Optimization of Process Parameters by Taguchi Grey Relational Analysis in Joining Inconel-625 Through Microwave Hybrid Heating

The quality of welded joints developed using microwave hybrid heating (MHH) technique is largely influenced by properties of the constituents employed in the process. This article investigates the influence of process parameters on tensile strength and flexural strength of Inconel-625 plates welded through MHH. Experiments were planned according to Taguchi L-16 orthogonal array by considering three factors: separator, susceptor and filler powder particle size. Ultimate tensile strength and flexural strength of the specimens welded at 600 and 900W were chosen as response characteristics. Application of Taguchi-based GRA has been effectively used to optimize multi-performance characteristics of the process. ANOVA results indicate that size of interface filler powder is the most significant factor in determining the joint strength followed by separator and susceptor. Further to corroborate the optimal parameter setting for maximum strength values, metallurgical characterization of the specimens is carried out through XRD and SEM. Specimens processed at 600W exhibited superior properties compared to their counterparts developed at 900W.