Influence of Atomizing Gas Pressure on Microstructure and Properties of Nickel Silicide Intended for Additive Manufacturing

Nickel silicides are crucial in advanced technology applications ranging from semiconductor devices to high-temperature materials. Gas atomization is a process that involves the formation of fine liquid droplets and their rapid cooling and solidification to make powder particles. The final microstructure and the properties of the particles are highly sensitive to the gas atomization process parameters. In the present study, gas atomization of NiSi12-wt% was performed at three different pressures (35, 40, and 45 bars) to optimize the particle size distribution for additive manufacturing applications. A comprehensive range of characterization techniques, including scanning electron microscopy, X-ray diffraction, particle size distribution measurements, light optical microscopy, and density measurements, was used to evaluate the microstructural features, phase composition, and density of the produced NiSi12-wt% powders. Higher atomizing gas pressures resulted in a finer particle size distribution due to improved molten droplet breakup, increased satellite formation, and a well-suited particle size distribution for additive manufacturing applications.