Abstract
The synthesis of commercially available polycrystalline diamonds (hereafter PCD) with metallic and non-metallic sintering agents and their physical properties were briefly introduced. The PCD with non-metallic sintering agents such as alkaline earth carbonates had excellent heat-resistant properties, but because of the higher viscosity of molten carbonate, it is very difficult to infiltrate into the diamond layer with a grain size below 5 μm. In this article, recent advances in the synthesis of a fine-grained PCD under a static high pressure of 7.7 GPa were reviewed. Especially, experimental techniques such as sample assembly, pretreatment of natural diamond powder, etc, and sintering agents for the synthesis of PCD with a grain size from submicron to 100 nm were described.
