Plasma arc fusion-pressure welding of Al-ZrO2 system composite synthesized by XD method

Abstract

In this paper, an Al-ZrO2 systemcomposite synthesized by XD method is welded by a new plasma arc fusion-pressurewelding method. Their joint forms and microstructures areinvestigated. The results show that the optimum process parameters for the Al-ZrO2System composite (?7mm)are as follows: welding current is 150Aand welding time is 2s, no adding filling materials, spring upset force is2.45N. There are no defects such as large gas pore, micro-hole, or incompletefusion in the joint. During the solidification of the molten pool, the meltedZr3Al grows fully along the minimum growing energy direction<110>, thus the slender stick precipitates of Zr3Al appear inthe weld. The joint form and the microstructure are affected by the processingparameters such as welding current. For example, a larger current will causethe defect of micro-hole in the joint.