Making an Ultra-Ductile Laminate Medium Entropy Alloy by Pressure Thermal Treatment

Innovations in either high-performance materials or microstructures by conventional processing methods are often challenging to achieve without a synergistic combination. The perfect combination of pressure and temperature offers a great prospect for altering the microstructure that would permit achieving the extreme properties in functional and structural materials. Here, pressure thermal treatment is used to make a laminate medium-entropy alloy that exhibits a combination of a large fracture elongation of ≈122 percent and a high fracture strength of ≈900 megapascals. The high tensile ductility stems from the strong synergistic effects of the laminate structures with low-energy interfaces. Consequently, versatile dislocation configurations and deformation twinning are sequentially stimulated, effectively improving the alloy's ability to accommodate plastic deformation. This unique laminate structure with the low-energy interface obtained from pressure thermal treatment offers a paradigm for developing hierarchically metallic materials with exceptional mechanical properties.