中国物理B ›› 2021, Vol. 30 ›› Issue (5): 54702-054702.doi: 10.1088/1674-1056/abd75e

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Impact mechanism of gas temperature in metal powder production via gas atomization

Peng Wang(汪鹏)1,2, Jing Li(李静)1,2,‡, Xin Wang(王欣)1,2, Bo-Rui Du(杜博睿)1,2, Shi-Yuan Shen(申世远)1,2, Xue-Yuan Ge(葛学元)1,2,§, and Miao-Hui Wang(王淼辉)1,2,†   

  1. 1 State Key Laboratory of Advanced Forming Technology and Equipment, China Academy of Machinery Science & Technology, Beijing 100083, China;
    2 Beijing National Innovation Institute of Lightweight Ltd, Beijing 100083, China
  • 收稿日期:2020-10-22 修回日期:2020-12-24 接受日期:2020-12-30 出版日期:2021-05-14 发布日期:2021-05-14
  • 通讯作者: Miao-Hui Wang, Jing Li, Xue-Yuan Ge E-mail:wangmh@camtc.com.cn;lijing2012@buaa.edu.cn;gexueyuan@163.com
  • 基金资助:
    Project supported by the Open Fund of State Key Laboratory of Advanced Forming Technology and Equipment (Grant No. SKL2019006) and the National Natural Science Foundation of China (Grant No. 51975240).

Impact mechanism of gas temperature in metal powder production via gas atomization

Peng Wang(汪鹏)1,2, Jing Li(李静)1,2,‡, Xin Wang(王欣)1,2, Bo-Rui Du(杜博睿)1,2, Shi-Yuan Shen(申世远)1,2, Xue-Yuan Ge(葛学元)1,2,§, and Miao-Hui Wang(王淼辉)1,2,†   

  1. 1 State Key Laboratory of Advanced Forming Technology and Equipment, China Academy of Machinery Science & Technology, Beijing 100083, China;
    2 Beijing National Innovation Institute of Lightweight Ltd, Beijing 100083, China
  • Received:2020-10-22 Revised:2020-12-24 Accepted:2020-12-30 Online:2021-05-14 Published:2021-05-14
  • Contact: Miao-Hui Wang, Jing Li, Xue-Yuan Ge E-mail:wangmh@camtc.com.cn;lijing2012@buaa.edu.cn;gexueyuan@163.com
  • Supported by:
    Project supported by the Open Fund of State Key Laboratory of Advanced Forming Technology and Equipment (Grant No. SKL2019006) and the National Natural Science Foundation of China (Grant No. 51975240).

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摘要： This paper aims at studying the influence mechanism of gas temperatures (300 K, 400 K, 500 K, and 600 K) on gas atomization by simulating the integral atomization process of the close-coupled nozzle in vacuum induction gas atomization (VIGA). The primary atomization is simulated by the volume of fluid (VOF) approach, and the second atomization is studied by the discrete phase model (DPM) combined with the instability breakage model. The results show that, at an increased gas temperature, the influences of gas-liquid contact angle and gas temperature in the recirculation zone on the primary atomization are virtually negligible. However, increasing the gas temperature will increase the gas-liquid relative velocity near the recirculation zone and decrease the melt film thickness, which are the main reasons for the reduced mass median diameter (MMD, d50) of primary atomized droplets. During the secondary atomization, increasing the gas temperature from 300 K to 600 K results in an increase in the droplet dispersion angle, which is beneficial to the formation of spherical metal powder. In addition, increasing the gas temperature, the positive effect of gas-liquid relative velocity increase on droplets refinement overweighs the negative influence of the GMR decrease, resulting in the reduced MMD and diameter distribution interval. From the analysis of the atomization mechanism, the increase in atomization efficiency caused by increasing the temperature of the atomizing gas, including primary atomization and secondary atomization, is mainly due to the increase in the gas drag force difference between the inner and outer sides of the annular liquid film.

关键词: metallic powders, VIGA technology, argon temperature, two-phase flow

Abstract: This paper aims at studying the influence mechanism of gas temperatures (300 K, 400 K, 500 K, and 600 K) on gas atomization by simulating the integral atomization process of the close-coupled nozzle in vacuum induction gas atomization (VIGA). The primary atomization is simulated by the volume of fluid (VOF) approach, and the second atomization is studied by the discrete phase model (DPM) combined with the instability breakage model. The results show that, at an increased gas temperature, the influences of gas-liquid contact angle and gas temperature in the recirculation zone on the primary atomization are virtually negligible. However, increasing the gas temperature will increase the gas-liquid relative velocity near the recirculation zone and decrease the melt film thickness, which are the main reasons for the reduced mass median diameter (MMD, d50) of primary atomized droplets. During the secondary atomization, increasing the gas temperature from 300 K to 600 K results in an increase in the droplet dispersion angle, which is beneficial to the formation of spherical metal powder. In addition, increasing the gas temperature, the positive effect of gas-liquid relative velocity increase on droplets refinement overweighs the negative influence of the GMR decrease, resulting in the reduced MMD and diameter distribution interval. From the analysis of the atomization mechanism, the increase in atomization efficiency caused by increasing the temperature of the atomizing gas, including primary atomization and secondary atomization, is mainly due to the increase in the gas drag force difference between the inner and outer sides of the annular liquid film.

Key words: metallic powders, VIGA technology, argon temperature, two-phase flow

中图分类号:  (Kinetic theory of gases)

  • 47.45.Ab
75.47.Np (Metals and alloys) 81.20.Ev (Powder processing: powder metallurgy, compaction, sintering, mechanical alloying, and granulation) 47.55.df (Breakup and coalescence)