In metal 3D printing, support structures can sometimes account for up to 50% of the billet volume. Together with defective parts, these high-value metal wastes cannot be returned to the production cycle due to difficulties in recycling. A research team from the National University of Science and Technology (NUST MISIS) has developed an ultrasonic atomization method that uses high-frequency vibrations of 50,000 times per second to "shake" waste metal into highly spherical powder, achieving a sphericity coefficient of 0.90 (with 1 being a perfect sphere), opening a new path for closed-loop recycling of additive manufacturing metal waste. The research results have been published in the JCR Q1 journal Journal of Manufacturing and Materials Processing.

The "Rich Waste" Challenge of 3D Printing

Metal additive manufacturing (i.e., metal 3D printing) is one of the core manufacturing technologies in fields such as aerospace, medical implants, and high-end molds. However, this technology has a "rich man's disease"—it generates a large amount of high-value metal waste.

During the metal 3D printing process, unmelted metal powder can be sieved and returned to the working cycle. However, two types of waste cannot be directly recycled:

Support structures: Must be added when printing complex parts, and in some cases can account for up to 50% of the billet volume

Defective parts: Failed substandard printed components

These wastes have exactly the same composition as the original powder and are extremely valuable—especially materials like titanium alloys, nickel-based superalloys, and even precious metals such as platinum. However, due to the complexity of recycling, they have long been discarded or downgraded, unable to return to the high-value production cycle.

Four Technical Breakthroughs of Ultrasonic Atomization

The NUST MISIS additive manufacturing laboratory team, led by graduate student and senior engineer Leonid Fedorenko and Olga Bashmakova, has adopted the ultrasonic atomization method to directly convert metal waste into high-quality printing powder.

Core Mechanism: Arc Melting + 50,000 Vibrations/Second Ultrasonic Vibration

The core principle of this technology is divided into three steps:

Arc Melting: Metal waste is melted under an electric arc to form a stream of liquid metal

Ultrasonic Atomization: The liquid metal stream flows downward onto a surface vibrating at a frequency of up to 50,000 times per second

Instant Solidification: The molten droplets instantly solidify in an argon protective atmosphere, forming tiny spherical powder particles

The key to this process is that the high-frequency ultrasonic vibration breaks the surface tension of the liquid metal, "shattering" it into uniform tiny droplets, which are rapidly cooled and shaped in the protective atmosphere.

Sphericity Leap: From "Potato" to "Marble"

Sphericity is a core indicator for measuring the quality of metal powder—the higher the sphericity, the better the powder's flowability and packing density during powder spreading.

The research team's experimental data is impressive:

Sphericity coefficient of recycled powder: Increased to 0.90 (with 1 being a perfect sphere)

Comparative advantage: Powder morphology prepared by traditional gas atomization is often irregular, while ultrasonic atomization technology can obtain highly spherical powder, theoretically helping to improve the density and mechanical properties of printed parts

Olga Bashmakova noted: "The sphericity of the recycled powder particles has significantly improved. The higher the sphericity coefficient of the powder material, the better its rheological properties and packing density during powder spreading in selective laser melting equipment."

Process Closed Loop: Waste → Powder → Printing → Waste

The ultimate goal of this technology is to close the production cycle of metal additive manufacturing. Through ultrasonic atomization, support structures and defective parts that could not previously be returned to the production cycle can be converted into high-quality spherical powder and re-enter the 3D printing process.

This means that a complete "waste → powder → printing → waste" closed-loop cycle system is expected to be established, fundamentally changing the resource utilization model of metal additive manufacturing.

Academic Endorsement: Published in Q1 Journal, Funded by the Russian Science Foundation

This research has been published in the JCR Q1 journal Journal of Manufacturing and Materials Processing and has received funding from the Russian Science Foundation (Project No. 25-79-10304).

From Common Alloys to Precious Metals

Phase One: Validation with Common Alloys

According to Stanislav Chernykhin, head of the NUST MISIS additive manufacturing laboratory, the technology is currently being validated on common alloys to demonstrate the effectiveness of the proposed approach.

Strategic Focus: Precious Metal Additive Manufacturing

The research team clearly stated that the new method will be particularly promising for recycling precious metal (e.g., platinum) additive manufacturing parts.

Precious metals like platinum are expensive and scarce, playing an irreplaceable role in fields such as aerospace, medical, and chemical engineering. If nearly 100% recycling of precious metal materials can be achieved through ultrasonic atomization, it will significantly reduce product costs in high-end manufacturing.

Industrialization Potential: Cost Reduction and Efficiency Improvement

Spherical metal powder is the core raw material for additive manufacturing, and its particle size, sphericity, and flowability directly affect the quality of printed parts. The large-scale application of this technology is expected to achieve:

Reduction in raw material costs for metal additive manufacturing

Promotion of the industrialization process of waste recycling and reuse

Reduction in dependence on primary metal resources

Talent Development: From Laboratory to Industry Frontline

Alexander Komissarov, Dean of the NUST MISIS Advanced Engineering School "Materials Science, Additive and Cross-Disciplinary Technologies," added: "Additive technology research is one of the key directions at NUST MISIS. From their first year, students operate real equipment, participate in scientific research, and engage in projects for the country's top enterprise groups."

This "laboratory-teaching-industry" trinity model provides a continuous stream of talent support for the ongoing iteration and industrial implementation of this technology.

Redefining the "Cost Equation" of Metal Additive Manufacturing

The deeper value of this technology lies in recalculating the full lifecycle cost of metal additive manufacturing. In the past, support structures and defective parts were considered "sunk costs"—expensive metal powder was invested but could not be recycled. Ultrasonic atomization gives these wastes a "second life," returning them to the production cycle with quality close to that of the original powder.

At a time when global critical metal resources are becoming increasingly strained and supply chain security is gaining attention, this technology provides a "key" for the metal additive manufacturing industry—unlocking the door to closed-loop recycling of high-value metal waste.

As demonstrated by the NUST MISIS team: When ultrasonic vibrations of 50,000 times per second "shatter" not just the surface tension of liquid metal, but also the traditional linear resource model of "extraction-manufacturing-disposal," metal additive manufacturing is evolving from a "high-cost precision art" to a "recyclable green manufacturing."