Abstract
This paper describes some experiments with ceramic coating on diamond grains in order to get tight bonding and to make easy to use in air. Commonly used 3 types of diamond grains ; natural diamond, synthetic blocky diamond, synthetic irregular diamond are tested. And TiC ceramics is selected as coating material. Coating is carried out by CVD process using out-heating furnace. Then results obtained are as follows. (1) Bonding strength of TiC ceramics on diamond grain varies with the type of grain and it becomes greater in synthetic blocky diamond natural diamond synthetic blocky diamond order. (2) Structure of synthetic irregular diamond consists of micro-grains and these of synthetic blocky diamond and natural diamond consist of columnar structure, therefore, structure of coating film depends on the sort of diamond. (3) In the case of synthetic irregular diamond grain coated TiC film protects from oxidation mass loss up to 800°C in air.
