| 摘要 |
PURPOSE:To obtain the high density polycrystalline sintered body in which diamond and cubic boron nitride are tightly bonded by using hexagonal boron nitride contg. diamond as a raw material, activating it by a compound contg. nitrogen and hydrogen and executing reaction sintering. CONSTITUTION:Hexagonal boron nitride(hBN) contg. diamond, preferably 20 to 60wt.%, is subjected to vacuum heating and is deaerated, which is thereafter heated in a mixed atmosphere of N2 gas or H2 gas. Next, an H-N contg. compound decomposed to vaporize at >=100 deg.C (such as NH4NO3) is added to the above (the amt. to be added is preferably regulated to 1 to 3wt.%), and the mixture is subjected to reaction sintering under high temp.-high pressure of >=1000 deg.C and >=4G pa, by which the polycrystalline sintered body can be obtd. |
