Influence of heat treatments on phase composite and mechanical properties of Ni47Ti44Nb9 alloy
(1. College of Materials Science and Engineering,
Tianjin University, Tianjin 300072, China;
2. Department of Materials Engineering,
Tianjin Institute of Urban Construction, Tianjin 300384, China)
Tianjin University, Tianjin 300072, China;
2. Department of Materials Engineering,
Tianjin Institute of Urban Construction, Tianjin 300384, China)
Abstract: The influence of heat treatments on the phase composite and mechanical properties of Ni47Ti44Nb9 alloy were investigated by using XRD, SEM, TEM and EDX. The results show that a diffusional transformation takes place when the alloy is heated over 850℃ for a long time, and a new precipitation (Ni,Nb)3Ti with an hcp structure can be found. The formation of the precipitation leads to an increment of microhardness and reduction in elongation.
Key words: Ni-Ti-Nb alloy; heat treatment; precipitation; (Ni, Nb)3Ti