U.S. patent application number 14/192830 was filed with the patent office on 2014-08-28 for cvi bonded and coated pcbn to wc tool body.
This patent application is currently assigned to DIAMOND INNOVATIONS, INC.. The applicant listed for this patent is DIAMOND INNOVATIONS, INC.. Invention is credited to William RUSSELL.
Application Number | 20140237904 14/192830 |
Document ID | / |
Family ID | 50977040 |
Filed Date | 2014-08-28 |
United States Patent
Application |
20140237904 |
Kind Code |
A1 |
RUSSELL; William |
August 28, 2014 |
CVI BONDED AND COATED PCBN TO WC TOOL BODY
Abstract
A cutting tool and a method of making a cutting tool are
provided. The cutting tool may comprise a sintered superabrasive
tip, a tool body and a non-brazing material. The sintered
superabrasive tip may have a plurality of superhard particles. The
tool body may retain the superabrasive tip. The non-brazing
material fills a gap between the superabrasive tip and the tool
body. The method of making a cutting tool may comprise steps of
providing a superabrasive tip; providing a tool body; filling a gap
between the superabrasive tip and the tool body with a non-brazing
material; and depositing a first coating to the non-brazing
material.
Inventors: |
RUSSELL; William;
(Bloomfield, MI) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
DIAMOND INNOVATIONS, INC. |
Worthington |
OH |
US |
|
|
Assignee: |
DIAMOND INNOVATIONS, INC.
Worthington
OH
|
Family ID: |
50977040 |
Appl. No.: |
14/192830 |
Filed: |
February 27, 2014 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
61770419 |
Feb 28, 2013 |
|
|
|
Current U.S.
Class: |
51/295 ; 51/307;
51/309 |
Current CPC
Class: |
B22F 2005/001 20130101;
C04B 37/025 20130101; C04B 2237/08 20130101; C04B 2237/062
20130101; C04B 2237/343 20130101; B24D 18/00 20130101; C04B
2237/086 20130101; C04B 2237/72 20130101; C23C 16/045 20130101;
B23B 27/141 20130101; C04B 2237/363 20130101; B23B 2226/125
20130101; C04B 2237/361 20130101; C22C 26/00 20130101; C04B
2237/401 20130101; B22F 7/062 20130101; B23B 2226/315 20130101;
B24D 3/14 20130101; B23B 2228/04 20130101; C04B 2237/84
20130101 |
Class at
Publication: |
51/295 ; 51/307;
51/309 |
International
Class: |
B24D 3/14 20060101
B24D003/14; B24D 18/00 20060101 B24D018/00 |
Claims
1. A cutting tool, comprising: a sintered superabrasive tip having
a plurality of superhard particles; a tool body retaining the
superabrasive tip; and a non-brazing material filling a gap between
the superabrasive tip and the tool body.
2. The cutting tool of the claim 1, wherein the superhard particles
are selected from a group of cubic boron nitride, diamond, diamond
composite, and ceramic materials.
3. The cutting tool of the claim 1, wherein the non-brazing
material is at least one of zeolite, cubic boron nitride, diamond,
and ceramic.
4. The cutting tool of the claim 1, further comprises coatings on
the non-brazing material.
5. The cutting tool of the claim 1, wherein the non-brazing
material has melting point at least 1000.degree. C.
6. The cutting tool of the claim 4, wherein the coatings comprise
at least one of Group IVB compounds containing C, N, O, B.
7. The cutting tool of the claim 1, wherein the tool body is made
at least one of tungsten carbide, ceramic, or cermet.
8. The cutting tool of the claim 4, wherein the coatings cover the
sintered superabrasive tip and the tool body.
9. A method, comprising: providing a superabrasive tip; providing a
tool body; filling a gap between the superabrasive tip and the tool
body with a non-brazing material; and depositing a first coating to
the non-brazing material.
10. The method of the claim 9, further comprising depositing the
first coating is an infiltrant coating to bond the superabrasive
tip, the tool body, and non-brazing materials together.
11. The method of the claim 10, wherein the first coatings comprise
at least one of Group IVB compounds containing C, N, O, B.
12. The method of the claim 9, further comprising depositing a
second coating or sequence of multilayered coatings to the sintered
superabrasive tip, the tool body, and the non-brazing material.
13. The method of the claim 12, wherein the second coating or
sequence of multilayered coatings comprises at least one layer of
high temperature resistant oxide coating.
