New research combines niobium, titanium and zirconium using laser powder bed fusion.
Researchers from Xi’an Jiaotong University, Tianmushan Laboratory and the National University of Singapore have pioneered a new method for crafting an ultra-strong, ductile alloy using 3D printing technology.
Called NTZO, the oxygen-doped blend of niobium, titanium and zirconium was fabricated using laser powder bed fusion (L-PBF). Through this process, the researchers achieved a unique combination of strength and flexibility, making NTZO suitable for harsh environments, including both aerospace and medical applications.
While body-centered cubic medium-entropy alloys composed of refractory metals are known for their remarkable strength, traditional fabrication methods often yield products that are rigid and more likely to crack under pressure.
However, by introducing a small amount of oxygen into the alloy during the 3D printing process, the researchers discovered a way to boost both its strength and ductility. Such a combination of properties is highly desirable in superalloys that need to withstand extreme stress without breaking.
According to the researchers, the key is the 3D printing process itself. Layer by layer, as the alloy builds up, rapid solidification and thermal cycling produce unique microstructures. Unlike the columnar grain structures typically seen in traditional metal parts, the NTZO alloy printed with L-PBF incorporates a blend of tiny, equiaxed grains with columnar grains. This specialized grain pattern results in greater strength and greater ductility.
The researchers’ approach allows them to control microstructures more precisely to create metals that are stronger and more adaptable. Potential applications can be found anywhere materials must endure high stress or extreme temperatures. The researchers believe the fusion of 3D printing and innovative alloy chemistry could open doors to materials critical to the next generation of high-performance technologies.
Moving forward, the researchers plan to explore how factors such as thermal cycles and microstructural changes impact the alloy’s properties. With further refinements, they intended to enhance the L-PBF process and improve the reliability of refractory alloys.
The research is published in Materials Futures.
