Influence of Heat Treatment on Microstructures and Textures of Hot-Extruded Ni47Ti44Nb9 Shape Memory Alloy Tubes
Microstructures and textures of the hot forged bar and hot-extruded tubes of Ni47Ti44Nb9 alloy as well as influence of heat treatment on them were studied in order to obtain a desired preferred orientation along the tube radial direction. The results show that B2 phase in hot-extruded tubes has a fine fibred shape and the main texture components are close to γ-fibre. Many fine recrystallized grains are formed for tubes heat treated at 600°C and γ-fibre is enhanced, which is beneficial to improving shape memory performances along the tube radial direction. Grain growth occurs at 850°C, and strong texture components deviate from γ-fibre.
Y. Yan et al., "Influence of Heat Treatment on Microstructures and Textures of Hot-Extruded Ni47Ti44Nb9 Shape Memory Alloy Tubes", Advanced Materials Research, Vol. 214, pp. 286-290, 2011