Design of Process for the Preparation of Ni-Al Intermetallic Compound Protective Layer

Laser cladding technique was used to produce a layer of Ni60 alloy on the surface of 316L stainless steel. After choosing the best laser cladding parameters to create the Ni60 alloy coating, pure Al coating was sprayed onto the coating's surface using thermal spraying technology. To create a protective layer of Ni-Al intermetallic compounds, two coated samples were manufactured and heated to 620 °C in a heat treatment furnace for varying amounts of time. Macro morphology, microstructure, element distribution, and properties of the Ni-Al intermetallic compound layer samples were analyzed. The findings indicate that the optimum overall effect of the cladding coating was achieved using laser cladding parameters of 1.5 kW laser power, 350 mm/min scanning speed, and 9.4 g/min powder feeding speed. The thickness and homogeneity of the Ni-Al intermetallic compound were relatively good during a diffusion time of five hours. Tests of high-temperature oxidation under these circumstances revealed that the intermetallic compound might be converted into a double-layer metal oxide coating, enhancing the resistance to oxidation.