U.S. patent application number 11/090317 was filed with the patent office on 2006-02-16 for solid state processing of industrial blades, edges and cutting elements.
Invention is credited to Richard A. Flak, Scott M. Packer, Hobie Smith, Russell J. Steel.
Application Number | 20060032333 11/090317 |
Document ID | / |
Family ID | 35064256 |
Filed Date | 2006-02-16 |
United States Patent
Application |
20060032333 |
Kind Code |
A1 |
Steel; Russell J. ; et
al. |
February 16, 2006 |
Solid state processing of industrial blades, edges and cutting
elements
Abstract
A system and method for friction stir processing of an
industrial blade, wherein friction stir processing techniques are
used to modify the properties of the industrial blade to thereby
obtain superior edge retention and superior resistance to
chipping.
Inventors: |
Steel; Russell J.; (Salem,
UT) ; Packer; Scott M.; (Alpine, UT) ; Flak;
Richard A.; (Provo, UT) ; Smith; Hobie;
(Houston, TX) |
Correspondence
Address: |
MORRISS O'BRYANT COMPAGNI, P.C.
136 SOUTH MAIN STREET
SUITE 700
SALT LAKE CITY
UT
84101
US
|
Family ID: |
35064256 |
Appl. No.: |
11/090317 |
Filed: |
March 24, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60556050 |
Mar 24, 2004 |
|
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|
60573707 |
May 21, 2004 |
|
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60637223 |
Dec 17, 2004 |
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60654608 |
Feb 18, 2005 |
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Current U.S.
Class: |
76/37 |
Current CPC
Class: |
B23D 63/12 20130101;
C21D 9/18 20130101; C22F 1/00 20130101; B23P 15/28 20130101; B23K
20/1225 20130101; B23K 20/1275 20130101; C23C 26/00 20130101; B23P
15/40 20130101 |
Class at
Publication: |
076/037 |
International
Class: |
B23D 63/12 20060101
B23D063/12 |
Claims
1. A method for creating an industrial blade, said method
comprising the steps of: 1) providing a high melting temperature
workpiece that is to be formed into an industrial blade; 2)
providing a friction stir processing tool that includes a higher
melting temperature material than the workpiece on a portion
thereof; and 3) friction stir processing the workpiece using the
tool to thereby modify characteristics thereof; and 4) forming the
industrial blade from the workpiece.
2. The method as defined in claim 1 wherein the method further
comprises the step of causing a substantially solid state
transformation without passing though a liquid state of the
workpiece.
3. The method as defined in claim 1 wherein the step of providing
the high melting temperature workpiece includes selecting the high
melting temperature workpiece from the group of high melting
temperature materials including ferrous alloys, non-ferrous
materials, superalloys, titanium, cobalt alloys typically used for
hard-facing, and air hardened or high speed steels.
4. The method as defined in claim 1 wherein the method further
comprises the step of synthesizing a new material from solid state
processing of the workpiece, wherein the new material has
characteristics that are advantageous to an industrial blade.
5. The method as defined in claim 1 wherein the method further
comprises the steps of: 1) providing an additive material; and 2)
friction stir mixing an additive material into the workpiece to
thereby modify at least one characteristic of the workpiece.
6. The method as defined in claim 1 wherein the method further
comprises the step of modifying a microstructure of the
workpiece.
7. The method as defined in claim 6 wherein the method further
comprises the step of modifying a macrostructure of the
workpiece.
8. The method as defined in claim 7 wherein the step of modifying
the microstructure includes increasing toughness of the
workpiece.
9. The method as defined in claim 7 wherein the step of modifying
the microstructure includes increasing or decreasing hardness of
the workpiece.
10. The method as defined in claim 7 wherein the step of modifying
the microstructure includes increasing or decreasing strength of
the workpiece.
11. The method as defined in claim 7 wherein the step of modifying
the microstructure includes friction stir processing the workpiece
to thereby obtain superior edge retention on the industrial blade
that is formed therefrom.
12. The method as defined in claim 7 wherein the step of modifying
the microstructure includes friction stir processing the workpiece
to thereby obtain superior resistance to chipping on the industrial
blade that is formed therefrom.
