Spheroidisation of tungsten powder by radio frequency plasma for selective laser melting

ABSTRACT

The growing interest in additive manufacturing of refractory metals is accompanied by the demand on spherical refractory meal powders with good flowability. In this work, the particle size distribution, particle morphology, phase and extent of oxidation of the tungsten powders spheroidised by radio frequency (RF) plasma with different feeding rates were investigated using scanning electron microscopy, laser particle size analysis and X-ray diffraction. It was demonstrated that spherical tungsten powders with extremely fine flowability and high apparent density were obtained by the RF plasma spheroidisation technology. High-density tungsten samples with negligible defects were prepared with the spheroidised powders by selective laser melting. The results would help pave the way for solving the problems in customising refractory metal parts by additive manufacturing.

KEYWORDS:

• Tungsten
• radio frequency plasma
• spheroidisation
• select laser melting
• high density

Disclosure statement

No potential conflict of interest was reported by the authors.

ORCID

Chao Chen http://orcid.org/0000-0001-6897-2998

Additional information

Funding

The authors would like to acknowledge financial supports from the National Key R&D Program of China [grant number 2017YFB0305800], the National Natural Science Foundation of China [grant number 51602350], the China Postdoctoral Science Foundation [grant number 2017M610505], the Key R&D Program of Hunan Province, China [grant number 2016JC2003] and the fund of State Key Laboratory of Powder Metallurgy, Central South University.