Tribological Properties of Aluminum-Ceramic Composite Coating by Plasma Thermal Spary

摘要

Al-SiC Composite layer was prepared by plasma thermal spray on aluminum substrate using composite powder prepared by mechanical alloying. Mechanically alloyed powder was achieved after 24 h ball milling in evacuated container. The correlations between process conditions and thickness/porosity were analyzed, and increase of hardness was confirmed. The friction tests of the composite layers and commercial aluminum alloys for comparison were performed in the temperature range of 20～260°C with the interval of 40°C with steel counter-face. Friction coefficient was recorded during test sequence, and the microstructure of surface and debris was investigated by optical and scanning electron microscope. Friction coefficients of composite and aluminum alloys at room temperature were similar except pure aluminum. As the temperature increase, friction coefficient was increased rapidly in AC4C, AC2A. But friction coefficient of Al-SiC composite was not increased so much up to 220°C. Consequently, the reinforcement of SiC into aluminum matrix increased the stability of friction coefficient as well as wear resistance.