Abstract: Aiming at exploring the complex relationship between vacuum induction gas atomization (VIGA) process parameters and particle sizes of superalloy powders， the ANSYS-Fluent software was used to simulate the breaking behavior of droplets during the GH4169 superalloy VIGA process. The influence of atomization pressure on the atomization process and particle size distributions of the melt metal was analyzed. The results showed that the thickness of the strip-shaped liquid film and the droplet area in the first atomization process gradually decreased， while the crushing effect of the secondary atomization on the melt was gradually enhanced. The particle size of the atomized powders was reduced from 81.10 to 69.80， 64.77， 52.30 and finally to 41.80 μm. Correspondingly， the yield of fine powders was gradually improved from 1.72% to 12.62%， 18.89%， 56.50%， and finally to 71.54%.

Key words: vacuum induction melting, superalloy, gas atomization, atomization pressure, particle size distribution