilled artisans will appreciate that those
aspects and embodiments are only illustrative and do not limit the
scope of the present invention. Embodiments may be in accordance
with any one or more of the items as listed below.
[0045] Item 1. An abrasive article comprising: a bonded abrasive
body including: a bond material comprising a metal; abrasive
particles contained within the bond material; a filler blend
including fine filler particles and coarse filler particles and
defining a filler particle size ratio (Ff/Fc) of not greater than
about 0.97, wherein the Ff represents the average particle of the
fine filler particles and Fc represents the average particle size
of the coarse filler particles.
[0046] Item 2. An abrasive article comprising: a bonded abrasive
body including: a bond material comprising a metal; abrasive
particles contained within the bond material; a filler blend
comprising: fine filler particles contained in the bond material
having a Mohs hardness of not greater than about 4; coarse filler
particles contained in the bond material having a Mohs hardness of
not greater than about 6; and a porosity of not greater than about
15 vol %.
[0047] Item 3. The abrasive article of any of items 1 and 2,
wherein the body comprises a porosity of not greater than about 14
vol % for a total volume of the bonded abrasive body, not greater
than about 13 vol %, not greater than about 12 vol %, not greater
than about 11 vol %, not greater than about 10 vol %, not greater
than about 9 vol %, not greater than about 8 vol %, not greater
than about 7 vol %, not greater than about 6 vol %, not greater
than about 5 vol %, not greater than about 4 vol %, not greater
than about 3 vol %, and at least about 0.1 vol %.
[0048] Item 4. The abrasive article of any of items 1 and 2,
wherein the fine filler particles comprise an inorganic material,
wherein the fine filler particles comprise a carbon-containing
material, wherein the fine filler particles comprise a carbon-based
material, wherein the fine filler particles comprise graphite,
wherein the fine filler particles consist essentially of
graphite.
[0049] Item 5. The abrasive article of any of items 1 and 2,
wherein the coarse filler particles comprise an inorganic material,
wherein the coarse filler particles comprise a carbon-containing
material, wherein the coarse filler particles comprise a
carbon-based material, wherein the coarse filler particles comprise
graphite, wherein the coarse filler particles consist essentially
of graphite.
[0050] Item 6. The abrasive article of any of items 1 and 2,
wherein the fine filler particles and the coarse filler particles
comprise a same element, wherein the fine filler particles and the
coarse filler particles comprise a same carbon-containing material,
wherein the fine filler particles and coarse filler particles
comprise a same carbon-based material, wherein the fine filler
particles and the coarse filler particles comprise graphite,
wherein the fine filler particles and the coarse filler particles
consist essentially of the same material.
[0051] Item 7. The abrasive article of any of items 1 and 2,
wherein fine filler particles comprise an average particle size of
not greater than about 120 microns, and at least about 5
microns.
[0052] Item 8. The abrasive article of any of items 1 and 2,
wherein coarse filler particles comprise an average particle size
of not greater than about 200 microns, and at least about 15
microns.
[0053] Item 9. The abrasive article of item 2, further comprising a
filler particle size ratio (Ff/Fc) of not greater than about 0.97,
wherein the Ff represents the average particle of the fine filler
particles and Fc represents the average particle size of the coarse
filler particles.
[0054] Item 10. The abrasive article of any of items 1 and 29,
wherein the filler particle size ratio (Ff/Fc) is not greater than
about 0.95, not greater than about 0.93, not greater than about
0.9, not greater than about 0.88, not greater than about 0.85, not
greater than about 0.83, not greater than about 0.8, not greater
than about 0.78, not greater than about 0.75, not greater than
about 0.73, not greater than about 0.7, not greater than about
0.68, not greater than about 0.65, not greater than about 0.63, not
greater than about 0.6, not greater than about 0.58, not greater
than about 0.55, not greater than about 0.53, not greater than
about 0.5, not greater than about 0.48, not greater than about
0.45, not greater than about 0.43, not greater than about 0.4, not
greater than about 0.3, not greater than about 0.2, not greater
than about 0.1.
