Plasma Spheroidization of Alloy Powders

Plasma spheroidization is a thermal process in which irregularly shaped alloy powders are transformed into near-perfect spheres by exposure to a high-temperature plasma jet. Feedstock particles are injected into a plasma torch—either direct current or inductively coupled—where they undergo rapid heating, surface melting and brief residence in a molten state, before quenching and solidification. The outcome is a highly spherical powder with improved packing density, flowability and chemical homogeneity. Such powders are essential for powder-bed fusion and directed-energy deposition in additive manufacturing, yielding components with superior mechanical properties, reduced porosity and consistent layer deposition. Beyond additive manufacturing, spheroidized powders find application in thermal spraying, cold gas dynamic spraying and in the fabrication of high-performance catalysts and metal-matrix composites. Key process parameters include plasma power, gas composition, feed rate and torch design, all of which govern residence time, melting efficiency and particle cooling rates. By fine-tuning these variables, researchers can control particle size distribution, surface oxidation and internal microstructure, tailoring powders for specific industrial and biomedical uses. The global significance of plasma spheroidization lies in its ability to deliver uniform, high-purity powders that support critical sectors such as aerospace, automotive, energy and healthcare, while reducing material waste and enhancing sustainability in powder production.

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Plasma Spheroidization of Alloy Powders publication trend

The graph below shows the total number of articles in plasma spheroidization of alloy powders across all publications each year (not limited to Nature Index journals).

Technical terms

Plasma spheroidization: A process in which powder particles are melted and re-solidified in a plasma jet to form spherical shapes.

Flowability: The ease with which a powder flows under gravity, often measured by Hall or Carney flow tests.

Circularity: A dimensionless metric (0–1) quantifying how closely a particle’s cross-section approximates a perfect circle, with higher values indicating greater sphericity.

Inductively coupled plasma (ICP): A plasma generation technique using an alternating magnetic field to ionise process gas, providing a high-temperature environment for powder spheroidization.

References

1. Thermal Plasma Spheroidization and Characterization of Stainless Steel Powders Using Direct Current Plasma Technology. Plasma (2024).
2. Production of Spheroidized Micropowders of W-Ni-Fe Pseudo-Alloy Using Plasma Technology. Metals (2024).
3. Investigation on spheroidization of refractory tungsten powders by laminar DC plasma torch. Materials Research Express (2022).