|
|
|
| A review of research on powder prepared by gas atomization |
| ZHANG Xueliang1，2，TAO Yu1，2，JIA Jian1，2，QU Jinglong1，2 |
| 1. High Temperature Materials Research Institute，Center Iron and Steel Research Institute Co. ，Ltd，Beijing
100081，China； 2. GAONAAero Material Co. ，Ltd. ，Beijing 100081，China |
|
|
|
|
Abstract The research progress of gas atomization technology at home and abroad was summarized, including
the influence of gas atomization parameters on the powder characteristics, the numerical simulation of gas flow
structure, primary breakup of high-temperature melt and secondary breakup of droplets during gas atomization to
provide some references for the further improvement of gas atomization technology. The quality of powder is related
to the parameters of gas atomization. In a certain range, both increasing gas pressure, gas temperature, melt superheat
and decresing melt diameter, melt flow rate will cause the power size decrease and improve the yeild rate
of fine powder. The dynamic energy of atomization gas can be increased with increasing gas pressure and temperature,
which is benefit for the melt breakup. Meanwhile, increasing the melt superheat will make the viscosity and
surface tension of melt decrease, which will also promote the melt breakup. The gas atomization process is too
complex to analyze through the ordinary experimental methods, so numerical simulation becomes an important
way to describe the gas flow field, primary breakup of melt and secondary breakup of droplets during gas atomization
process. The simulation results indicate that the gas flow field is consisted of a series of“Prandtl Meyer”
waves, forming a“necklace-like”structure. The primary breakup of melt is mainly simulated by VOF (volume of
fraction) model. And the secondary breakup of droplets is well described using DPM (discrete phase model) modle
and the instability model of melt such as TAB model, KH model and KHRT model. Particle size distribution and
particle morphology are closely related to the parameters of gas atomization such as gas pressure, gas temperature,
melt superheat and melt flow rate. Selecting reasonable atomization parameter is the basis for preparing spherical
powder with high quality. At present, the research on the gas atomization process, including the gas flow field, primary
breakup of melt and secondary breakup of droplets, is mainly conducted by numerical simulation method.
The existing theoretical models and algorithms can realize the simulation of the gas atomization process, but the understanding of the interaction between different atomization stages is still blank. In order to realize the mutual coupling
analysis of different stages of the entire atomization process, optimizating the theoretical model and algorithm
of gas atomization is improtant in the furture study.
|
|
Received: 25 March 2021
|
|
|
|
|
|
|
2022, Vol. 32 
