Design of non-equiatomic low-density alloys inspired by modified high-entropy shape memory alloy

Abstract

The increasing demand for lightweight, high-performance materials in advanced structural applications has driven significant research into low-density high entropy alloys and shape memory alloys. This study focuses on the development and characterization of a non-equiatomic, low-density, multi-phase (Ti6Al4V)₅₀(Ni+Co)₅₀ alloy, inspired by modified high-entropy alloy design principles and optimized for advanced structural applications. The alloy exhibits a refined microstructure, a significantly reduced density of approximately 5.2 g/cm${}^3$ – lower than conventional nickel-based shape memory alloys and other low-density high-entropy alloys – and superior mechanical properties, including high compressive yield strength. Strain recovery experiments and DSC analysis also confirm shape memory characteristics, supporting its potential use in functional applications. These properties, combined with its printability in laser powder bed fusion (L-PBF), make the (Ti6Al4V)50(Ni+Co)50 alloy a candidate for additive manufacturing, exhibiting low porosity and minimal cracking during processing.