Effect of solution annealing and low temperature ageing on the micrestructures and superelastic behaviour of ti-50.at.%ni alloy

Abstract

In this study, a plate form of Ti-50.7 at % Ni was subjected to solution annealing at 800 °C and 900 °C for one hour followed by ageing at 300°C and 400°C for 4 hour respectively in order to Investigate the effect of solution annealing and low temperature ageing on the microstructures and superelastic behaviour. lt was found that the formation of Ti3Ni4 precipitates on the samples aged at 300°C and 400°C influences superelasticity differently. Increasing the testing temperature up to 38°C generally increases the superelasticity of samples for all heat treatment conditions compared to those tested at 22°C, however the sample solution annealed at 900°C give better superelasticity at 22°C due to excessive plastic deformation at higher temperature.