13. The method as defined in claim 1 wherein the step of providing
the friction stir processing tool further includes the step of
providing the friction stir processing tool having a shank, a
shoulder and a pin.
14. The method as defined in claim 13 wherein the step of providing
the friction stir processing tool having a shank, a shoulder and a
pin further comprises the step of including a superabrasive
material.
15. The method as defined in claim 15 wherein the method further
comprises the step of friction stir processing without plunging the
pin into the workpiece.
16. The method as defined in claim 1 wherein the step of providing
the friction stir processing tool further includes the step of
providing the friction stir processing tool having a shank and a
shoulder.
17. A hand-held knife with a blade having improved edge retention
and resistance to chipping, said industrial blade comprised of a
high melting temperature workpiece, wherein the high melting
temperature workpiece is created through friction stir
processing.
18. A system for manufacturing a hand-held knife blade through
friction stir processing, said system comprised of: a high melting
temperature workpiece; and a friction stir processing tool that
includes a higher melting temperature material than the workpiece
on a portion thereof, wherein the tool is used to perform friction
stir processing to thereby cause solid state transformation of the
workpiece, wherein characteristics of the workpiece are
modified.
19. The system as defined in claim 18 wherein the tool is further
comprised of a shank, a shoulder and a pin.
20. The system as defined in claim 18 wherein the tool is further
comprised of a shank and a shoulder.
Description
CROSS REFERENCE TO RELATED APPLICATIONS
[0001] This document claims priority to and incorporates by
reference all of the subject matter included in the provisional
patent applications having docket number 2992.SMII.PR with Ser. No.
60/556,050 and filed Mar. 24, 2004, docket number 3043.SMII.PR with
Ser. No. 60/573,707 and filed May 21, 2004, docket number
3208.SMII.PR with Ser. No. 60/637,223 and filed Dec. 17, 2004, and
docket number 3212.SMII.PR with Ser. No. 60/654,608 and filed Feb.
18, 2005.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] This invention relates generally to industrial blades. More
specifically, the invention relates to a method for improving
characteristics of industrial blades, edges and cutting
elements.
[0004] 2. Description of Related Art
[0005] It should be understood that the present invention applies
to any type of industrial blade, edge, or cutting elements where
sharpness, the ability to remain sharp, and resistance to chipping
are important features. Hereinafter, the terms "edge" and "cutting
element" are to be considered included in the term "industrial
blade."
[0006] Sharpness and the ability to retain a sharp edge are just
two important criteria for an industrial blade. It is often the
case that industrial blades are smaller components of much larger
systems. Other industrial blades are cutters, borers, milling
blades, drill bits, openers, groovers, crushers, reamers, saw
blades and knives of various sorts that are used to perform various
industrial applications in many different industries. Regardless of
the industry, an industrial blade that can remain sharp and resist
chipping for longer periods of time results in substantial time and
cost benefits.
[0007] It is noted that impact resistance and toughness is
inversely related to wear resistance and hardness for most
industrial blade materials. Therefore, different industrial blades
are typically required for impact applications and sharpness
applications.
[0008] Certain industrial blades have been specifically designed to
withstand the impact of cutting hard material without the edge
chipping. Generally, increased impact toughness means lower RC
hardness as compared to the higher RC values of other industrial
blades. As a result, the ability to maintain a sharp edge (referred
to hereinafter as edge retention) is compromised. A technique has
been developed to test several different types of steel at
different "Rockwell" or RC hardness measurements until a happy
medium is found between "good" edge retention, where there is no
dulling of the industrial blade, and the prevention of edge
chipping.
[0009] When examining industrial blades, it is useful to examine
analogous blades in the hand-held blade industry. For example, a
conventional D2 steel hand-held cleaver, such as a Brown Bear.TM.
Cleaver, is designed to consistently cut through bone without
chipping. However, when a rope is repeatedly cut with the hand-held
cleaver, the edge retention is typically not up to par with harder
hand-held knife blades, such as a Jaeger.TM. Boning knife also sold
by Knives of Alaska. Similarly, harder hand-held knife blades that
offer increased edge retention in low impact cutting applications
typically experience edge chipping when used to cut or chop through
harder material such as hard wood and bone due to the increased
brittleness of the hand-held blade.
