Sintering of Diamond Using Non-metallic Catalyst as a Sintering Agent

Abstract

Synthesis of polycrystalline diamond compact (PCD) with high heat resistant properties is a big challenge for specialized abrasive application such as in cutting tools, in rock dills etc. The present paper reviews the sintering behavior of natural diamond powder-magnesium carbonate system under the conditions of 7. 7 GPa and 1850-2450°C and its thermal resistant properties. Neither graphitization nor crackings were observed either in or on the compact after the heat treatment between 900∼1400°C for 30 min in vacuum. PCD after the treatment at 1400°C had a high hardness of 55 GPa in Knoop hardness scale. This result suggests that magnesium carbonate is a superior additive for synthesis of PCD with high heat resistant properties.