Polycrystalline diamond compacts having improved wear characteristics, and method of making the same
A method of making a polycrystalline diamond compact includes mixing a diamond particle feed with a binder to form a mixture, forming the mixture into a precompact, heating the pre-compact in a non-oxidizing atmosphere to substantially drive off the binder, oxidizing the pre-compact in an oxidizing atmosphere at a temperature and for a time sufficient to burn off non-diamond carbon without overoxidizing diamond, and sintering the pre-compact at high pressure and high temperature to form a polycrystalline diamond compact. The method may also include oxidizing the diamond particle feed prior to mixing with the binder.
1. A method of making a polycrystalline diamond compact, comprising:
mixing a diamond particle feed with a binder to form a mixture;
forming the mixture into a pre-compact;
heating the pre-compact in a non-oxidizing atmosphere to drive off at least a portion of the binder and to form non-diamond carbon from the binder;
oxidizing the pre-compact in an oxidizing atmosphere at a temperature and for a time sufficient to burn off non-diamond carbon formed in the pre-compact heating step without over-oxidizing diamond; and
sintering the pre-compact at high pressure and high temperature to form a polycrystalline diamond compact.
2. The method of claim 1 , wherein the non-oxidizing atmosphere comprises hydrogen.
3. The method of claim 1 , wherein the non-oxidizing atmosphere comprises argon.
4. The method of claim 1 , wherein oxidizing atmosphere is air.
5. The method of claim 1 , wherein oxidizing the pre-compact is performed at a temperature from about 500° C. to about 750° C. and for a time from about 10 minutes to about 240 minutes.
6. The method of claim 1 , further comprising placing the pre-compact in a cup of a high pressure, high temperature apparatus prior to oxidizing the pre-compact.
7. The method of claim 1 , further comprising oxidizing the diamond particle feed prior to mixing with the binder.
8. The method of claim 7 , further comprising placing the diamond particle feed in a cup of a high pressure, high temperature apparatus prior to oxidizing the diamond particle feed.
9. A polycrystalline diamond compact having improved wear characteristics made by a process according to claim 1 .
10. The method of claim 6 , further comprising placing a substrate in the pre-compact assembly to enclose the pre-compact.
11. The method of claim 1 , wherein the pre-compact retains sufficient strength and coherence after the heating step to be placed into a cup of a high pressure, high temperature apparatus.