Selection of welding process to fabricate butt joints of high strength aluminium alloys using analytic hierarchic process

Selection of welding process is an unstructured decision problem involving multiple attributes (factors). To provide decision support for the welding or design engineer, an all encompassing analysis of multiple attributes is necessary. The present paper reports a new procedure using an analytic hierarchic process (AHP) for the selection of a welding process to fabricate butt joints of high strength aluminium alloy of AA 7075 grade, based on the qualitative factors of welding processes, when the quantitative factors appear to be equal. The following three welding processes from arc welding family are generally used to fabricate high strength aluminium alloys: (i) gas metal arc welding (GMAW), (ii) gas tungsten arc welding (GTAW), and (iii) plasma arc welding (PAW). Of the three available processes, the best process has been selected by doing qualitative analysis with the help of AHP and in the present case, for welding high strength aluminium alloy, the best process is GTAW.