Cermet is an important composite composed of ceramics and metals, which has widespread engineering applications but is notoriously known for its poor ductility. This work synthesizes freestanding cermet nanosheets through the reaction of high entropy alloy nanocrystals with the molecular structure of poly-vinyl alcohol, which results in a unique nanostructure consisting of metallic nanocrystals surrounded by complex amorphous ceramics. Atomic force microscopy indentation shows that such a high entropy alloy derived cermet is strong and tough at ambient temperature with a superb strength (∼3.2 GPa) and excellent ductility (∼50%), therefore overcoming the long-standing issue of brittleness facing conventional cermets.
Keywords: cermet; high entropy alloy; multiple phase nanostructure; strength ductility trade-off; ultrathin film.