Amir Mostafaei, assistant professor of mechanical, materials, and aerospace engineering at Illinois Institute of Technology, has earned a five-year, $600,000 CAREER grant from the National Science Foundation to continue his research developing new powders for additive manufacturing.
“Over the past three years at Illinois Tech, my research team has been actively investigating this idea, overcoming setbacks, and persistently refining the scientific aspects of our proposed research,” he says. “This grant has opened new horizons in metal additive manufacturing by introducing a new class of feedstock for various powder-based additive manufacturing processes, including laser powder bed fusion, electron beam melting, and binder jetting.”
The goals of the research include enhancing powder-spreading dynamics through multimodal particles and a hybrid powder dispenser and improving laser-powder interaction and microstructure control. If successful, Mostafaei says the project outcomes may expand material choices, making production more cost-effective and sustainable across various additive manufacturing processes.
The initial step in powder-based additive manufacturing processes is powder production, which can be costly and energy-intensive. The limited availability of metal alloys as feedstock powder is a drawback compared to conventional manufacturing methods such as casting and forging.
In powder bed fusion additive manufacturing, spherical powders are spread over a bed and selectively melted to create objects layer by layer. With the rapid advancements in additive manufacturing technologies to secure domestic supply chains, there is increasing interest in adopting a wider range of powders. However, the prevailing method of atomization to produce spherical powder is costly, energy-intensive, and introduces trapped gas bubbles that can affect final build quality. Also, the efficiency of powder production is less than 30 percent.
Mostafaei proposes a method that converts static bar-stock into high-quality powder at room temperature while preserving the density, chemistry, and structure of the input material. This innovative technology employs attrition milling with a reciprocating cutter to achieve precise particle size distribution with a greater than 95 percent yield and producing pore-free powders with both near-spherical and non-spherical shapes. This new powder production method was developed by Metal Powder Works. Mostafaei has collaborated with John Barnes, CEO and founder of Metal Powder Works, since 2018 when he was a postdoctoral researcher at Carnegie Mellon University.
“Additive manufacturing practitioners have traditionally favored spherical powders for powder-based additive manufacturing to ensure high-density parts due to concerns about poor flow and uniformity with non-spherical powders,” Mostafaei says. “Alternative powder production methods are appealing to powder production companies, researchers, and additive manufacturing machine manufacturers because they can reduce costs and emissions, increase metal additive manufacturing feedstock availability, and promote sustainability.”
Mostafaei says his proposed method of using non-spherical powder in additive manufacturing could reduce costs by 50 percent, allow powder to flow more easily through spreaders, reduce defects in manufactured products, and expand materials choices.
“The innovative use of non-spherical powder combined with a non-contact powder spreader has the potential to revolutionize the additive manufacturing industry, enabling the production of virtually any powder material used in powder bed additive manufacturing systems,” Mostafaei says.
Mostafaei says his research team is currently engaged in research across all three additive manufacturing processes and has successfully demonstrated the production of complex-shaped parts using a wide range of materials such as steels, titanium, copper, and shape memory alloys utilizing non-spherical powders.
“The CAREER grant is particularly prestigious and will enable me to establish a five-year research program focused on advanced topics in materials science and manufacturing, with a lasting impact on research, education, and society,” Mostafaei says.
