U.S. patent application number 09/253581 was filed with the patent office on 2001-11-08 for method for forming a superabrasive polycrystalline cutting tool with an integral chipbreaker feature.
Invention is credited to JENSEN, KENNETH M., MIESS, DAVID, POPE, BILL J..
Application Number | 20010037609 09/253581 |
Document ID | / |
Family ID | 22960876 |
Filed Date | 2001-11-08 |
United States Patent
Application |
20010037609 |
Kind Code |
A1 |
JENSEN, KENNETH M. ; et
al. |
November 8, 2001 |
METHOD FOR FORMING A SUPERABRASIVE POLYCRYSTALLINE CUTTING TOOL
WITH AN INTEGRAL CHIPBREAKER FEATURE
Abstract
A method or process for making polycrystalline diamond or
polycrystalline CBN cutting tools (Superabrasives), which have
integral chip-breaking features is disclosed. This method involves
pressing a die or other like rigid component against either the
outer can cover or the diamond or CBN region directly. This
invention provides economical manufacture of diamond chip-breaker
tools, while avoiding unnecessary EDM EDG, grinding, or laser
processes. This process forms the chip-breaker on the upper surface
of the diamond region, during or prior to sintering. This invention
permits a wide variety of chip-breaker or other diamond surface
features, while minimizing cost and processing steps. Disclosed
embodiments include: pressing through the can assembly; pressing
within the assembly by introducing a rigid component in the can;
and pressing two cans together with an intervening rigid component
imposing the desired diamond surface features.
Inventors: |
JENSEN, KENNETH M.;
(SPRINGVILLE, UT) ; MIESS, DAVID; (HIGHLAND,
UT) ; POPE, BILL J.; (OREM, UT) |
Correspondence
Address: |
LLOYD W SADLER
MCCARTHY & SADLER
39 EXCHANGE PLACE
SUITE 100
SALT LAKE CITY
UT
84111
|
Family ID: |
22960876 |
Appl. No.: |
09/253581 |
Filed: |
February 19, 1999 |
Current U.S.
Class: |
51/293 ; 407/114;
407/115; 407/116; 407/6; 51/297; 51/307; 51/309 |
Current CPC
Class: |
E21B 10/5676 20130101;
B22F 2005/001 20130101; B23B 2200/081 20130101; Y10T 407/24
20150115; B23P 15/28 20130101; B22F 7/06 20130101; Y10T 407/118
20150115; B22F 2998/00 20130101; B23B 27/143 20130101; Y10T 407/245
20150115; B22F 2005/005 20130101; E21B 10/5673 20130101; Y10T
407/235 20150115; B22F 2998/10 20130101; E21B 10/5671 20200501;
B22F 2998/00 20130101; B22F 5/00 20130101; B22F 2998/10 20130101;
B22F 3/1208 20130101; B22F 7/06 20130101 |
Class at
Publication: |
51/293 ; 51/297;
51/307; 51/309; 407/6; 407/114; 407/115; 407/116 |
International
Class: |
B24D 003/00; B24D
011/00; B24D 017/00 |
Claims
We claim:
1. A method for making a superabrasive cutting tool having a chip
breaker geometry, comprising: (A) loading a can assembly with a
polycrystalline region and a carbide substrate; (B) pressing said
can assembly to impose a chip breaker feature on said
polycrystalline region; (C) sintering said polycrystalline region
to said carbide substrate to create a superabrasive polycrystalline
cutting tool; (D) removing said can assembly from said
superabrasive polycrystalline cutting tool; and (E) finishing said
superabrasive polycrystalline cutting tool.
2. A method for making a superabrasive cutting tool having a chip
breaker geometry, as recited in claim 1, wherein said loading can
assembly further comprises: (1) loading a polycrystalline region in
a first can; (2) loading a carbide substrate onto said
polycrystalline region; (3) placing a second can over said carbide
substrate opposite said first can; and (4) placing a third can over
said first can and opposite said second can.
