Microstructure and wear behavior of laser cladding VC-Cr_7C_3 ceramic coating on steel substrate

摘要

To enhance the wear resistance of mechanical components, laser cladding has been applied to deposit in situ VC-Cr_7C_3 ceramic coating on steel substrate using a pre-placed powder consisting of vanadium, carbon and high-carbon ferrochrome. The laser cladding samples were subjected to various microstructure examinations, microhardness and wear tests. The results showed that defect-free coating with metallurgical joint to the steel substrate was obtained. The quantity of VC-Cr_7C_3 particles gradually increased from the bottom to the top of the coating. The VC particles in nanometer were observed within the coating. Average hardness of the coating up to 1050 HV was significantly higher than that of the substrate 150HV. Wear tests indicated the wear resistance of the clad coating was 4 times that of the steel substrate.