Microstructure and Properties of Nanocrystalline Ni Coatings after Laser Cladding

Nanocrystalline nickel coatings were prepared on low-carbon steel matrix by the self-manufactured jet electroplating equipment.Then the coatings were processed by laser cladding.The effect of average pulse current density on the microstructure of nanocrystalline Ni coatings was studied,and the effect of laser cladding on the morphology,microhardness and bonding strength of nanocrystalline Ni coatings was also investigated.The results show that the surface planarization of the nanocrystalline Ni coating was improved with the increase of pulse current.The coating treated by laser cladding had high density,the microhardness increased from 597.5 HV to 658.2 HV,the bonding strength increased from 10.2 MPa to 19.5 MPa.