3. A method for making a superabrasive cutting tool having a chip
breaker geometry, as recited in claim 2, wherein said pressing step
further comprises mechanically pressing said third can, said first
can and said polycrystalline region with a chip breaker feature,
prior to sintering.
4. A method for making a superabrasive cutting tool having a chip
breaker geometry, as recited in claim 2, wherein said pressing step
further comprises mechanically pressing said third can, said first
can and said polycrystalline region with a chip breaker feature
during sintering.
5. A method for making a superabrasive cutting tool having a chip
breaker geometry, as recited in claim 2, wherein said loading can
step further comprises loading a rigid component into said first
can prior to loading said polycrystalline region into said first
can, wherein said rigid component has a surface for imposing a chip
breaker geometry.
6. A method for making a superabrasive cutting tool having a chip
breaker geometry, as recited in claim 5, wherein said pressing step
further comprises pressing said outer cover thereby imposing a chip
breaker geometry from said surface of said rigid component on said
polycrystalline region.
7. A method for making a superabrasive cutting tool having a chip
breaker geometry, as recited in claim 2, wherein said pressing step
further comprises: (1) inserting a rigid component between a first
can assembly and a second can assembly, wherein said rigid
component has a first surface for imposing a first chip breaker
geometry on said first can assembly and said second surface for
imposing a second surface on said second can assembly; and (2)
pressing said first can assembly toward said second can assembly
thereby imposing said first surface and said second surface on said
first and second can assemblies.
8. A method for making a superabrasive cutting tool having a chip
breaker geometry, as recited in claim 1, wherein said finishing
said superabrasive polycrystalline cutting tool further comprises:
(1) finishing an outer diameter of said superabrasive
polycrystalline cutting tool; and (2) finishing a back surface of
said superabrasive polycrystalline cutting tool.
9. A superabrasive cutting tool, comprising: (A) a carbide
substrate; (B) a polycrystalline mass sintered to said carbide
substrate, wherein said polycrystalline mass has a top cutting
surface; and (C) one or more chip breaker features imposed in said
top cutting surface of said polycrystalline mass and wherein said
one or more chip breaker features and said polycrystalline mass has
a uniform distribution of cobalt throughout said chip breaker
features and throughout said polycrystalline mass.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] This invention relates to devices for machining of
materials. More specifically, this invention relates to
polycrystalline diamond (PCD) and polycrystalline cubic boron
nitride (PCBN) cutting tools, which for the purposes of this patent
disclosure will both be commonly referred to as "Superabrasives",
and which are intended to be installed as the cutting element in
drilling, milling, or turning operations on lathes, mills, or other
metalworking, woodworking, machining, or shaping industrial
equipment. Still more specifically, this invention relates to
polycrystalline diamond or polycrystalline cubic boron nitride
cutting tools, which have an integral chip-breaking feature.
[0003] 2. Description of Related Art
[0004] Polycrystalline diamond and cubic boron nitride CBN cutting
tools are used in industrial machinery, such as lathes, milling
machines and other drilling and reaming applications, as well as
general shaping of metals, wood, plastics, composites or other
machinable materials. A number of different configurations,
materials and geometries are used in polycrystalline diamond and
PCBN cutting tool manufacture. Typically, diamond and CBN cutting
tools that have chip-breaking features have the chip breaker
feature added after the sintering processing step. Often the chip
breaker is included in the cutting tool by use of an electric
discharge grinding or machining which is a high temperature, cobalt
depletive process. Laser etching processes or grinding steps of the
final geometry may also be used. Such process steps can induce
structural problems in the tool due to excessive heat and cobalt
binder depletion as well as increasing the manufacturing time and
cost because of the extra processing steps. These problems have
restricted the production of PCD or PCBN chip-breaker tools by
these known methods.
