Characterization and Tribological Behavior of Ni-base Alloy Coatings Prepared by Electro-spark Deposition

Ni-base alloy coatings on carbon steel surface were prepared by electro-spark deposition technology and the characterization and tribological behavior of the coatings were investigated. The research results show that the microstructure of Ni-base alloy coating can be divided into three typical areas: the white alloy zone, transition zone and overheating-affected zone. The hardness across the interface of the coating and substrate, in which chemical elements transferred from the coating to substrate, gradually decreases with the depth away from the coating surface. The friction coefficient slightly decreases, while the wear loss increases with the increase of load. The main wear mechanism of the coating is micro-cutting wear at light load friction, and gradually changes into mixture of micro-cutting wear, multi-plastic deformation wear and adhesive wear at heavy load friction.