Mono-disperse spherical Cu–Zn powder fabricated via the low wettability of liquid/solid interface

Spherical Cu–Zn alloy powders were fabricated by combining the surface tension of a molten metal with the de-wetting of a metal droplet on a graphite surface. The effect that the gas pressure had on the surface morphology and composition was studied. The Zn concentration can be maintained at 20.18 wt.%, 15.5 wt.% and 12.08 wt.% using 0.22 MPa, 0.10 MPa, and 0.04 MPa, respectively, from a commercially available Cu–38 wt.%Zn raw material. The gas pressure was adjusted to control the surface volatility of Zn without affecting the spherical morphology, and higher gas pressure yielded less volatile Zn. The Cu–Zn alloy powders were perfectly spherical, even at a negative pressure of 0.04 MPa. The spherical Cu–Zn alloy particles hardly changed and were fully dense up to Cu–50 wt.%Zn, which allowed high-quality spherical Cu–Zn alloy powders to potentially serve a large composition range.