[0010] Ideally, an industrial blade, like a hand-held blade, would
be able to withstand abrasive cutting and retain a sharp edge, yet
be able to withstand the high impact necessary to chop through hard
materials without the edge chipping or fracturing.
[0011] Accordingly, what is desired is an industrial blade that can
withstand the high impact of chopping or cutting through hard
materials, and still provide superior edge retention.
BRIEF SUMMARY OF THE INVENTION
[0012] In one aspect, the present invention provides a method for
enhancing the mechanical properties of an industrial blade.
[0013] In another aspect the present invention provides an
industrial blade having superior edge retention and a method for
forming the same.
[0014] In another aspect, the invention provides a method for
forming a cutting edge on an industrial blade that will result in
superior resistance to chipping.
[0015] In one embodiment, the present invention provides a system
and method for friction stir processing of an industrial blade,
wherein friction stir processing techniques are used to modify the
properties of the industrial blade to thereby obtain superior edge
retention and superior resistance to chipping.
[0016] These and other aspects, features, advantages of the
embodiments of the present invention will become apparent to those
skilled in the art from a consideration of the following detailed
description taken in combination with the accompanying
drawings.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWINGS
[0017] FIG. 1 is a perspective view of one tool that can be used to
perform the friction stir processing of the present invention.
[0018] FIG. 2 is a cross-sectional view of another tool that can be
used to perform the friction stir processing of the present
invention.
[0019] FIG. 3 is a cross-sectional view of another tool that can be
used to perform the friction stir processing of the present
invention.
[0020] FIG. 4 is a cross-sectional view of a material that is
friction stir processed to modify the characteristics of the
material.
[0021] FIG. 5 is a cross-sectional view of a material that is
friction stir processed to modify the characteristics of the
material, and having an overlay identifying where a cutting edge
could be formed from the friction stir processed material.
[0022] FIG. 6 is a cross-sectional view of material that has been
friction stir mixed so as to include another material.
[0023] FIG. 7 is a cross-sectional view of one embodiment for
friction stir mixing an additive material 112 into another using a
mesh or screen 110 to hold the additive material 112 in place.
[0024] FIGS. 8-66 are various industrial blades.
DETAILED DESCRIPTION OF THE INVENTION
[0025] Reference will now be made to the diagrams of the present
invention in which the various elements of the present invention
will be given numerical designations and in which the invention
will be discussed so as to enable one skilled in the art to make
and use the invention. It is to be understood that the following
description is only exemplary of the principles of the present
invention, and should not be viewed as narrowing the claims which
follow.
[0026] In one aspect, the present invention provides a system and
method for performing friction stir processing on an industrial
blade. The friction stir processing can be performed in one
embodiment on a surface of a workpiece that is fashioned into the
industrial blade. In another embodiment, the friction stir
processing can be performed deeper into the workpiece. In another
embodiment, it is also possible to perform friction stir mixing
wherein an additive element is mixed into the surface or deeper
into a workpiece using a friction stir mixing tool.
[0027] FIG. 1 is a perspective view of a tool being used for
friction stir welding that is characterized by a generally
cylindrical tool 10 having a shoulder 12 and a pin 14 extending
outward from the shoulder. The pin 14 is rotated against a
workpiece 16 until sufficient heat is generated, at which point the
pin of the tool is plunged into the plasticized workpiece material.
The workpiece 16 is often two sheets or plates of material that are
butted together at a joint line 18. The pin 14 is plunged into the
workpiece 16 at the joint line 18. Although this tool has been
disclosed in the prior art, it will be explained that the tool can
be used for a new purpose.
[0028] Another embodiment of the present invention is to use a tool
as shown in FIG. 2. FIG. 2 is a cross-sectional view of a
cylindrical friction stir processing tool 20. The friction stir
processing tool 20 has a shank 22 and a shoulder 24, but no pin.
Therefore, instead of plunging a pin into the material to be solid
state processed, the shoulder is pressed against the material.