[0055] Item 11. The abrasive article of any of items 1 and 9,
wherein the filler particle size ratio (Ff/Fc) is at least about
0.03, at least about 0.05, at least about 0.08, at least about 0.1,
at least about 0.13, at least about 0.15, at least about 0.18, at
least about 0.2, at least about 0.23, at least about 0.25, at least
about 0.28, at least about 0.3, at least about 0.33, at least about
0.35, at least about 0.38, at least about 0.4, at least about 0.43,
at least about 0.45, at least about 0.48, at least about 0.5, at
least about 0.53, at least about 0.55, at least about 0.58, at
least about 0.6, at least about 0.63, at least about 0.65, at least
about 0.68, at least about 0.7, at least about 0.73, at least about
0.75, at least about 0.78, at least about 0.8, at least about
0.9.
[0056] Item 12. The abrasive article of any of items 1 and 2,
wherein the filler blend comprises a filler content ratio (Cf/Cc)
of at least about 0.05, wherein Cf represents the volume percent of
fine filler particles for the total volume of the bonded abrasive
body and Cc represents the volume percent of the coarse filler
particles for the total volume of the bonded abrasive body, wherein
the filler content ratio is at least about 0.1, at least about 0.2,
at least about 0.3, at least about 0.4, at least about 0.5, at
least about 0.6, at least about 0.7, at least about 0.8, at least
about 0.9, at least about 1, at least about 1.1, at least about
1.2, at least about 1.3, at least about 1.4, at least about
1.5.
[0057] Item 13. The abrasive article of any of items 1 and 2,
wherein the filler blend comprises a filler content ratio (Cf/Cc)
of not greater than about 10, wherein Cf represents the volume
percent of fine filler particles for the total volume of the bonded
abrasive body and Cc represents the volume percent of the coarse
filler particles for the total volume of the bonded abrasive body,
wherein the filler content ratio is not greater than about 9, not
greater than about 8, not greater than about 7, not greater than
about 6, not greater than about 5, not greater than about 4, not
greater than about 3, not greater than about 2, not greater than
about 1, not greater than about 0.95, not greater than about 0.9,
not greater than about 0.8, not greater than about 0.7, not greater
than about 0.6, not greater than about 0.5, not greater than about
0.4, not greater than about 0.3, not greater than about 0.2, not
greater than about 0.1.
[0058] Item 14. The abrasive article of any of items 1 and 2,
wherein the bonded abrasive body comprises at least about 1 vol %
of the filler blend for the total volume of the bonded abrasive
body, at least about 3 vol %, at least about 5 vol %, at least
about 8 vol %, at least about 10 vol %, at least about 13 vol %, at
least about 15 vol %, at least about 18 vol %.
[0059] Item 15. The abrasive article of any of items 1 and 2,
wherein the bonded abrasive body comprises not greater than about
50 vol % of the filler blend for the total volume of the bonded
abrasive body, not greater than about 45 vol %, not greater than
about 40 vol %, not greater than about 35 vol %, not greater than
about 30 vol %, not greater than about 28 vol %, not greater than
about 25 vol %, not greater than about 22 vol %.
[0060] Item 16. The abrasive article of any of items 1 and 2,
wherein the bonded abrasive body comprises at least about 1 vol %
of the fine filler particles for the total volume of the bonded
abrasive body, at least about 2 vol %, at least about 3 vol %, at
least about 4 vol %, at least about 5 vol %, at least about 6 vol
%, at least about 7 vol %, at least about 8 vol %.
[0061] Item 17. The abrasive article of any of items 1 and 2,
wherein the bonded abrasive body comprises not greater than about
25 vol % of the fine filler particles for the total volume of the
bonded abrasive body, not greater than about 22 vol %, not greater
than about 20 vol %, not greater than about 18 vol %, not greater
than about 16 vol %, not greater than about 13 vol %, not greater
than about 10 vol %.
[0062] Item 18. The abrasive article of any of items 1 and 2,
wherein the bonded abrasive body comprises at least about 1 vol %
of the coarse filler particles for the total volume of the bonded
abrasive body, at least about 2 vol %, at least about 3 vol %, at
least about 4 vol% , at least about 5 vol %, at least about 6 vol
%, at least about 7 vol %, at least about 8 vol %.
