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

Abstract

The compressive deformation behavior and magnetic volume susceptibility were investigated for Au 2 CuAl 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 Au 2 CuAl, 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 ©111ª-type. The measured magnetic volume susceptibility was ¹2.7 © 10 ¹6 in Au 2 CuAl, hence, this alloy is judged to be metal-artifact-free in magnetic resonance imaging (MRI). The magnetic susceptibility increased up to +7.0 © 10 ¹6 with increasing Cu content.

On the design strategies for SMA-based morphing actuators: state of the art and common practices applied to a fascinating case study

“…Au-based biomedical [12][13][14][15] Ni-Ti-based medical instruments (medical implants, 16 stent, 17 orthodontics, 18 surgery, 19 rehabilitation devices 20 ), Aerospace devices (rotary actuators, 21 solar sail, 22 morphing wing 23 ) Cu-based 24 pipe couplings, 25 hydraulic fittings, 26 mechanical dampers, 27,28 energy dissipation devices, 29 textiles 30 Fe-based 31 fishplates for crane rails, 32 pipe couplings, 25 civil structures 33 (concrete reinforcement, 34 damping, 35 pre-stressing elements 36 ) aerodynamic devices. In particular, it can be noted that most of the devices are dealing with aircraft components, with specific regard to wings, and focusing on design, fabrication, testing and modeling aspects.…”