Patent ID: 9630853
Date: 2017-04-25
CPC Classifications: B26F,B82Y,C01B,C03B,C04B,Y10T

Claim:
1. A method for manufacturing a polycrystalline diamond, the method comprising steps of: preparing non-diamond carbon having D90 grain diameter of (average grain diameter+average grain diameter×0.9) or less; and converting and sintering the non-diamond carbon under an ultrahigh pressure and at a high temperature without addition of a sintering aid or a catalyst, wherein: sintered diamond grains constituting the polycrystalline diamond have an average grain diameter of more than 50 nm and less than 2500 nm and a purity of 99% or more, and the sintered diamond grains have a D90 grain diameter of (average grain diameter+average grain diameter×0.9) or less.