Methods of improving sintering of PCD using graphene
View Patent ↗A method of making diamond including mixing graphene with diamond seed to form a powder mixture, and then sintering the powder mixture, in the absence of a transition metal catalyst, at high pressure and high temperature; and a method of making a polycrystalline diamond compact including mixing graphene in diamond powder to form a powder mixture with less than about 50% graphene by weight, and then sintering the powder mixture, in the absence of a transition metal catalyst, at high pressure and high temperature.
1. A method of making diamond comprising:
sintering nano-scale graphene having an aspect ratio of 500 to 2000, in the absence of a transition metal catalyst, at high pressure and high temperature, wherein the sintering is performed at a pressure of up to about 75 kBar.
2. The method of claim 1 , wherein the sintering is performed for a time period of about 5 minutes.
3. The method of claim 1 wherein the sintering is performed at a pressure of about 75 kBar and a temperature of at least about 1400° C.
4. The method of claim 1 , wherein the sintering is performed at a pressure of at least about 45 kBar and a temperature of at least about 700° C.
5. The method of claim 1 , wherein the sintering is performed at a pressure of at least about 55 kBar and a temperature of at least about 1000° C.
6. A method of making diamond comprising:
mixing nano-scale graphene having an aspect ratio of 500 to 2000 with diamond seed to form a powder mixture; and
sintering the powder mixture, in absence of a transition metal catalyst, at high pressure and high temperature, wherein the sintering is performed at a pressure up to about 75 kBar.
7. The method of claim 6 , wherein the diamond seed is equal to or greater than about 0.01% by weight of the powder mixture.
8. The mixture of claim 6 , wherein the diamond seed is equal to or greater than about 0.1% by weight of the powder mixture.
9. The method of claim 6 , wherein the sintering is performed for a time period of about 5 minutes.
10. The method of claim 6 wherein the sintering is performed at a pressure of about 75 kBar and a temperature of at least about 1400° C.
11. The method of claim 6 , wherein the sintering is performed at a pressure of at least about 45 kBar and a temperature of at least about 700° C.
12. The method of claim 6 , wherein the sintering is performed at a pressure of at least about 55 kBar and a temperature of at least about 1000° C.
13. A method of making a polycrystalline diamond compact comprising:
Mixing nano-scale graphene having an aspect ratio of 500 to 2000 in diamond powder to form a powder mixture with less than about 90% graphene by volume; and
sintering the powder mixture, in the absence of a transition metal catalyst, at high pressure and high temperature, wherein the sintering is performed at a pressure up to about 75 kBar.
14. The method of claim 13 , wherein the powder mixture includes about 1% to about 10% graphene by volume.
15. The method of claim 13 , wherein the sintering is performed for a time period of at least about 5 minutes.
16. The method of claim 13 wherein the sintering is performed at a pressure of about 75 kBar and a temperature of at least about 1400° C.
17. The method of claim 13 , wherein the sintering is performed at a pressure of at least about 45 kBar and a temperature of at least about 700° C.
18. The method of claim 13 , wherein the sintering is performed at a pressure of at least about 55 kBar and a temperature of at least about 1000° C.
19. The method of claim 1 , wherein the sintering is performed for a time period of up to about 10 minutes.
20. The method of claim 1 , wherein the high pressure and the high temperature of the sintering process provide a driving force of greater than about 2 kJ/mol when the graphene is converted to diamond.
21. The method of claim 6 , wherein the sintering is performed for a time period of up to about 10 minutes.
22. The method of claim 6 , wherein the high pressure and the high temperature of the sintering process provide a driving force of greater than about 2 kJ/mol when the graphene is converted to diamond.