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

In the present research, spherical WMo 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 WMo 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 WMo 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 WMo alloy with few pores could be fabricated by LPBF based on the spheroidized WMo alloy powder.