Shape recovery performance of a (V, C)-containing Fe–Mn–Si–Ni–Cr shape memory alloy fabricated by laser powder bed fusion

Abstract

In the present work, a Fe–Mn–Si shape memory alloy containing V and C has been fabricated by laser powder bed fusion for the first time. A pronounced pseudo-elasticity compared to a similar alloy but conventionally manufactured is achieved after aging treatment, as a result of the fine microstructure developed during the process and of the evaporation of Mn. The formation of high precipitate densities is also responsible for the improved thermo-mechanical properties. The size and density of precipitates significantly vary with aging conditions and account for important variation in material's performance. A maximum pseudo-elasticity is observed in samples aged at 750 °C for 6 h. The recovery strain upon unloading exceeds the values achieved in the conventionally manufactured alloy by more than 50%.

Keywords

• Shape memory alloys
• Pseudo-elasticity
• Laser powder bed fusion
• Microstructure
• Precipitation