A new sintering strategy for preserving powder microstructure to achieve high strength and ductility

In powder metallurgy, high strength hinges on preserving powder-derived microstructures, whereas uniform ductility requires robust interfacial bonding between powders. Reconciling these competing demands remains a significant challenge, as conventional techniques rely on high-temperature exposure to strengthen interfaces, which coarsens the microstructure. In this study, we propose a novel two-step, low-temperature spark plasma sintering (SPS) route to address this issue. An initial high-pressure densification followed by rapid secondary sintering collectively lowers the overall processing temperature, and enables a CoCrFeMnNi multi-principal element alloy to retain a fine-grain structure inherited from powders, ensuring high yield strength, while simultaneously enhancing interfacial compatibility. The resulting architecture promotes dislocation accumulation at interfaces, homogeneous strain distribution at the grain scale, and multiple slip activity within grains, culminating in exceptional uniform elongation. This strategy offers a general pathway for fabricating advanced multiscale nanostructured materials from powder precursors.