ADVANCED MATERIALS & PROCESSES | MARCH 2025 22 such as titanium alloys as there is no contamination of the molten metals since there is no crucible for melting them. The newest, single-step proprietary plasma-assisted gas atomization systems provide these benefits and add other incentives. It is a semi-continuous process at the front end. Material powders to be reprocessed, sieved to size, and sold as a premium product. This closed, end-to-end loop has been dubbed “the circular metal economy”— and is one of the factors that can significantly lower costs by reusing the waste metal as a feedstock for producing powders. SINGLE-STEP PLASMAASSISTED PROCESS There are currently two incumbent types of powder manufacturing processes. One is gas atomizing, which relies on high-pressure gas jets; the other, plasma atomizing, which involves a plasma torch that brings higher energy, improved flow, and cleaner particles to the final powder product. Gas atomizing is a multistep process using induction melting at temperatures up to 3000°C. That is enough heat for melting most alloys made from a mix of mined, virgin, and reclaimed metals and alloys feedstock to produce good-quality spherical powders. Plasma atomization, on the other hand, uses multiple plasma jets to melt and atomize pre-alloyed material that feeds continuously into the plasma. The powder created is highly spherical and clean, i.e., satellite-free. Plasma atomization is particularly used for high melting alloys such as refractory alloys as the plasma temperatures are often more than 10,000°C. This method is also used for reactive metal alloys Fig. 1 — A sustainable, melt-to-powder process supports a circular metal economy, which can lower effective costs, increase speed and reliability of supplies, and reduce carbon and energy use. Fig. 2 — Solid metal bar ends like these are a starting point for creating high-quality metal powders. Through the atomization process, the metal is melted and transformed into a fine mist that rapidly solidifies into tiny particles.
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