Tribological properties of Ni-Covered cast WC coating by laser cladding process

摘要

Since the beginning of 80s,the studies on the laser cladding of WC coating have been conducted widely.However,it is still less used in practice until now due to hte folloowing reasons.The coatings are easily cracked,the change of hardness between the coating and substrate is very abrupt,the WC powder cna be burned and some brittle phases can be produced,the distribution of hard phases in the coating and the friction and wear mechanism have been less studied.Directing against this situation,we prepared the crack-free Ni-covered cast tungsten carbide gradient coating by laser cladding process and studied systematically the structural characteristics and tribological properties of this coating.The results showed that the quality of coating is fine without cracks and its wear resistance is higher than that of hte substrate many times.