Abstract: In this paper, the effect of electron beam smelting process on the surface quality of Ø100 Ta ingot is studied through experiment of adjusting the melting power at a fixed melting rate. The experiments results show that, when the melting speed is constant, the melting power is reduced, and the specific electrical energy is reduced, the surface of Ta ingots is prone to defects such as cold insulation and pinching. The melting power is too high, and the temperature of the molten pool is too high, resulting in overheating and overmelting. The microstructure is unfavorable and even produces severe metal tumor scars. When the vacuum of the electron beam melting furnace is 2×10^-2Pa, the melting speed is 30 kg/h, the melting power is 160kW, and the cooling time is 4h, which is beneficial to the diffusion and volatilization of impurity elements.

Key words: high pure Ta, electron beam melting process, melting power, surface quality of ingot