Characterization of aeronautical engine parts welded with capacitor discharge welding technology

Abstract

Capacitor discharge welding (CDW) is analysed to repair aeronautical components made with Inconel 718 and Ti6Al4V alloys, currently used for compressor and turbine applications. The CDW process is a resistance welding technology; it makes use of high-intensity current pulses, discharged by large capacitors. The use of multipoint contact features allows us to reduce stress concentration effects at the weld toe, obtaining thin weld beads, and achieve good material continuity. Base material and as-welded specimens with the same heat treatment were welded, using different parameters, and mechanically tested; the weld bead extension and the microstructural aspect of the welds were finally analysed. The development of advanced technologies for aeronautical components repair is of particular interest and the structural performances at room and working temperatures for capacitor discharge welds have to be carefully studied.