Penetration by the shoulder is typically going to be restricted to
the surface of the material or just below it because of the larger
surface area of the shoulder as compared to the pin.
[0029] It should be noted that while the pin 16 of the tool 10 in
FIG. 1 does not have to be plunged into the material, the pin is
more likely to be designed for easy penetration. Thus, because the
pin 16 is more likely to have a very small surface area as compared
to the tool 20 of FIG. 2, the pin is more likely to plunge into the
material. However, it may be advantageous to use the smaller
surface area of the pin 16 for processing much smaller areas of a
material, even just on the surface thereof. Therefore, it is
another embodiment of the present invention that surface and
near-surface processing can also be accomplished using a tool that
is more typically used for penetration and joining of
materials.
[0030] FIG. 3 is provided as an alternative embodiment for a tool
having no pin. FIG. 3 shows a tool 30 having a shank 32 that is
smaller in diameter than the shoulder 34. This design can be more
economical because of less material used in its construction,
depending upon the diameter of the shoulder 34.
[0031] It is important to recognize that nothing should be inferred
from the shape of the shoulders 24 and 34 in FIGS. 2 and 3. The
shoulders 24 and 34 are shown for illustration purposes only, and
their exact cross-sectional shapes can be modified to achieve
specific results.
[0032] Experimental results have demonstrated that the material to
be used for the industrial blade may undergo several important
changes during friction stir processing. These changes may include,
but should not be considered limited to, the following:
microstructure, macrostructure, toughness, hardness, grain
boundaries, grain size, the distribution of phases, ductility,
superplasticity, change in nucleation site densities,
compressibility, expandability, coefficient of friction, abrasion
resistance, corrosion resistance, fatigue resistance, magnetic
properties, strength, radiation absorption, and thermal
conductivity.
[0033] Regarding nucleation, observations indicate that there may
be more nucleation sites in the processed material due to the
energy induced into the material from friction stir processing.
Accordingly, more of the solute material may be able to come out of
solution or precipitate to form higher densities of precipitates or
second phases.
[0034] In FIG. 4, a section of ATS 34 steel was friction stir
processed by plunging a tool similar to the tool shown in FIG. 2
into the workpiece 70 and moving the tool transversely along a
middle length thereof. Transverse movement would be perpendicular
to the page, thus FIG. 5 is a cross-sectional view of the base
material 70.
[0035] FIG. 4 shows that the tool plunged into the base material 70
from the top 72. Several areas appearing as small circles are shown
as having been tested for hardness relative to the Rockwell scale
in the various zones of the base material. The stir zone 74 is
shown having a hardness of 60 RC. Close to the boundary of the
inner TMAZ (thermally mechanically affected zone) and the outer HAZ
(heat affected zone) the base material 70 is shown as having a
hardness value of 44 RC at a location 76. Finally, an unprocessed
or original base material zone is shown as having retained, in
other samples, its original hardness value of 12 RC at
approximately location 78.
[0036] FIG. 5 is an illustration of an overlay 90 of a cutting edge
on the ATS-34 steel base material 70. The overlay 90 indicates one
advantageous configuration of an industrial blade that could be
machined from the material 70, wherein the configuration takes the
greatest advantage of the improved toughness and hardness
characteristics of the friction stir processed material 70. Note
that the industrial blade overlay 90 is formed in the processed
region 74 that will result in a hard and yet tough cutting edge.
Likewise, any object being formed from a processed material can be
arranged to provide the most advantageous properties where it is
most critical for the object. In this example, a beneficial cutting
edge will be achieved from having an edge disposed well within the
processed material.
[0037] As examples of what is possible to create using the system
and methods of the embodiments of the present invention, three
hand-held blades processed using a friction stir processing system
and method in accordance with the present invention were prepared
and tested against conventional blades. The creation of the test
blades was accomplished by friction stir processing a workpiece
that was then finished to form a hand-held knife blade having a
profile substantially identical to a conventional knife blade used
for a comparison.
