Tribological Properties of Ni-clad Nano-Al2O3 Composite Coatings by High-energy Laser Irradiation

Ni-clad nano-Al2O3 composite coatings were prepared on carbon steel plate by high power continuous wave CO2 laser beam. The fabrication of Ni-clad nano-Al2O3 composite coatings was investigated. The friction properties were examined under dry sliding condition using pin-on-disc tester. The results showed that the Ni-clad nano- Al2O3 composite coating had a microhardness value of 810Hv, greater than for without treated ones. The Ni-clad nano-Al2O3 composite coating possessed not only a higher wear resistance but also a lower friction coefficient. It is interest to note that the wear mass loss and friction coefficient of Ni-clad nano-Al2O3 composite coatings reduced to about 38% and 40% in comparison with those without coating respectively. The nano-Al2O3 were uniformly distributed in the carbon steel matrix and greatly increased the microhardness and tribological properties of the Ni-clad nano-Al2O3 composite coatings. The results also showed that the amount of Al2O3 significantly affected wear resistance of Ni-clad nano-Al2O3 composite coatings but they had little influence on their friction coefficient.