A new strategy for synthesizing spherical powder of heterogeneous Mo-Cu pseudo-alloy

Preparing heterogeneous composite spherical powders with significant melting point differences and immiscibility properties, which can be used in fields such as additive manufacturing and injection molding, is a key challenge. In this work, a rational powder metallurgy-assisted rotating electrode atomization strategy was developed to synthesize Mo₇₀Cu₃₀ pseudo-alloy spherical powders with well-controlled morphology and microstructure. A dense Mo-Cu rod precursor, prepared via infiltration of 5–10 μm molybdenum and copper powders, enabled stable atomization and droplet formation under optimized conditions. The resulting powders exhibited an exceptionally high sphericity (≈99.5%) and particle size distribution in the range of 40–100 μm. Microstructural characterization revealed a homogeneous spatial distribution of Mo and Cu phases, accompanied by the formation of a Cu₃Mo intermetallic phase, indicative of non-equilibrium interfacial reactions during rapid solidification. The powders further demonstrated excellent flowability, high apparent density, and low oxygen content. Mechanistic analysis of the spheroidization process elucidated the interplay between droplet dynamics, phase evolution, and solidification behavior in immiscible, high-melting-point-difference systems. This work establishes a generalizable pathway for engineering heterogeneous pseudo-alloy spherical powders.