14. The method of the claim 12, wherein the high temperature
resistant oxide coating is aluminum oxide coating.
15. The method of the claim 11, further comprising bonding the
non-brazing material, sintered superabrasive tip and the tool
body.
16. The method of the claim 9, wherein the deposition of the first
coating is via chemical vapor deposition.
17. The method of the claim 9, wherein the deposition of the first
coating is via chemical vapor infiltration.
18. A cutting tool, comprising: a sintered superabrasive tip having
a plurality of superhard particles; a tool body retaining the
superabrasive tip; infiltrant bond coating between the
superabrasive tip and tool body; and high temperature resistant
coatings deposited to the sintered superabrasive tip and the tool
body.
19. The cutting tool of the claim 18, further comprising a
non-brazing material disposed between the superabrasive tip and the
tool body.
20. The cutting tool of the claim 18, wherein high temperature
resistant coating is aluminum oxide.
21. The cutting tool of the claim 19, wherein the non-brazing
material is bonded to the superabrasive tip and the tool body.
22. The cutting tool of the claim 18, wherein the superabrasive tip
has superhard particles wherein the superabrasive particles are
selected from a group of cubic boron nitride, diamond, diamond
composite, and ceramic materials.
23. The cutting tool of the claim 19, wherein the non-brazing
material comprises at least one of zeolite, cubic boron nitride,
diamond, and ceramic material.
24. The cutting tool of the claim 23, wherein the non-brazing
material is bonded by a high temperature coating or coatings.
25. The cutting tool of the claim 18, wherein the high temperature
coating is selected from at least one of Group IVB compounds
containing C, N, O, B.
26. The cutting tool of the claim 18, wherein the sintered
superabrasive tip has a backing support.
27. The cutting tool of the claim 26, wherein the backing support
is hard metal support.
28. The cutting tool of the claim 27, wherein the hard metal
support is tungsten carbide.
Description
RELATED APPLICATIONS AND CLAIM OF PRIORITY
[0001] This application claims priority to U.S. provisional Patent
Application No. 61/770,419, filed Feb. 28, 2013, titled "CVI BONDED
AND COATED PCBN TO WC TOOL BODY".
TECHNICAL FIELD AND INDUSTRIAL APPLICABILITY
[0002] The present invention relates to a cutting tool for metal
machining, comprising at least one body containing polycrystalline
cubic boron nitride (PCBN), with or without cemented carbide
backing, and on the surface of said body a hard and wear resistant
refractory coating, more specifically, to a method of using
chemical vapor infiltration (CVI) or chemical vapor deposition
(CVD) with porous or fine granule media to fill gaps between a PCBN
tool tip and a WC tool body.
[0003] Polycrystalline cubic boron nitride (PCBN), polycrystalline
diamond and polycrystalline diamond composite materials are
commonly used to provide a superhard cutting edge for cutting tools
such as those used in metal machining.
[0004] Cutting tools having cutting edges formed of a superhard
abrasive such as a cubic boron nitride (CBN) based material are
manufactured by powder metallurgical techniques and are mainly used
for the machining of cast iron and hardened steel. Several types of
CBN cutting tools are known, the majority consisting of a PCBN tip
that has been brazed onto a cemented carbide insert. Others have
the PCBN sintered directly to a cemented carbide backing of
sufficient thickness to produce an insert while yet others consist
of a PCBN-containing body without any cemented carbide backing.
[0005] Subjecting a sintered PCBN body to temperatures over
1000.degree. C. may result in unwanted structural changes in the
material. Furthermore, in the case of a brazed insert, the braze
joint will be destroyed.
[0006] Therefore, it can be seen that there is a need for a cutting
tool having a high temperature bond between the PcBN tool tip and
the tool body (WC/Co).
SUMMARY
[0007] In one embodiment, a cutting tool may comprise a sintered
superabrasive tip having a plurality of superhard particles; a tool
body retaining the superabrasive tip; and a non-brazing material
filling gaps between the superabrasive tip and the tool body.
[0008] In another embodiment, a method may comprise steps of
providing a sintered superabrasive tip; providing a tool body;
filling a gap between the superabrasive tip and the tool body with
a non-brazing material; and depositing a first coating to the
non-brazing material, wherein the first coating is an infiltrant
coating to bond the tip, body and non-brazing materials to each
other.
