Effect of arc behavior on Ti-6Al-4V welds during high frequency pulsed arc welding

Pulsed welding (20 kHz, 40 kHz) created arc constriction compared with conventional arc welding (CAW). The core region of the arc plasma increased by 43.7-51.5%, which was considered as the energy concentration. The arc force enhanced by 42.9-57.1%, compared with 2.8 mN of CAW. The arc behavior greatly impacted the characteristics of the Ti-6Al-4V welds. The microstructures and mechanical properties were optimized. The grain size decreased by about 30% in the fusion zone (FZ), and parallel martensite α′ can be found in the coarse grain region (CGR). The elongation increased by 68% (20 kHz) and 38% (40 kHz), and the area reduction rate increased by 180%. Frequencies at 20-40 kHz were found to be the best range for Ti-6Al-4V welding.