Investigation of droplet transfer behaviours in cold metal transfer (CMT) process on welding Ti-6Al-4V alloy

Ti-6Al-4V alloy is widely used in the aeroengine industry due to its excellent comprehensive mechanical properties. In this paper, the droplet transfer behaviours of cold metal transfer (CMT) welding Ti-6Al-4V alloy have been studied by analysing captured electrical waveforms and high-speed images of droplet transfer process. The results indicated that the current and voltage waveforms of CMT welding Ti-6Al-4V alloy are different from that of typical CMT cycle. A current pulse appears in short-circuit phase to adjust energy distributions of different stages, and it results in smoother droplet transfer process. Frequency of droplet transfer increases with augment of wire feed rate or decrease of inductance correction value. Droplet size is greater with high wire feed rate or small inductance correction value.