Thermal effect and cracking of laser additively manufactured tungsten

In this study, we compared the laser melting and direct energy deposition of tungsten using two kinds of lasers: femtosecond pulsed laser and fiber continue wave laser. It is evident that fs laser deposition can significantly reduce the average energy input to 30% of CW laser. This energy efficiency improvement is attributed to decreasing thermal dissipation and thermal residual stress in the area surrounding the melting pool. This reduction of energy input can effectively suppress the thermal stress and microcracks during solidification􀆟on and the ductile-brittle transition (DBT) transition.