Wear resistance of diode laser-clad Ni/WC composite coatings at different temperatures

Ni/WC composite coatings with different weight percentage (0-60%) of WC particle were produced on a stainless steel by diode laser-cladding technology with the aim to improve wear resistance of the stainless steel in the present study. The effects of laser power, WC particle content and rare earth element (La) on the quality of the coatings were investigated. The influences of WC content on microstructure and hardness were investigated. The friction and wear behavior of the laser-clad coatings at room temperature and elevated temperatures of 600 °C and 700 °C were evaluated using a ring-on-block tribometer. Results revealed that the laser-clad composite coatings with WC content ranging from 20 wt.% to 60 wt.% were free of cracks and pores by controlling laser power level and adding 0.4 wt.% La. An increase in WC content increases wear resistance significantly at three test temperatures except for the Ni-20% WC coating. The phase structure of the oxidation films formed during the wear test process played important role on the wear behavior of the laser-clad coatings.