Development of NiTiNb in-situ composite with high damping capacity and high yield strength

Abstract

The shape memory alloys are well known to exhibit high damping capacity in martensite state, but possess low yield strength because of the reorientation or de-twining of the martensite variants. The high damping mechanism of shape memory alloys was introduced. The NiTiNb alloys with high yield strength and high damping capacity were designed and prepared. The microstructure evolution, martensitic transformation behavior, damping capacity and mechanical properties of series NiTiNb alloys were investigated. In view of the microstructure characteristics of the NiTiNb in-situ composites, the mechanism associated with high damping capacity and high yield strength was discussed. The results show that NiTiNb alloys feature in in-situ composite, composed of primary NiTi(Nb) phase and fine lamellar eutectics of NiTi(Nb) and β-Nb.