ERI: Additive Manufacturing of High-Temperature Medium-Entropy Alloy Metal Matrix Composites via a Laser Powder-Bed Fusion Process

Alloys composed of very high melting point elements in equal or near-equal atomic ratios, called refractory medium/high entropy alloys, have tremendous potential for high-performance materials innovation due to their unique mechanical, thermal, and chemical properties, surpassing the traditional superalloys. Fabrication of parts with these alloys employing conventional methods presents significant challenges. Laser-based metal additive manufacturing (AM) process is a promising route to build complex parts made of refractory alloys and metal matrix composites with minimal processing steps and dependence on supply chain. This Engineering Research Initiation (ERI) project aims to achieve high melting-temperature medium entropy alloys with thermal stability, high strength-ductility balance, and high wear resistance by direct alloying the constituent elements with laser-based AM processes. This project has the potential to transform the fabrication of alloys for extreme environments and operating conditions. The advanced manufacturing education and research opportunities associated with this project will facilitate creating a pipeline to graduate education through experiential learning. The student traineeship will contribute to the steady growth of the nation’s trained workforce and leadership for next-generation manufacturing and bring prosperity in the region. The outreach efforts will spread awareness of science, engineering and technology education in students and the community. The overarching goal of this research is to advance the understanding of material-process-structure-property relationships for additively manufactured new high-temperature ceramic reinforced metal matrix composites (MMC) of refractory medium entropy alloys (RMEA). There is a substantial knowledge gap in understanding how the AM process can influence the solid solution formation, element diffusion, phase evolution, and the resulting microstructural and mechanical properties of additively manufactured refractory medium/high entropy alloys. This research aims to investigate a single-step alloying process through the following main research tasks: 1) Perform alloying with laser powder-bed fusion AM using RMEA pure element powders and ceramic particles; and 2) Characterize the microstructure and mechanical properties of 3D printed RMEA and RMEA-MMC specimens. Upon successful execution, this project will enable the rapid discovery of novel high-performance alloys, leading to a transformative additive alloying approach. This advancement will enhance the fabrication of near-net-shape parts with next-generation high-temperature alloy composites for supersonic, nuclear, automotive, and defense applications. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.