HEAT-RESISTANT COMPOSITE DIAMOND SINTERED PRODUCT AND METHOD FOR PRODUCTION THEREOF

摘要

A heat-resistant composite diamond sintered product which comprises a sintered product from a superfine synthetic diamond powder, characterized in that said sintered product is produced with no sintering auxiliary and is a composite sintered product comprising diamond crystals and a trace amount of non-diamond carbon formed and has a Visckers hardness of 85 GPa or more; and a method for producing the above heat-resistant composite diamond sintered product which comprises encapsulating a synthetic diamond powder having an average particle diameter of 200 nm or less by the use of a Ta or Mo capsule, and heating and pressuring said capsule using a super high pressure synthesis apparatus under a condition wherein diamond is thermodynamically stable, that is, of a temperature of 2100°C or higher and a pressure of 7.7 GPa or more, to thereby sinter the diamond powder.