The Ni/AlN composite coating was prepared for increasing corrosion and elements interdiffusion resistance of GH3535 alloy in molten fluoride salts,and the effect of mechanical interlocking on adhesion strength between AlN layer and nickel coating was also studied.Results indicated that the adhesion strength between AlN layer and nickel coating could be signifi-cantly enhanced through mechanical interlocking effect,which effectively prevented the nickel coating from flaking off at elevated temperature.Through an etching pre-treatment of AlN layer,the corrosion resistance of the Ni/AlN coated GH3535 alloy in molten FLiNaK salt was further improved,and elements interdiffusion between the substrate and nickel coating was completely suppressed.AlN layer as a diffusion barrier remained compact and continuous in Ni/GH3535 system after high-temperature molten salt corrosion.Moreover,a Ni-P layer consisting of Ni3P and Ni phases formed in the Ni coating after corrosion.