A functional gradient TiC/Ni alloy composite coating was produced by one step
plasma cladding with multi-layer pre-placed
on carbon steel substrate.The distributions of the main elements in the plasma cladded coating were investigated by EPMA with both face-scanning and characteristic X-ray scanning. The contents of TiC were measured using an image analyzer.The results show that TiC particles exhibit a continuous increase both in size(from 1.25～2.5μm to 15～25μm)and in volume fraction(from 3% to 18%)from the bottom to the top surface, and their morphology changes correspondingly from small globe to coarse flowers-like cluster, and the structure of matrix present gradient distribution from coarse columnar crystal to cellular-dendrites to thin dendrites.Si, Fe elements decrease and Ti, Cr increase progressively, Ni is relatively uniform from bottom to top surface in the plasma cladded coating.The collision and sintering of TiC particles and force couple effects in the plasma melting bath lead to the formation of the
gradient coating.There is no any layer interfaces in the plasma cladded coating, but microinhomogenety of ceramics phase in the coating is observed.The hardness of the cladded coating has a gradient change, corresponding to the distribution of TiC particles.