[0005] By way of introduction, a polycrystalline diamond cutter
(PCD) or PCBN, or superabrasive polycrystalline cutting tool, is
typically fabricated by placing a cemented tungsten carbide
substrate into a refractory metal container (can) with a layer of
diamond or cubic boron nitride crystal powder placed into the can
adjacent to one face of the substrate. Additional cans are used to
completely enclose the diamond powder and the carbide substrate. A
number of such can assemblies are loaded into a high-pressure cell
made from a low thermal conductivity extrudable material such as
pyrophyllite or talc. The loaded high-pressure cell is then placed
in a high-pressure press. The entire assembly is compressed under
high pressure and temperature conditions. This causes the metal
binder from the cemented carbide substrate to sweep from the
substrate face through the diamond or CBN grains and to act as a
reactive phase to promote the sintering of the diamond or CBN
grains. The sintering of the diamond or CBN grains causes the
formation of a polycrystalline diamond or CBN structure. As a
result the diamond or CBN grains become mutually bonded to form a
diamond or CBN mass over the substrate face. The metal binder may
remain in the diamond or CBN layer within the pores of the
polycrystalline structure or, alternatively, it may be removed via
acid leaching and optionally replaced by another material forming
so-called thermally Superabrasive tools. Variations of this general
process exist and are described in the related art. This detail is
provided so the reader may become familiar with the concept of
sintering a diamond or CBN layer onto a substrate to form a
Superabrasive cutting tool. For more information concerning this
process, the reader is directed to U.S. Pat. No. 3,745,623, issued
to Wentorf Jr. et al., on Jul. 7, 1973.
[0006] For general background material, the reader is directed to
the following United States patents, each of which is hereby
incorporated by reference in its entirety for the material
contained therein.
[0007] U.S. Pat. No. 3,745,623 describes diamond tools and
superpressure processes for the preparation thereof, where the
diamond content is present either in form of a mass comprising
diamond crystals bonded to each other or of a thin skin of diamond
crystals bonded to each other.
[0008] U.S. Pat. No. 3,767,371 describes abrasive bodies comprising
combinations of cubic boron nitride crystals and sintered
carbide.
[0009] U.S. Pat. No. 4,403,015 describes a compound sintered
compact for use in a cutting tool having particularly high
properties in respect of bonded strength, hardness, wear
resistance, plastic deformability and rigidity by bonding a diamond
or cubic boron nitride containing a hard layer to a cemented
carbide substrate with interposition of an intermediate bonding
layer.
[0010] U.S. Pat. No. 4,387,287 describes a method for shaping
polycrystalline, synthetic diamond and, in particular, to the
production of profiled parts like tools.
[0011] U.S. Pat. No. 4,854,784 describes an improved metal cutting
insert, which incorporates a polycrystalline diamond or a
polycrystalline cubic boron nitride material therein as a cutting
edge material.
[0012] U.S. Pat. No. 5,011,514 describes superabrasive cutting
elements, backed compacts and methods for their manufacture,
wherein metal coated superabrasive particles are cemented under
high pressure/high temperature conditions.
[0013] U.S. Pat. No. 5,026,960 describes an oversize compact blank
having a surface and edges that establish it as oversized. A chip
breaker pattern is formed on the compact blank surface.
[0014] U.S. Pat. No. 5,193,948 describes an insert having a cutting
segment of a polycrystalline diamond or cubic boron wafered between
two layers of a hard metal carbide is bonded into a pocket in a
standard insert and machined to form a chip breaker having a
clearance surface and expose the cutting edge of polycrystalline
material integral with the cutting segment.
[0015] U.S. Pat. No. 5,405,711 describes an indexable cutting
insert having a polycrystalline cutting edge along the entire
periphery of the insert.
[0016] U.S. Pat. No. 5,447,208 describes a superhard cutting
element having a polished, low friction, substantially planar
cutting face with a surface finish roughness of 10 micro inches and
preferably 0.5 micro inches or less.
