Effect of heat treatment on the structure and properties of Ti coating deposited on the surface of diamond grains

Ti coating was prepared on the surface of diamond grains by the method of vacuum evaporation,and then Ti-coated diamond grains were heated at different temperature respectively.The surface morphology,composition and phase of the coating were detected by SEM,EDS and XRD,and the static compressive strength of the diamonds were tested by the static compressive strength tester for single diamond grain.The results showed that the diamond grains were carbonized at the temperature of 880℃,and Ti coating could react with diamond at the interface.Punctiform TiC coating was generated at the temperature of 880℃,and with the time going on,it grew up into a snowflake shape.However,when the temperature reached 920 ℃,the Ti coating became gradually oxidized to be TiO;TiC coating can improve the thermal stability and static compressive strength of the diamond grains.Compared with uncoated diamond,the compressive strength of Ti-coated diamonds was increased by 14%.