Abstract: The WC coatings were prepared by the detonation gun spray technique. Their tribological properties at high temperature were investigated on a HT-1000 high temperature friction/wear tester. The worn surface and element distribution were analyzed by scanning electronic microscope(SEM). The phase structure was analyzed by Xray diffraction. The results show that the WC coatings， heaped by the snowflakelike particles， are of the mountain ground shape. The bonding interface is very tight. Under definite temperature， the friction coefficient gradually minishes with the temperature increase， and the minimum is achieved at 550℃. The wear mass loss increases as the temperature increases， with minus addition appearing at 550℃ because of the material transfer. The worn surface shows laceration， slight adhesive wear and abrasive wear below 350℃. However， the wear mechanism is the combination of desquamation， severe adhesive wear and oxidization wear at 550℃. With the continuous temperature increase， the friction coefficient is balanced and lessens below 300℃，which is larger and shows bigger fluctuation within the temperature range from 350℃ to 550℃. The worn surface shows desquamation， adhesive wear and oxidation wear.

Key words: WC coatings, friction coefficient, high temperature, continuous heatingup, wear mechanism