[0017] U.S. Pat. No. 5,449,048 describes a drag bit having a
plurality of blades or ribs on its end face that has one or more
pockets milled into the top surfaces of said blades using a
ball-nosed end mill to create a plurality of pockets, each having a
spherical or a semi-spherical first end and a second end having a
semicircular configuration that intersects with the leading edge
face of the rib.
[0018] U.S. Pat. No. 5,569,000 describes a cutting insert that is
formed by making a body, which includes a chip face having an outer
peripheral edge.
[0019] U.S. Pat. No. 5,653,300 describes a superhard cutting
element having a polished, low friction substantially planar
cutting face with a surface finish roughness of 10 micro inches or
less and preferably 0.5 micro inches or less.
[0020] U.S. Pat. No. 5,704,735 describes a fly cutter wheel which
has at least one projecting tooth at a distance from its rotation
axis and a chip breaker forward of said tooth in its rotation
direction.
[0021] U.S. Pat. No. 5,709,907 describes a method of producing a
cutting tool, comprising a substrate which has a roughened surface
that presents a surface roughness of between 10 micro inches and
125 micro inches.
[0022] U.S. Pat. No. 5,722,803 describes a coated cutting tool and
a method of producing the same.
[0023] U.S. Pat. No. 5,771,972 describes a mill assembly and
whipstock assembly.
SUMMARY OF THE INVENTION
[0024] In cutting tools, which are used to machine metals,
composites, wood or other machinable materials, it is often
desirable to provide a tool having a chip breaker feature. More
particularly, it is desirable to provide a method for forming such
a chip breaker tool feature by coining a desired geometry onto a
polycrystalline diamond or PCBN surface prior to or during high
temperature and high-pressure sintering.
[0025] Therefore, it is an object of this invention to provide a
Superabrasive cutting tool with an integral chip breaker
feature.
[0026] It is a further object of this invention to provide a method
of manufacturing a Superabrasive cutting tool with a chip breaker
feature by coining the desired chip-breaker geometry onto the
diamond or CBN surface prior to high temperature/high pressure
pressing.
[0027] It is a further object of this invention to provide a method
of manufacturing a Superabrasive cutting tool with a chip breaker
feature by forming the chip breaker geometry in-situ during high
temperature/high pressure sintering.
[0028] It is another object of this invention to provide a method
of manufacturing a Superabrasive cutting tool with a chip-breaker
feature by inclusion of a rigid or semi-rigid form against the
diamond or CBN in the high temperature/high pressure cell during
sintering.
[0029] It is a further object of this invention to provide a method
of manufacturing a Superabrasive cutting tool with a chip breaker
feature that avoids the application of heat, or the removal of
cobalt by EDM or EDG or laser processes.
[0030] It is a further object of this invention to provide a method
of manufacturing a Superabrasive cutting tool with a chip breaker
feature that avoids the grinding of the final surface geometry.
[0031] These and other objectives, features and advantages of this
invention, which will be readily apparent to those of ordinary
skill in the art upon review of the following drawings,
specification, and claims, are achieved by the invention as
described in this application.
BRIEF DESCRIPTION OF THE DRAWINGS
[0032] FIGS. 1a, 1b and 1c depict three preferred embodiments of
processing steps of this invention.
[0033] FIGS. 2a, 2b and 2c depict section views of the preferred
Superabrasive cutter with the chip-breaking tool being manufactured
by the process of FIG. 1a.
[0034] FIGS. 3a and 3b depict section views of the preferred
Superabrasive cutter with the chip-breaking tool being manufactured
by the process of FIG. 1b.
[0035] FIGS. 4a, 4b and 4c depict section views of the preferred
Superabrasive cutter with the chip-breaking tool being manufactured
by the process of FIG. 1c.
[0036] FIGS. 5a, 5b, and 5c depict alternative chip-breaker tool
surface profiles of this invention.
[0037] Reference will now be made in detail to the present
preferred embodiment of the invention, an example of which is
illustrated in the accompanying drawings.
