Pseudoelastic Behavior of Boron-Doped ?1 -Type Cu-Al-Be Shape Memory Alloys

Abstract

This paper examines the influence of 0-0.2 wt.%B-doping on the microstructure, mechanical properties, and pseudoelastic behavior of Cu-Al<inf>11.5</inf>-Be<inf>0.57</inf> shape memory alloys (SMAs). This microstructure study reveals that the addition of boron leads to significant grain refinement in ?<inf>1</inf>-type polycrystalline Cu-Al-Be SMAs. A maximum refinement size of 50 µm was achieved with the addition of 0.15 wt.%B. The fine-grained (Cu-Al<inf>11.5</inf>-Be<inf>0.57</inf>)-B<inf>0.15</inf> SMA with serrated grain boundaries exhibited the maximum enhancement of ultimate tensile strength, 744.65 ± 29.34 MPa, and ductility of 21.93 ± 0.56%. The fracture morphology revealed the transformation of intergranular to transgranular fracture in the SMAs with boron-doping. Maximum pseudoelasticity of 4% was achieved in the SMA with 0.15 wt.%B and suits as a damper in seismic applications. © 2021, ASM International.