[0009] In yet another embodiment, a cutting tool may comprise a
sintered superabrasive tip having a plurality of superhard
particles; a tool body retaining the superabrasive tip; infiltrant
bond coating between the superabrasive tip and the tool body; and
high temperature coatings attached to the sintered superabrasive
tip and the tool body.
BRIEF DESCRIPTION OF THE DRAWINGS
[0010] The foregoing summary, as well as the following detailed
description of the embodiments, will be better understood when read
in conjunction with the appended drawings. It should be understood
that the embodiments depicted are not limited to the precise
arrangements and instrumentalities shown.
[0011] FIG. 1 is a perspective view of a superabrasive tip affixed
to a tool body according to an exemplary embodiment;
[0012] FIG. 2 is an optical image of a cross-sectional view of a
superabrasive tip affixed to a tool body according to another
exemplary embodiment;
[0013] FIG. 3 is a partially enlarged optical image of the
cross-sectional view of a superabrasive tip affixed to a tool body
as shown in FIG. 2; and
[0014] FIG. 4 is a flowchart illustrating a method of making a
superabrasive tip affixed to the tool body according to an
exemplary embodiment.
DETAILED DESCRIPTION
[0015] As used herein, the term "cutting tip" refers to a body for
grinding or cutting a work piece, which is manufactured by
fabrication processes including the step of mixing the super
abrasive particles with bond.
[0016] As used herein, the term "tool body" refers to a rigid body
that holds a cutting tip or tips firmly in place so that they can
be utilized in a turning, milling, boring, cutting, or drilling
application.
[0017] In an exemplary embodiment, a cutting tip may be made of
superabrasive particles affixed to a suitable tool body, such as,
cemented carbide hard metal. The exemplary embodiments use chemical
vapor infiltration (CVI) or chemical vapor deposition (CVD) with
porous or fine granule media to fill gaps between the superabrasive
tool tip and a tool body. The deposition by CVI or CVD may bond the
porous or fine granule media to each other and to the cutting tip
and the tool body. A high temperature resistant coating or sequence
of multilayered coatings, such as Al.sub.2O.sub.3 may be
subsequently coated as a part of the same process to provide an
enhanced wear resistance.
[0018] More specifically, the porous or fine granule media used may
survive the CVI or CVD process. Alternatively, fine granule, such
as diamond or cubic boron nitride, may be consumed by the process.
A high temperature resistant coating or sequence of multilayered
coatings may be deposited for providing additional wear resistance
to the cutting tool during machining, which may not have effects on
the strength of the bonding already established (unlike a metallic
braze).
[0019] As shown in FIG. 1, a cutting tool 10 may include a sintered
superabrasive tip 12 and a tool body 14 that contains an aperture
19. The tool body 14 may be made from a number of materials,
including cobalt cemented tungsten carbide. The tool body 14 may be
designed to retain the superabrasive tip 12. The sintered
superabrasive tip 12 may have a plurality of superhard particles,
which may be selected from a group of cubic boron nitride, diamond,
diamond composite, and ceramic materials. Between the superabrasive
tip and the tool body may exist a seam or a gap, such as a bottom
gap 15 and a sidewall gap 16, for example. The superabrasive tip 12
may or may not have a backing support. The backing support may be a
hard metal support, such as a tungsten carbide support.
[0020] As shown in FIG. 2, the cutting tool 10 may comprise a
superabrasive tip 12 having a tungsten carbide support 20. The
superabrasive tip 12 may have polycrystalline cubic boron nitride
(PcBN) particles. The cutting tool 10 may further include a tool
body 14 retaining the superabrasive tip 12. A non-brazing material
24, which may have melting point at least 1000.degree. C., may be
deposited to fill the sidewall gap 16 and the bottom gap 15. The
non-brazing material 24 may be at least one of zeolite, ceramic,
cubic boron nitride, and diamond, for example. The cutting tool 10
may further comprise coatings, such as infiltrant bond coating 22
on the non-brazing material 24 between the superabrasive tip and
the tool body. The infiltrant bond coatings 22 may cover the
sintered superabrasive tip 12, the backing support 20, and tool
body 14. The infiltrant bond coatings may comprise at least one of
Group IVB compounds containing C, N, O, B, such as TiN, TiC, and
TiCN, ZrN, ZrC, ZrCN, HfN, HfC, HfCN, for example.
[0021] A close-up optical image shown in FIG. 3, illustrates that
the coatings 22, such as TiN, may cover all cubic boron nitride
crystals 24. The coatings 22 may further provide bonding between
the non-brazing material, such as cBN, diamond, or zeolite,
superabrasive tip 20, and the tool body 14.
