Claims
- 1. A preform cutting element comprising a body of a superhard polycrystalline material comprising a plurality of bonded diamond crystals integrally formed with a metallic substrate, the diamond crystals having an average particle size substantially greater than 15 microns, a plurality of interstitial regions among the diamond crystals and a catalyzing material, the body having at least an 85% by volume diamond density and a cutting surface, wherein a first interstitial region adjacent to at least a portion of the cutting surface is substantially free of the catalyzing material and a second interstitial region in a portion of the body in contact with the substrate contains the catalyzing material, wherein the first interstitial region extends beneath the cutting surface at least about 0.1 mm and the second interstitial region has an average thickness greater than 0.15 mm.
- 2. The preform cutting element of claim 1, wherein the cutting element is mounted upon a cutting face of a fixed cutter rotary drill bit.
- 3. The preform cutting element of claim 1, wherein the cutting element is mounted upon a body of a rolling cutter drill bit.
- 4. The preform cutting element of claim 1, comprising a cutting element with the cutting surface adapted for use as a cutting insert in a machining operation.
- 5. The preform cutting element of claim 1 wherein the substrate comprises tungsten carbide cemented with an iron group binder material.
- 6. The preform cutting element of claim 1 wherein the first interstitial region extends beneath the cutting surface to a depth of at least an average diameter of the diamond crystals.
- 7. The preform cutting element of claim 1 wherein the first interstitial region extends beneath the cutting surface to a depth of between about 0.2 mm and about 0.3 mm.
CROSS REFERENCE TO RELATED APPLICATIONS
This application claims priority from U.S. Provisional Patent Application No. 60/234,075 filed Sep. 20, 2000, and from U.S. Provisional Patent Application No. 60/281,054 filed Apr. 2, 2001.
US Referenced Citations (94)
Foreign Referenced Citations (16)
Number |
Date |
Country |
0300699 |
Jan 1989 |
EP |
0329954 |
Aug 1993 |
EP |
0617207 |
Sep 1994 |
EP |
0595631 |
Apr 1997 |
EP |
0787820 |
Aug 1997 |
EP |
0500253 |
Nov 1997 |
EP |
0595630 |
Jan 1998 |
EP |
0612868 |
Jul 1998 |
EP |
0860515 |
Aug 1998 |
EP |
1349385 |
Apr 1974 |
GB |
2048927 |
Dec 1980 |
GB |
2268768 |
Jan 1994 |
GB |
2323398 |
Sep 1998 |
GB |
59-219500 |
Dec 1984 |
JP |
9323204 |
Nov 1993 |
WO |
WO9634131 |
Oct 1996 |
WO |
Non-Patent Literature Citations (1)
Entry |
Translation of Japanese Unexamined Patent Application No. S58-91691, “Diamond Sintering and Processing Method,” Shuji Yatsu and Tetsuo Nakai, Inventors: Appliaiton filed May 24, 1983; Applicant: Sumitomo Electric Industries. |
Provisional Applications (2)
|
Number |
Date |
Country |
|
60/234075 |
Sep 2000 |
US |
|
60/281054 |
Apr 2001 |
US |