Fig.7. Simulation results of the thermal field in the deposit during one layer single-track deposition(a, b) temperature distributions for 0.06 s after irradiation with 7.0 J/mm (Points A and B are located at the surface of the molten pool zone, points C and D are located at the top of HAZ, points E and F are at the boundary between the HAZ and already-deposited amorphous zone; Tm is the melting temperature, Tx is the onset crystallization temperature, Tg is the glass transition temperature)(c) continuous heating transformation (CHT)curves for Zr55 bulk metallic glass (BMG) according to thermal cycles at the boundaries (Curves 1~3 denote the temperature profiles during deposited the coarser powder with laser heat input of 7.0, 10.8 and 15.7 J/mm, curves 4~6 denote the temperature profiles during deposited the finer powder with different heat inputs) |