In situ synthesis of spherical WMo alloy powder for additive manufacturing by spray granulation combined with thermal plasma spheroidization

Abstract In the present research, spherical W Mo alloy powder for additive manufacturing was successfully synthesized by spray granulation (SG) in combination with thermal plasma spheroidization (TPS). Firstly, W and Mo particles (1–3 μm) were banded together through SG and formed porous agglomerated powder with desired particle size distribution and flowability. The porous agglomerated W Mo powder was subsequently melted through thermal plasma, W and Mo dissolved together and formed solid solution accompanied with powder densification during TPS. Through optimization of the process conditions, the spheroidized W Mo alloy powder exhibits homogeneous element distribution, low oxygen content (~0.08%), and good flowability (10 s/50 g), which meet the demand for laser powder bed fusion (LPBF). Remarkably, nearly full dense W Mo alloy with few pores could be fabricated by LPBF based on the spheroidized W Mo alloy powder.