Compressive properties and microstructure evolution in NiTiNb alloy with mesh eutectic phase

Abstract Novel mesh eutectic composite microstructure in a NiTiNb alloy was prepared. The microstructure characteristics and deformation behavior at multiple scales were investigated in this study. The excellent mechanical performance and superelastic recovery of the produced Ni44Ti51Nb5 and Ni46Ti47Nb7 alloys are attributed to the formation of mesh composite structure during the eutectic reaction. Meanwhile, Finite Element Analysis and in-situ micropillar compression experiments were performed in resultant eutectic and NiTi regions to comprehensively verify the eutectic phenomenon. Impressively, martensite transformation was accelerated because multiple dislocations and the existence of nanoscale precipitates in the interface region lead to further improvement of mechanical properties and superelastic recovery. In addition, the mesh eutectic phase can impede the slippage migration, thereby significantly promotes the plasticity.