[0022] Since the non-brazing material has melting point at least
1000.degree. C., a high temperature resistant coating, such as
Al.sub.2O.sub.3 (not shown) may be deposited or coated to the
sintered superabrasive tip 12, the tool body 14, and non-brazing
material disposed between the superabrasive tip 12 and the tool
body 24.
[0023] FIG. 4 shows an exemplary method 400 of a process of
fabricating a cutting tool. The process includes steps of providing
a superabrasive tip in a step 401; providing a tool body in a step
402; filling a gap between the superabrasive tip and the tool body
with a non-brazing material in a step 403; and depositing a first
coating to the non-brazing material in a step 404.
[0024] The sintered superabrasive tip may be attached by some
method to the tool body. The cutting tool may then be placed in a
CVD (chemical vapor deposition) reaction vessel, whereupon air is
removed and replaced by gases comprising both inert and reactive
species. Metallic deposition may employ gases comprising metal
carbonyl or metal-acetal-acetonates, for example, iron
pentacarbonyl. Ceramic deposition precursors may refer to N, C, and
O containing compounds that crack under temperature less than
1000.degree. C. In some exemplary embodiments, the ceramic
deposition precursors may include TiCl.sub.4, NH.sub.3, CH.sub.4,
AlCl.sub.3, (Me).sub.3Al, N.sub.2, CH.sub.3CN, H.sub.2, CO,
CO.sub.2 or mixtures thereof, for example. The gases penetrate via
diffusion into gaps, seams, contact voids, and deposit on heated
solid surfaces, external or internally gas-accessible, in the
equipment. Upon condensation on the surface, the condensed phases
chemically react to form a new solid phase as a first coating. The
first coating may be an infiltrant coating to bond the
superabrasive tip, the tool body, and non-brazing materials
together. For example, TiCl.sub.4+CH.sub.4.fwdarw.TiC solid+gas
phase 4HCl. This solid phase adhesively bonds to the solid surfaces
depending on chemical affinity. The quality of the solid phase
(crystal perfection, density) depends on temperature and affinity
to the solid surface(s) upon which they condense. The process of
infiltration, condensation and reaction to form a new solid phase
continues as long as temperature is high enough and reactants are
present. Once the pores are filled, then straight-forward coating
on surfaces of the superabrasive tip and the tool holding material
may occur.
[0025] Gas accessibility is determined by the gas diffusion, which
depends on temperature and pressure. Lower pressure allows deeper
diffusion of reactive gases into seams and gaps in the tool
assembly. Gas deposition, reaction and solidification rates forming
a solid must be controlled to prevent premature "plugging" of
narrow gaps and seams, thus reducing the film contact area and
joint strength. This typically requires that the temperature be
lowered, or gas phase partial pressure of reactants be adjusted.
Finally, the quality of the film formed, its crystallinity and
crystal orientation, depends on temperature and time. If the film
is formed and quenched too quickly, it may be of poor quality and
crack either within the film or at the film-tip or film-tool
interface.
[0026] It is important that the gas-phase precursors react with
solid surfaces indiscriminately, regardless of orientation in the
reactor. So-called "line-of-sight" deposition processes, e.g.,
physical vapor deposition (PVD), may not be as effective as the
gas-phase precursors, and may not penetrate gaps and seams, thus
reducing the area of adhesion and adhesion strength
considerably.
[0027] Furthermore, non line-of-sight CVD coating does not require
tools to be flipped over and processed multiple times to form a
uniform coating. CVD coats all gas-accessible surfaces in one
furnace cycle.
[0028] Gas phase reactions that may also be considered CVD include
any gas-solid reactions such as oxidation, hydration, or
carburization. The solid constituents may adsorb onto surfaces
first, then react and crystallize, or may form above the surface
and deposit by solid-surface tension forces prior to reaction and
crystallization.
[0029] Post-CVD treatment, e.g., annealing may be conducted to
improve the quality of the film or film-tip/film-tool adhesion.
[0030] One or more steps may be inserted in between or substituted
for each of the foregoing steps 401-404 without departing from the
scope of this disclosure.
[0031] While reference has been made to specific embodiments, it is
apparent that other embodiments and variations can be devised by
others skilled in the art without departing from their spirit and
scope. The appended claims are intended to be construed to include
all such embodiments and equivalent variations.
* * * * *