Wear resistance and thermal conductivity of diamond/Cu-1Cr mechanical milled coatings after high temperature annealing

In this work, diamond/Cu-1Cr composite coatings were successfully prepared on T2 Cu substrate via mechanical milling method. The effects of high temperature annealing on the microstructure, wear resistance and thermal conductivity of coatings have been studied. The results showed that the diffusion ability of copper and chromium was enhanced to form segregation after annealing at 700 °C, while chromium carbides were formed on the surface of diamond. When the annealing temperature was higher than 800 °C, the loose lamellar structure was formed from the surface to the inside of the coating. The friction coefficient of the annealed coating at light load was lower than that of the unannealed coating, much lower than that of pure copper. The wear resistance of the unannealed coating was far superior to that of pure copper, but it decreased slightly after annealing. After annealing at 700 °C, the thermal conductivity of the coated sample was significantly improved to 346.91 W·m−1·K−1. Increasing the annealing temperature would result in the deterioration of heat conduction. [Display omitted] •High temperature annealing was used to improve the performance of diamond/Cu-1Cr mechanical milling coatings.•The diamond particle size in the coating was mainly distributed between hundreds of nanometers and several micrometers.•The wear volume of the coating was calculated by the established model, and the wear resistance was investigated.•The thermal conductivity of the coating was investigated.