Stability of ni-ti shape memory alloy wire during thermo-mechanical cycling using the joule heating effect
Walber Medeiros Lima1; Jackson de Brito Simões1; Rodinei Medeiros Gomes2; Cícero da Rocha Souto3; Tadeu Antônio de Azevedo Melo3; Carlos José de Araújo4
1 Rural Federal University of Semi-Arid - UFERSA; 2 Federal University of Paraíba - UFPB; 3 Federal University of Paraíba - UFPB; 4 Federal University of Campina Grande - UFCG
doi:10.20906/CPS/COB-2015-0945
Resumo
NiTi wires are widely used as thermomechanical actuators that are subject to repeated thermal cycling in a range a temperatures and fluctuating loads. The mechanical stability is a fundamental behavior that need to be understood to project well accurate actuators. Thus, basically the total recoverable strain must to be constant under certain external conditions. In this investigation an apparatus was built to monitor the recoverable strain during prolonged thermal cycles under a constant load. It has been shown that the recoverable strain decrease with cycling. Also, an acceptable stabilization can be found when the wires are heat at 750mA.
Palavras-chave: Shape memory alloy; Thermo-mechanical cycling; Mechanical stability