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Plasma Sci. Technol. ›› 2018, Vol. 20 ›› Issue (1): 14019-014019.doi: 10.1088/2058-6272/aa8e94

• 18届全国等离子体科学和技术会议 • 上一篇    下一篇

Study on the RF inductively coupled plasma spheroidization of refractory W and W-Ta alloy powders

Chenfan YU (余晨帆)1, Xin ZHOU (周鑫)2, Dianzheng WANG (王殿政)1, Neuyen VAN LINH1 and Wei LIU (刘伟)1   

  1. 1 School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People’s Republic of China
    2 Science and Technology on Plasma Dynamics Lab, Xi’an 710038, People’s Republic of China
  • 出版日期:2017-12-04 发布日期:2017-12-07

Study on the RF inductively coupled plasma spheroidization of refractory W and W-Ta alloy powders

Chenfan YU (余晨帆)1, Xin ZHOU (周鑫)2, Dianzheng WANG (王殿政)1, Neuyen VAN LINH1 and Wei LIU (刘伟)1   

  1. 1 School of Materials Science and Engineering, Tsinghua University, Beijing 100084, People’s Republic of China
    2 Science and Technology on Plasma Dynamics Lab, Xi’an 710038, People’s Republic of China
  • Online:2017-12-04 Published:2017-12-07

Abstract:

Spherical powders with good flowability and high stacking density are mandatory for powder bed additive manufacturing. Nevertheless, the preparation of spherical refractory tungsten and tungsten alloy powders is a formidable task. In this paper, spherical refractory metal powders processed by high-energy stir ball milling and RF inductively coupled plasma were investigated. By utilizing the technical route, pure spherical tungsten powders were prepared successfully, the flowability increased from 10.7 s/50 g to 5.5 s/50 g and apparent density increased from 6.916 g cm−3 to 11.041 g cm−3. Alloying element tantalum can reduce the tendency to microcrack
during tungsten laser melting and rapid solidification process. Spherical W-6Ta (%wt) powders were prepared in this way, homogeneous dispersion of tantalum in a tungsten matrix occurred but a small amount of flake-like shape particles appeared after high-energy stir ball milling. The flake-like shape particles can hardly be spheroidized in subsequent RF inductively coupled plasma process, might result from the unique suspended state of flaky particles under complex electric and magnetic fields as well as plasma-particle heat exchange was different under various turbulence models. As a result, the flake-like shape particles cannot pass through
the high-temperature area of thermal plasma torch and cannot be spheroidized properly.

Key words: selective laser melting, RF plasma spheroidization, tungsten powders

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