Thermal Damage Behaviors and Mechanism of Ni-W-B Clad Diamonds by Electroless Plating

摘要

Diamonds suffering from thermal damage at high temperature are observed through scanning electron microscope before and after diamonds surface are plated with Ni-W-B film by electroless plating. The observed results show that the diamond with a thin film of Ni-W-B alloy suffers from plane damage and the bare diamond suffers from body damage. Thermodynamic analysis and X-rays diffraction results indicate that W in the film firstly acts with oxygen and then oxide deoxidizes and combines with the surface carbon atoms to form a symmetrical carbide film coating on diamond, which is the protection mechanism of the Ni-W-B alloy acting on diamond. This process postpones the thermal damage progress to diamond and improves the property of oxidization resistance.