Abstract Scope |
A novel ultra-high strength steel alloy was gas atomized to produce powder feedstock for additive manufacturing. Charge alloys were inductively melted with Argon shrouding at a superheating temperature of 1800 °C, and subsequently gas atomized using Argon gas at a pressure of 2 MPa. Metal flow rate and bulk powder yield were optimized by controlling the degree of superheating, atomizing gas pressure, orifice diameter, and nozzle material type. As-atomized powders were characterized for microstructure, composition, phase constituents, particle morphology, size distribution, and flowability by using optical microscopy, electron microscopy, energy dispersive spectroscopy, X-ray diffraction, particle size analysis, and Hall flowmeter. Results are presented with due respect for phase transformations and microstructural development during rapid solidification of gas atomization. |