Wire Arc Additive Manufacturing for Stainless Steel-Nickel Superalloy Bimetallic Components

Nickel superalloys have commonly been used in the aerospace, maritime platform, and nuclear industry; because of their high mechanical performance, high thermal creep strength, high corrosion resistance and oxidation resistance, it is one of the best choices for severe environments such as high temperature, high pressure, and corrosive environment. However, due to its high fabrication cost, it is unnecessary to build all the workpieces up with nickel alloys; an appropriate method for manufacturing dual-layer structure with nickel superalloys and body materials has great potential for reducing the material cost without compromising the overall performance. In addition, the high mechanical properties give nickel alloys an edge in industrial production. However, it also limits the manufacturing process of nickel alloys as well—the high strength makes the conventional “subtraction” manufacturing process a difficult task, especially for joining dissimilar materials that require a more accurate shape of the part. Additive manufacturing (AM) processes can build a workpiece with complex geometry. With several AM processes evaluated, the Wire arc additive manufacturing (WAAM) process is considered the best choice for manufacturing these high-strength alloys joined with dissimilar materials for producing quality bimetallic parts.