DETAILED DESCRIPTION OF THE INVENTION
[0038] This invention is intended for use in Superabrasive cutting
tools. Typically, the diamond cutting tool is held in a lathe, mill
or other machine. When the cutting tool or workpiece is rotated,
the leading edge of Superabrasive cutting tool comes into contact
with the workpiece. Certain applications are enhanced by the use of
Superabrasive cutting tools with chip breaking features. A chip
breaker is a generally non-planar surface feature of the
Superabrasive cutting tool, which is adapted specifically to cause
fractured portions of a workpiece to be broken up into short pieces
or chips that can be easily removed. The ease of chip removal is
also important to maximize machining efficiency as well as reducing
the damage done to the cutting tool by the fractured portions of
the workpiece. By preventing the formation of long continuous
chips, chip breaker tools reduce the danger to machine operators,
and permit improved coolant flow to the cutting edge, thereby
producing longer tool life and improved workpiece finish. While
chip breakers in general and even some chip breakers formed in
association with polycrystalline diamond or PCBN structures have
previously been suggested, this invention is directed to improved
processes for the manufacture of Superabrasives with chip breaker
features.
[0039] FIGS. 1a, 1b and 1c depict the preferred process steps of
three preferred embodiments of this invention. The first preferred
process shown in FIG. 1a with the cross section view of the
processed Superabrasive shown in FIGS. 2a, 2b and 2c. This process
begins 200 with the loading 100 of a can assembly, comprising a
polycrystalline diamond layer 203 loaded on a carbide substrate
region 204, the combination of which is loaded in a can assembly
having a second can or bottom 206, a first can or inner cover 207
and a third can or top cover 205. Force is applied 201 to press 101
the desired shape into the surface of the polycrystalline diamond
layer 203. This force compresses both the top cover 205 and the
inner cover 207 as well as the diamond cutter surface 203. After
pressing 101 the desired shape into the cutter, the diamond is
sintered and becomes attached to the carbide region using sintering
techniques will known in the art. The can 205, 206, 207 is then
removed 103 and the outer diameter is finished 104. After which the
back surface is finished 105. Thereby providing 202 the desired
chip breaker Superabrasive, which in this case has an edge feature
210, 213 around the periphery of the Superabrasive and a cavity
211, 212 surrounding a central region 214. This surface geometry is
shown only as an example. One of the key aspects of this invention
is its ability to produce Superabrasives with a wide variety of
alternative chip breaker geometries. Optionally, some Superabrasive
blanks may be cut 116 into smaller final cutting tools using EDM or
similar processes and finish ground as smaller tools.
[0040] FIG. 1b shows an alternative process for creating a
Superabrasive with a chip breaker feature that makes use of a rigid
or semi-rigid component inside the can to shape the diamond
surface. This rigid or semi-rigid component can consist of a wide
variety of materials, including but not limited to hexagonal boron
nitride (hbn), niobium, metals, packed crystalline material, matrix
composites, ceramics, tape case and the like. Also, this rigid or
semi-rigid component can coated or have chemical variations to
enhance sintering, facilitate its removal, or to improve the
physical properties of the final product. Moreover, the surface
texture of the rigid or semi-rigid component can be modified to be
smooth, rough, dimpled, grooved, channeled, ridged or the like.
FIGS. 3a and 3b show section views of Superabrasives being
manufactured in this alternative process. A can assembly is loaded
106 having a second can or bottom 301, a first can or inner cover
302 and a third can or top cover 303, within which is held a
diamond region 304 positioned atop a carbide substrate 305. A rigid
component 306 is positioned on top of the surface of the diamond
region 304. As the can is pressed the rigid component 306 imposes a
surface geometry on the surface of the surface of the diamond
region 304. Next, the diamond region 306 is sintered 107 and
attaches to the carbide substrate 305 using sintering processes
well known in the art. The can is removed 108 along with the rigid
component 306. The outer diameter of the Superabrasive is finished
109, along with the back surface 110. Thereby, producing a
Superabrasive having a carbide substrate 305 sintered to a
polycrystalline diamond region 304, which has a desired chip
breaker surface 307. Again, optionally, the tool can be EDM'ed 117
to smaller final tools as desired.
