Local strain matching between Nb nanowires and a phase transforming NiTi matrix in an in-situ composite

This study investigated the local strain coupling between Nb nanowires and a phase transforming NiTi matrix in an in-situ composite system, which presents a unique metallurgical system in terms of load transfer and strain coupling between two components. It is found that embedded Nb nanowires experienced plastic deformations even globe applied strains are smaller than the elastic limit of nanowires. This is attributed to the discrete strain field of NiTi matrix which deforms via first order stress-induced martensitic transformation. The results imply new concept in controlling mechanical property of phase transforming alloy based composites by tailoring internal stress/strain coupling via small pre-deformation process.