Characterization of wear properties of the functionally graded material deposited on cast iron by laser-aided additive manufacturing

In this study, functionally graded material (FGM) was deposited on cast iron substrate by laser-aided additive manufacturing (LAAM). Inconel 625 nickel-base superalloy was firstly deposited on the substrate as a buffer layer, on which the stainless steel 420 (SS420) layers were subsequently prepared. The cracking issue was successfully eliminated in the deposited materials. With the optimized process parameters, the FGM with thickness up to 4.0 mm was achieved without cracks and other obvious defects. The SS420 layers showed fine dendritic microstructure derived from the rapid cooling rate of the LAAM process. Wear test results indicated that the FGM shows excellent wear resistance, especially under lubricated condition.