Effect of substrate temperature on SiC interlayers for diamond coatings deposition on WC-Co substrates

• The temperature dependence of SiC films synthesized on WC-Co was investigated.
• Three types of morphologies of SiC films were identified at 600 °C, 850 °C and 950 °C.
• Diamond coatings produced on different interlayer exhibited the similar structure.
• Diamond coating on SiC interlayer produced at 850 °C possessed the best adhesion.

SiC films were synthesized on WC-Co substrate as interlayers for improving the adhesion of diamond coatings. The influence of the substrate temperature on the SiC films was investigated. The results showed that when the temperature was 600 °C, the film was formed of loose agglomerates piled up by SiC nanoparticles. As the temperature increased to 850 °C, shell structure composed of SiC particles and graphite replaced the agglomerates. When the temperature exceeded 950 °C, flower-like SiC clusters and graphite spherical particles coexisted in the surface, and Co2Si particles embedded at the SiC/substrate interface. SiC films deposited at 600 °C, 850 °C and 950 °C were typically used as interlayer for diamond deposition. The coatings exhibited the similar nano-diamond structure. However, the diamond coating on the interlayer produced at 850 °C possessed the best adhesion; and the diffusion of Co was effectively inhibited by SiC interlayer which would not interfere with the process of diamond deposition.