Fusion and solidification processes of pulsed YAG laser spot welds Available to Purchase

Fusion and solidification processes of weld pool during and after the irradiation of pulsed YAG laser and their relation to evaporation (plume formation) phenomena were observed by high speed photographic methods such as laser strobe and high speed cinematography. When the beam spot was moderately defocused the fusion of targaet surface initiated soon after the laser shot and quickly increased its nugget diameter to the beam diameter. However, when the evaporation of molten surface took place the pool diameter was suppressed to increase perhaps due to the increase in scattering loss of incident beam by plume. After the decay of laser pulse energy the molten pool started rapid solidification from the periphery to center and the net solidification rate was estimated from the solidification rate of pool surface.