Exploration of the wear behavior of laser cladding martensitic steel/Ni composite coating

The 18Ni300/Ni functional grade material (FGM) coatings were designed and prepared to improve the wear resistance of stainless steel surfaces by directed energy deposition. The 18Ni300 coating was austenitised with the addition of Ni, and the phase composition was dominated by γ-Fe and FeNi3. The microstructure of 18Ni300/Ni FGM is a typical dendritic structure, in which columnar dendrites and equiaxial dendrites predominate, and Ni elements are segregated between the dendrites. Crystallographic analyses confirmed that with the increase of Ni content, the grain size decreases and the fine grain strengthening effect is obvious. The average microhardness of the 18Ni300/Ni FGM surface increased by 39.8 % compared to the substrate. Sliding wear tests have revealed that the wear resistance of 18Ni300/Ni FGM increases significantly with increasing Ni content. 18Ni300/Ni FGM coatings have significantly improved wear resistance at room temperature, with wear volume on the FGM coatings surface reduced by 54.5 % compared to the substrate surface.