Abstract
Ti-Ni shape memory alloy (SMA) thin films are suitable for microactuators due to their large shape recovery strain and stress. In this study, rapidly solidified Ti-Ni-Cu SMA ribbons containing 10at% Cu and 25at%Cu were fabricated by melt-spinning method followed by systematic heat treatment at temperatures below 1173K. Deformation behavior and microstructures were investigated. It was found that the as-spun ribbons were amorphous regardless of alloy composition. Such amorphous ribbon showed a high value of yield stress at 1.35GPa. The decrease of crystallization temperature was confirmed when increasing Cu-content from 10at% to 25at%. However, transformation temperature increased about 40K by increasing Cu-content to 25at%. It was also found that the ribbons heat-treated below 1023K were brittle regardless of alloy composition, while the ductility was improved when heat-treat above 1073K. Transformation temperature hysteresis was reduced to 10K by adding Cu to the Ti-Ni binary alloy: this characteristic is suitable for enhancing cooling rate in microactuators.
Published Version
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call