Application of Grey Relational Analysis for Optimizing Weld Bead Geometry Parameters of Pulsed Current Micro Plasma Arc Welded AISI 304L Stainless Steel Sheets

Pulsed Current Micro Plasma Arc Welding (PCMPAW) is one of the most widely used welding processes in sheet metal manufacturing industry. In any fusion arc welding process, the weld bead geometry plays an important role in determining the mechanical properties of the weld, which helps to improve the weld quality. Moreover, the geometry of weld bead involves several simultaneous quality characteristics, such as front width, back width, front height and back height, which must closely be monitored, controlled and optimized. This paper presents the optimization of the PCMPAW process by using the grey relational analysis considering the aforementioned quality characteristics, which are of maximum front width and back width, also minimum front height and back height. In relation to this, experiments were performed under different welding conditions such as peak current, back current, pulse rate and pulse width using AISI 304L stainless steel sheets of 0.25mm thickness using Response Surface Method (RSM) based on Central Composite Design (CCD) experimental design. It was observed that optimal welding parameters were determined by the grey relational grade from the grey relational analysis and they were also verified through confirmation experiments.