[0038] The hand-held test blades of the present invention were
created by machining the hand-held test blades in accordance with
the following instructions. The first attempt at grinding was to
obtain a 22 degree angle with a 600 grit diamond belt. The result
was a polished edge. A 320 diamond grit was then used with good
results to further refine the hand-held blade. The desired angle
was established and after a few passes, the cutting edge was placed
against the 600 grit diamond belt to establish the desired wire
"burr". The wire burr was removed with an 8,000 grit diamond belt
and then polished with a 50,000 grit diamond belt. A razor
"shaving" edge was established on the test blades and the cutting
edge appeared to remain totally within the processed material.
[0039] It should be noted that the instructions provided above are
only to create test blades that are comparable in sharpness to the
blades that are being used for comparison purposes. An industrial
blade that can be created using the friction stir processing and
friction stir mixing methods of the present invention should not be
considered to be limited to the parameters stated above.
[0040] An important element of the present invention is also the
concept of friction stir mixing. Whereas friction stir processing
will be regarding as the processing of a single material that is to
be fashioned into an industrial blade, friction stir mixing
provides for additional additive materials to be included in the
friction stir mixing process. The additive materials become an
integral part of the resulting industrial blades.
[0041] FIG. 6 is a cross-sectional view of a base material that has
been friction stir mixed so as to include another additive
material. Specifically, a steel member 100 has been friction stir
mixed so as to work in diamond particles 102 into the steel
member.
[0042] FIG. 7 is a cross-sectional view of one embodiment for
friction stir mixing an additive material 112 into another using a
mesh or screen 110 to hold the additive material 112 in place.
Specifically, a stainless steel mesh or screen 110 is being used to
hold carbide 112 in the form of a powder. The screen 110 and
carbide powder 112 are disposed on the surface of a base material
114. The surface of the base material 114 is then friction stir
processed, resulting in a mixing of the stainless steel 110, the
carbide 112, and the base material 114 at the surface of the base
material. Alternatively, the different materials could be mixed
further into the base material 114 using a tool having a pin, or by
using a tool having a shoulder that is pressed harder into the base
material.
[0043] An important concept of the present invention is that solid
state processing or friction stir processing that is performed is a
temporary transformation into a plasticized state. Thus, the
material that is used as the workpiece and formed into the
industrial blade may not pass through a liquid state.
[0044] The balance of this document is devoted to test results for
comparisons that achieved unexpected results using hand-held
blades. For comparison purposes, a Brown Bear.TM. hand-held Cleaver
blade formed of D-2 steel was bolted to a test handle. A hand-held
test blade having a cutting edge formed of friction stir processed
D-2 steel ground to an identical profile was also prepared and
bolted to a handle in a similar manner. The resulting hand-held
cleaver blade and hand-held test blade were both 24 ounce blades
that provided ample weight and inertia for chopping.
[0045] A first chopping test was performed on a green red oak limb;
a second chopping test was performed on a dried Osage orange limb,
which is an extremely hard, dense wood; a third chopping test was
performed on an elk antler (bone); a fourth chopping test was
performed on a brick block, and a fifth chopping test was performed
on a steel anvil. Results for chopping with the test blade are as
follows in Table 1: TABLE-US-00001 TABLE 1 Test Result Green red
oak No edge chipping; edge will still shave dry hair Dried Osage No
edge chipping; edge will still Orange shave dry hair Elk antler No
edge chipping; minor edge wear evident; would shave wet hair Brick
Edge damage evident with several small chips and dulled edge Steel
anvil Small edge separation at point of machining groove for
friction stir
[0046] Both hand-held cleavers were able to consistently cut
through bone and hard wood without chipping. However, the hand-held
test blade was found to provide greater edge retention over the
conventional hand-held cleaver.
[0047] The above tests were also performed using a hand-held
Bush.TM. Camp Knife and a hand-held Jaeger.TM. Boning knife which
both have good edge retention when compared to other hand-held
knives. As shown in FIG. 16, both hand-held knives had catastrophic
cutting edge failures when tested on the elk antler and, thus, were
not tested on the harder materials.
[0048] A second hand-held test blade was sharpened to perform new
tests. The second test blade was used to cut rope for 30 minutes.
In that time, 607 cuts were made until the rope was gone. The
second hand-held test blade still shaved dry hair afterwards.