[0063] Item 19. The abrasive article of any of items 1 and 2,
wherein the bonded abrasive body comprises not greater than about
25 vol % of the coarse filler particles for the total volume of the
bonded abrasive body, not greater than about 22 vol %, not greater
than about 20 vol %, not greater than about 18 vol %, not greater
than about 16 vol %, not greater than about 13 vol %, not greater
than about 10 vol %.
[0064] Item 20. The abrasive article of any of items 1 and 2,
wherein the bonded abrasive body comprises not greater than about
85 vol % of the abrasive particles for the total volume of the
bonded abrasive body, not greater than about 82 vol %, not greater
than about 80 vol %, not greater than about 75 vol %, not greater
than about 70 vol %, not greater than about 65 vol %, not greater
than about 60 vol %.
[0065] Item 21. The abrasive article of any of items 1 and 2,
wherein the bonded abrasive body comprises at least about 10 vol %
of the abrasive particles for the total volume of the bonded
abrasive body, at least about 15 vol %, at least about 20 vol %, at
least about 25 vol %, at least about 30 vol %, at least about 35
vol %, at least about 40 vol %, at least about 45 vol %.
[0066] Item 22. The abrasive article of any of items 1 and 2,
wherein the abrasive particles comprise an average particle size of
not greater than about 200 microns, not greater than about 180
microns, not greater than about 150 microns, not greater than about
130 microns, not greater than about 110 microns, not greater than
about 100 microns, not greater than about 80 microns, not greater
than about 70 microns, not greater than about 65 microns, not
greater than about 60 microns, not greater than about 55 microns,
not greater than about 50 microns, not greater than about 45
microns.
[0067] Item 23. The abrasive article of any of items 1 and 2,
wherein the abrasive particles comprise an average particle size of
at least about 0.5 microns, at least about 1 micron, at least about
2 microns, at least about 5 microns, at least about 8 microns, at
least about 10 microns, at least about 15 microns, at least about
20 microns, at least about 25 microns, at least about 30
microns.
[0068] Item 24. The abrasive article of any of items 1 and 2,
wherein the abrasive particles have a hardness greater than the
fine filler particle, wherein the abrasive particles have a
hardness greater than the coarse filler particle, wherein the
abrasive particles have a Mohs hardness of at least about 7, at
least about 8, at least about 9.
[0069] Item 25. The abrasive article of any of items 1 and 2,
wherein the abrasive particles comprise an inorganic material,
wherein the abrasive particles comprise a naturally occurring
material, wherein the abrasive particles comprise a synthesized
material, wherein the abrasive particles comprise a material
selected from the group consisting of oxides, carbides, nitrides,
borides, oxycarbides, oxynitrides, oxyborides, carbon-containing
materials, diamond, and a combination thereof.
[0070] Item 26. The abrasive article of any of items 1 and 2,
wherein the abrasive particles comprise a superabrasive material,
wherein the abrasive particles comprise a diamond, wherein the
abrasive particles comprise cubic boron nitride, wherein the
abrasive particles consist essentially of diamond, wherein the
abrasive particles comprise having a content of polycrystalline
diamond.
[0071] Item 27. The abrasive article of any of items 1 and 2,
wherein the bond material comprises a transition metal element,
wherein the bond material comprises a transition metal element
selected from the group consisting of copper, tin, silver, nickel,
and a combination thereof.
[0072] Item 28. The abrasive article of any of items 1 and 2,
wherein the bond material comprises bronze including copper (Cu)
and tin (Sn), wherein the bronze comprises a content of copper that
is not less than a content of tin, wherein the bronze comprises a
content of copper that is greater than a content of tin, wherein
the bronze comprises a copper/tin ratio (Cu/Sn) of at least about
0.2, at least about 0.23, at least about 0.25, at least about 0.28,
at least about 0.3, at least about 0.33, at least about 0.35, at
least about 0.38, at least about 0.4, at least about 0.43, at least
about 0.45, at least about 0.48, at least about 0.5, at least about
0.53, at least about 0.55, at least about 0.58, at least about 0.6,
at least about 0.63, at least about 0.65, at least about 0.68, at
least about 0.7, at least about 0.73, at least about 0.75, at least
about 0.78, at least about 0.8, at least about 0.9.
