| 摘要 |
<p>Composite diamond grains which comprise heat-resistant core particles having distributed thereon independent diamond crystal particles or having totally covered on the surface thereof diamond crystal membrane are disclosed. A process for producing the composite diamond grains by vapor phase process is also disclosed. In a filament process which is one of the vapor phase processes, tantalum is suitable as filament. Since tantalum is liable to cause hydrogen embrittlement, a treatment for tantalum improved in this point is also disclosed.</p> |
