Gyroid Triply Periodic Minimal Surface Lattice Structure Enables Improved Superelasticity of CuAlMn Shape Memory Alloy

Improving the shape memory effect and superelasticity of Cu-based shape memory alloys (SMAs) has always been a research hotspot in many countries. This work systematically investigates the effects of Gyroid triply periodic minimal surface (TPMS) lattice structures with different unit sizes and volume fractions on the manufacturing viability, compressive mechanical response, superelasticity and heating recovery properties of CuAlMn SMAs. The results show that the increased specific surface area of the lattice structure leads to increased powder adhesion, making the manufacturability proportional to the unit size and volume fraction. The compressive response of the CuAlMn SMAs Gyroid TPMS lattice structure is negatively correlated with the unit size and positively correlated with the volume fraction. The superelastic recovery of all CuAlMn SMAs with Gyroid TPMS lattice structures is within 5% when the cyclic cumulative strain is set to be 10%. The lattice structure shows the maximum superelasticity when the unit size is 3.00 mm and the volume fraction is 12%, and after heating recovery, the total recovery strain increases as the volume fraction increases. This study introduces a new strategy to enhance the superelastic properties and expand the applications of CuAlMn SMAs in soft robotics, medical equipment, aerospace and other fields.