中国有色冶金

Vacuum induction melting and atomization technology (VIGA) is currently the mainstream technology for preparing high-performance spherical metal powders, but there is still a lack of systematic research on the process parameters of atomization Laval nozzles. This article designs an atomized Laval nozzle and uses CFD simulation to simulate the effects of atomization pressure, airflow injection angle, and guide pipe extension length on the atomization flow field structure, velocity distribution, and static pressure inside the guide pipe. The results indicate that an increase in atomization pressure can expand the shock wave region, and both the flow field velocity and the static pressure inside the guide tube increase; An increase in the angle of airflow injection can cause the stagnation point and Mach disk position to shift upward; The elongation of the extended length of the guide pipe causes a phenomenon of static pressure first decreasing and then increasing. Based on the above analysis, the optimal process parameters are determined as follows: air jet angle of 30° and guide pipe extension length of -2mm. And 316L stainless steel powder was prepared under an atomization pressure of 3MPa. The powder has a uniform particle size distribution, high sphericity, and an alloy powder collection rate of ≥90%, significantly improving the atomization efficiency and powder quality of VIGA technology.