[0073] Item 29. The abrasive article of any of items 1 and 2,
wherein the bond material comprises bronze including copper (Cu)
and tin (Sn), wherein the bronze comprises a copper/tin ratio
(Cu/Sn) of not greater than about 0.93, not greater than about 0.9,
not greater than about 0.88, not greater than about 0.85, not
greater than about 0.83, not greater than about 0.8, not greater
than about 0.78, not greater than about 0.75, not greater than
about 0.73, not greater than about 0.7, not greater than about
0.68, not greater than about 0.65, not greater than about 0.63, not
greater than about 0.6, not greater than about 0.58, not greater
than about 0.55, not greater than about 0.53, not greater than
about 0.5, not greater than about 0.48, not greater than about
0.45, not greater than about 0.43, not greater than about 0.4, not
greater than about 0.3, not greater than about 0.2.
[0074] Item 30. The abrasive article of any of items 1 and 2,
wherein the bonded abrasive body comprises at least about 10 vol %
of the bond material for the total volume of the bonded abrasive
body, at least about 15 vol %, at least about 20 vol %, at least
about 25 vol %, at least about 30 vol %, at least about 35 vol %,
at least about 40 vol %, at least about 45 vol %. [target is
between 50-80]
[0075] Item 31. The abrasive article of any of items 1 and 2,
wherein the bonded abrasive body comprises not greater than about
85 vol % of the bond material for the total volume of the bonded
abrasive body, not greater than about 82 vol %, not greater than
about 80 vol %, not greater than about 75 vol %, not greater than
about 70 vol %, not greater than about 65 vol %.
EXAMPLE 1
[0076] Two samples were formed for comparative testing. A first
sample, CS1, represents a conventional sample formed form a mixture
including 4.8 wt % diamond abrasive particles, 89.4 wt %
pre-alloyed bronze (copper/tin ratio of 1) metal bond material, and
5.8 wt % graphite filler material having an average particle size
of approximately 125 microns. Sample CS1 was molded into a green
article, hot pressed at a temperature of approximately 375.degree.
C. to about 700.degree. C. at a pressure from about 0.5
tons/in.sup.2 to 4 tons/in.sup.2 to form a bonded abrasive body
having about 5 vol % diamond abrasive particles, 20 vol % graphite
filler material, and about 75 vol % bronze bond material.
[0077] The second sample, S2, represents a sample of an embodiment,
and is formed form a mixture including 19.5 wt % diamond abrasive
particles, 75.6 wt % pre-alloyed bronze (copper/tin ratio of 1)
metal bond material, and 4.8 wt % of a filler blend including 2.4
wt % of graphite fine filler particles having an average particle
size of about 15 microns, and 2.4 wt % of graphite coarse filler
particles having an average particle size of about 125 microns.
Sample S2 was formed into a bonded abrasive body using essentially
the same process as used to form sample CS1. Sample S2 had 19 vol %
diamond abrasive particles, 20 vol % graphite filler blend
including 10 vol % fine filler particles and 10 vol % coarse filler
particles, and approximately 51 vol % bronze bond material.
[0078] Samples CS1 and S2 were used in a backgrinding operation of
c-plane sapphire substrates according to the following
conditions.
[0079] FIG. 1 includes a plot of cumulative wheel wear of the
bonded abrasive body in microns versus cumulative material removed
from the workpiece in microns. As illustrated, sample S2
demonstrated significantly less wheel wear as compared to sample
CS1 over a greater range of cumulative material removed. That is,
Sample CS 1 demonstrated significantly less total material removed
as compared to sample S2 and also demonstrated significantly
greater wear for the limited amount of material removed.
[0080] FIG. 2 includes a plot of percent maximum power versus time
for the backgrinding operation. As illustrated in FIG. 2, sample
CS2 demonstrated regular spikes in the percentage maximum power
utilized, indicated regimes of inefficient grinding and high forces
on the bonded abrasive body during the backgrinding operation. By
contrast, sample S2, demonstrated no significant localized spikes
during the backgrinding operation and thus demonstrated
significantly more uniform and efficient grinding throughout the
use of the bonded abrasive body as compared to sample CS1.
[0081] 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.
[0082] The Abstract of the Disclosure 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 of the Drawings,
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 of the Drawings, with
each claim standing on its own as defining separately claimed
subject matter.
* * * * *