Microstructural characteristics and in situ reinforcement in NbC-doped Fe81Ga19 magnetostrictive alloys

Abstract

Abstract The microstructural phase distribution and the origin of mechanical enhancement of NbC-doped Fe–Ga magnetostrictive alloys are not very clear. In this study, a detailed investigation into the microstructural characteristics and their effects on the mechanical properties has been performed on NbC-doped Fe81Ga19 alloys. Increasing NbC causes remarkable grain refinement of the Fe-Ga alloy matrix. Rod-like NbC particles precipitating in Fe–Ga grain matrix and NbC dendrite clusters segregating at Fe–Ga grain boundaries are observed. As a result, NbCparticle / Fe81Ga19 and (NbCparticle + NbCdendrite) / Fe81Ga19 magnetostrictive composites are obtained. The mechanical properties are found to be significantly improved by combined effects of grain-refinement strengthening and precipitate reinforcement, generating a maximal tensile strength of 620 MPa and an elongation ratio of 0.9%.