Microstructure evolution in a severely cold-worked NiTi wire during ageing treatment: An in situ neutron diffraction study

Abstract

Cold-worked NiTi wire was subjected to ageing treatment, during which in situ neutron diffraction technique was employed to investigate the microstructure evolution in terms of crystallinity, precipitation, texture, grain size and microstrain. It was found that both heating and rapid cooling bring about significant change in microstructure, whilst precipitation process is dominant at high temperature. Besides, the approaches to extracting microstructural information, including texture, grain size and microstrain, from individual Time-Of-Flight neutron diffraction patterns are proposed and verified.