[0041] FIG. 1c shows a second alternative process for forming
Superabrasives having an integral chip breaker feature. This
alternative process provides for the simultaneous manufacture of
two Superabrasives in the same press step by using a rigid
component adapted for forming the chip breaker features on two
Superabrasive simultaneously by being positioned between the cans
of the two Superabrasives during the press step. Once again, this
rigid or semi-rigid component can consist of a wide variety of
materials, including but not limited to hexagonal boron nitride
(hbn), niobium, metals, packed crystalline material, matrix
composites, ceramics, tape case and the like. Also, this rigid or
semi-rigid component can coated or have chemical variations to
enhance sintering, facilitate its removal, or to improve the
physical properties of the final product. Moreover, the surface
texture of the rigid or semi-rigid component can be modified to be
smooth, rough, dimpled, grooved, channeled, ridged or the like.
FIGS. 4a, 4b and 4c show section views of a pair of Superabrasives
being manufactured by the process steps of this alternative
embodiment of the process steps of this invention. First, both cans
are loaded 111. Each can comprises a second can or bottom 402, 407;
a first can or inner cover 403, 409 and a third can or outer cover
404, 408. Each can holds a diamond region 406, 411 and a carbide
substrate 406, 411. A rigid component 412 is inserted between the
outer covers 404, 408 of the two cans. A mechanical press then
compresses the two cans to the rigid component 412, deforming the
outer covers 404, 408, inner covers 403, 409 and surfaces of the
diamond regions 406, 411. Next, the diamond regions 406, 411 are
sintered separately and attached 112 to their respective carbide
substrates 405, 410 using well-known sintering methods. The cans
are next removed 113. The outer diameters of each Superabrasive are
finished 114 and the back surface of each Superabrasive is finished
115. In this manner two Superabrasives having chip breaker features
412, 413 can be manufactured using a single high temperature
high-pressure cycle. As a final and optional step, the
Superabrasive may be cut 118 into smaller blanks for individual use
as chip breaking elements.
[0042] FIGS. 5a, 5b and 5c show three alternative chip breaker
features 504, 508, 512 imposed on the surface of the diamond or CBN
regions 503, 507, 511. As described previously, these embodiments
also have the diamond regions 503, 507, 511 sintered to a carbide
substrate 501, 506, 510. These embodiments 501, 505, 509 are
provided to demonstrate a few of the countless specific chip
breaker tool features that can be covered by the process of this
invention. The method of this invention, by pressing the desired
shape into the diamond, or alternatively cubic boron nitride (CBN),
surface produces chip breaker tools with an unmachined, virgin
diamond or CBN surface not having been EDM'ed, EDG'ed, ground,
laser eroded, or other wise heat damaged and/or depleted of cobalt.
Maintaining a uniform, or near uniform distribution of cobalt
through the diamond layer and maintaining an uncut diamond surface
provides chip breaker tools with improved durability and
temperature tolerance.
[0043] The described embodiments are to be considered in all
respects only as illustrative of the current best mode of the
invention known to the inventor at the time of filing the patent
application, and not as restrictive. For example, the processes of
1a and 1b may be performed with multiple parts in a single high
pressure/high temperature cycle, or the process of 1c may be
performed in a single high pressure/high temperature cycle.
Although the several embodiments shown here include a specific chip
breaker surface geometry, this invention is not intended to be
limited thereto. Rather this geometry is provided to show one
example, this invention is specifically adapted to address the need
for variety in Superabrasive cutting tool chip breaker geometries.
The scope of this invention is, therefore, indicated by the
appended claims rather than by the foregoing description. All
devices and processes that come within the meaning and range of
equivalency of the claims are to be embraced as within the scope of
this patent.
* * * * *