Temperature monitoring and calibration in Ti–6Al–4V molten pool with pulsed arc welding

Real surface temperature of the molten pool was studied with an infrared image, and it was aim to evaluate the temperature filed with pulsed arc welding. A calculation and calibration algorithm were proposed with standard black body, thermocouple outside molten pool, solidus and liquidus temperature. The comparison between conventional DC and pulsed arc was discussed. The results proved that pulsed arc created molten pool efficiently with better roundness, and caused narrow surface HAZ. The surface temperature distributed uniformly on most area of the molten pool at 100A–10 kHz, meanwhile the average grain size decreased by 16.6%. The effect of pulsed arc was the domain for surface solidification. The divergent trend occurred at 200 A level, even so, the over expansion was weakened with 200 A–10 kHz.