Inconel-600 superalloys have a number of applications in space and aerospace sector due to its unique characteristics of high strength at elevated temperature, low weight, corrosion resistance and high wear resistance. However, due to these characteristics, Inconel-600 superalloy poses challenges in joining. Therefore, an attempt has been made to resolve these issues using microwave hybrid heating (MHH). The characteristics of the constituents of MHH process have large impact on the welded joint’s strength. This paper examines the impact of control parameters on the ultimate tensile strength (UTS) and percentage elongation (EL) of Inconel-600 plates, which are welded via MHH. Design of experiments was carried out in accordance with Taguchi L16 orthogonal array (OA), taking in consideration of filler powder particle size (FPS), susceptor and separator. Multi-performance features were optimized via the effective utilization of Taguchi-based grey relational analysis (GRA) approach. ANOVA results show that the predominating factor to govern the joint strength is FPS followed by the susceptor and separator. The validation experiments are performed on the predicted optimized setting of process parameters. First level of FPS (30μm), second level of susceptor (Graphite) and second level of separator (SiC) were found as the optimized parametric settings.
Challenges in joining of metallic pipes using microwave hybrid heating
