Studies On Transformation And Shape Memory Behavior Of Cold Drawn Wires Of Ti-49.8Ni Alloy

In the numerous shape memory alloys, the TiNi shape memory alloy has the good mechanical properties, the superelasticity and the shape memory function to be able to attract much attention.This article plans to use cold drawing to improve the intensity of Ti-49.8at.%Ni alloy and the heat treatment to enhance its performance, and it provides reference for high performance TiNi alloy as well as other components.The experimental results are obtained in this thesis as below:There is no phase transformation in DSC hot cyclic process of the drawn Ti-49.8.%Ni alloy, the reason is that the inherent drawback density increases and the internal stress inhibits the transformation after cold drawing. After400℃-450℃annealing. Aâ†'Râ†'M occurs when temperature decreasing, with the annealing temperature increasing, the position and the characteristic of R transformation peak is basic invariable, martensitic and R transformation peak approaches gradually to the higher temperature area, transformation temperatures Ms and Mr rise. The elongation is not good at room temperature after annealing at low temperature. Annealing at higher temperature, the elongation δ has surpassed above100%. presented the very gentle plastic platform, plasticity was lower than the annealed alloy treated at low temperature obviously.