Ref.: MmeCa09-055

TiNiCuNb alloy produced by fast-cooling vacuum suction-casting for elastocaloric cooling applications

Apresentador: Jéssica Dornelas Silva

Autores (Instituição): Dornelas Silva, J.(Universidade Federal de Minas Gerais); Martins, S.(Universidade Federal de Minas Gerais); de Arruda Santos, L.(Universidade Federal de Minas Gerais); Silva dos Santos, D.(COPPE/Universidade Federal do Rio de Janeiro); Tadeu Lopes Buono, V.(Universidade Federal de Minas Gerais);

Resumo:
TiNiCu-based alloys have been explored for use as elastocaloric materials. In this study, a Ti48Ni38Cu10Nb4 alloy was produced via arc melting followed by vacuum-suction casting (VSC). In comparison to the material that was only arc-melted, a refined and more uniform microstructure was obtained via VSC. Differential scanning calorimetry (DSC) and tensile cyclic analyses were employed to evaluate the martensitic transformation temperature, enthalpy, and mechanical hysteresis. An ideal coefficient of performance (COPmat) of 44.5 was calculated by dividing the martensitic transformation enthalpy with the energy dissipated during isothermal uniaxial load/unload tests up to 1.5% strain. A stable mechanical behavior with a decreased hysteresis (144 kJ/m3) was observed within superelastic cycles performed at 2 × 10-3 s-1. No relevant effects on the martensitic transformation temperatures were observed after mechanical cycling. These results suggest a promising potential in developing a TiNiCuNb alloy by a fast-cooling process, such as suction-casting, to be used as an efficient and stable material for elastocaloric cooling.