An investigation of different parameters on the penetration depth and welding width of Ti-6Al-4V alloy by plasma arc welding

In this paper, the effect of plasma arc welding (PAW) process parameters on the mechanical properties and macro- and microstructure of Ti-6Al-4V alloy is discussed. These parameters including welding current, welding speed, and plasma gas orifice diameter have an effect on the weld bead depth and width. Macrograph results indicate that there is a certain range of welding electric current and welding speed in which full-penetration weld is obtained and weld beads are free from defect. Experimental results show that the specimen mechanical strength is favorable and comparable to those of the base material, but the sample elongation is low entirely. Moreover, the results indicate that using an optimum range of welding speed and current, which lead to decreased heat input, makes greater mechanical strength and better relative ductility. The fusion zone microstructure consists of martensite (alpha '), massive alpha (alpha(m)), acicular alpha, and retained beta phase.