[0049] Further tests were performed on hand-held test blades, such
as the sharpness test of the friction stir processed edge. For this
test, five different Knives of Alaska.TM., Inc. hand-held knife
models were first tested. These hand-held knives include the
Alaskan Brown Bear Skinner/Cleaver (D2 steel; RC 55-57), the Jaeger
Boning Knife (ATS-34 steel; RC 59-61), the Bush Camp Knife (AUS8
steel; RC 57-59), the Coho fisherman's knife (hollow ground AUS8
steel; RC 57-59), and the Magnum Ulu (D2 steel; RC 59-61). The
final test was on a hand-held test blade with the friction stir
processed edge.
[0050] The test for sharpness involved placing a 3/4 inch thick
hemp rope on a 2.times.6 board. A section on each knife was
selected and the rope was cut completely through by striking the
back of the blade with a soft mallet. The rope was repeatedly cut,
at the same point on the hand-held knife blade. The number of cuts
was recorded for each hand-held blade. When the hand-held knife's
tested section would no longer shave dry hair on the tester's
arm--this was recorded as one past the maximum number of cuts that
that hand-held blade steel would retain a shaving edge. The test
results are as follows as shown in Table 2: TABLE-US-00002 TABLE 2
Number of Cuts Where hand-held Hand-held Knife Knife No Longer
Shaves Alaskan Brown Bear 17 Jaeger Boning Knife 67 Bush Camp Knife
41 Coho Fisherman's Knife 14 Magnum Ulu 52 Test Blade 100+
[0051] It is observed that the testing of the hand-held test blade
was stopped at 100 cuts as the hand-held test blade was already
exceeding all other test samples. The hand-held test blade is shown
in FIG. 15. Furthermore, the hand-held blade would still shave and
there was no appreciable difference between the edge when the
testing began and after 100 cuts.
[0052] The test blades formed in accordance with the present
invention held up to and exceeded expectations in the sharpness
category and in the impact test results. Conventionally, it is
unexpected to be able to take a two pound hand-held test blade and
swing it smartly to cut through a hard material such as elk antler,
repeatedly, and still retain a shaving edge with no edge
fracturing. Such performance is unheard of in the hand-held knife
industry.
[0053] Friction stir processing may be applied to any hand-held
knife blade to enhance performance characteristics of the blades.
Such hand-held knife blades may be formed of any material known in
the art, including D2 steel, ATS-34 steel, AUS8 steel, S-30V steel,
or other materials.
[0054] FIGS. 8-66 are provided as illustrations of the many
different types of industrial blades that are considered to be
within the scope of the embodiments of the present invention.
However, the following list of industrial blades should not be
considered limiting, as there are other industrial blades that can
also take advantage of the benefits of the embodiments of the
present invention.
[0055] FIGS. 8-66 includes the following industrial blades: angle
milling cutter, boring tools, broach, burr, chanfer cutter,
circular cutting blades for food, metal or paper, converting
slitters, counter bores, counter sinks, cutting tool endmill,
cutting tool reamer, deburring tool, drill bit, endmill, fishing
milling cutter, food processing, form cutter, gear cutting tool,
gear shaper tool-shaving cutter, grooving tool, guillotine paper
and food cutting blades, gun drill and reamers, helical end mill,
hobs, hobs and side milling cutters, hole opener, hole saw,
hydraulic pipe cutter, jaw crusher, keyseat cutter, metal working
shear blades, milling cutter, packaging and cutoff knives, plastic
granulating knives, press brake dies, reamer, rotaryfile cutter,
round textile knife, router bit, saw blades, shear blades, shell
end mills, side milling cutter, slitter blades for packaging, tap
cutter, taps, textile knives, thin disk cutters, thread mill, and
threading tool. This list of industrial blades should not be
considered limiting, but presents a large cross-section of the
various industrial blades on the market.
[0056] It is to be understood that the above-described arrangements
are only illustrative of the application of the principles of the
present invention. Numerous modifications and alternative
arrangements may be devised by those skilled in the art without
departing from the spirit and scope of the present invention. The
appended claims are intended to cover such modifications and
arrangements.
* * * * *