The Wear Resistance of AlTiCrN Coating on Aluminum Alloy by Vacuum Arc Ion Plating

Aluminum alloy has been widely used in automobile parts due to its light weight, corrosion resistance and other advantages, but it is soft and has poor wear resistance. So, its surface needs strengthening treatment. AlTiCrN and TiN coatings were deposited on the aluminum alloy by vacuum arc ion plating. The microstructure, mechanical properties, bonding property and wear resistance of the coatings were analyzed by scanning electron microscopy, X-ray diffraction, nano indentation, Rockwell indentation and friction and wear tests. The results show that the surface of AlTiCrN coating on the aluminum alloy substrate was flat with few "droplets". The AlTiCrN coating exhibited a TiN phase, which was preferentially oriented with the (200) crystal plane. The AlTiCrN coating had fine grains and possessed a hardness of 33.7 GPa, which was 67 times and 66.8% higher than that of aluminum alloy substrate and TiN coating, respectively. The AlTiCrN coating was firmly bonded to the aluminum alloy substrate. During the friction and wear process, the AlTiCrN coating exhibited functions of anti-sticking and reducing the friction coefficient. The wear resistance of the coated aluminum alloy was significantly enhanced.