Compressive Deformation Behavior and Magnetic Susceptibility of Au₂CuAl Biomedical Shape Memory Alloys

Abstract

The compressive deformation behavior and magnetic volume susceptibility were investigated for Au₂CuAl biomedical shape memory alloys in a compositional range from 25 to 45 mol%Cu. Compression tests revealed that the stress for martensite variant reorientation was 282 MPa in Au₂CuAl, and the value increased with the Cu content. On the other hand, the slip stress was higher at intermediate compositions. Moreover, intergranular fracture was suppressed during compressive deformation. Calculated antiphase boundary (APB) energies suggest the dissociation of superlattice dislocation, which leads to the active slip of 〈111〉-type. The measured magnetic volume susceptibility was −2.7 × 10⁻⁶ in Au₂CuAl, hence, this alloy is judged to be metal-artifact-free in magnetic resonance imaging (MRI). The magnetic susceptibility increased up to +7.0 × 10⁻⁶ with increasing Cu content.