Grain-anisotropied high-strength Ni6Cr4WFe9Ti high entropy alloys with outstanding tensile ductility

Abstract It is difficult to increase performance using traditional alloy design approaches based on limited optimized microstructures. A substantial increase in strength usually causes the failure of materials with reduced ductility. Here, we report a strategy to overcome this bottleneck by optimizing the grain orientation in alloy systems. Unlike conventional casting microstructure based on traditional concept, the processing involves a sub grain-level heat flow-orientation regulation technique, leading to an optimal microstructure of submicrometer grains with different orientations. Our approach can effectively resist microcrack initiation, propagation, and fracture, resulting in excellent tensile ductility of SLM-processed Ni6Cr4WFe9Ti alloy. This optimized grain orientation strategy offers a general method for additive manufacturing of crisscross orientations-strengthened materials with both high strength and ductility.