Ferritic alloys strengthened by β′ phase and nanosized oxide

Ferritic alloys, strengthened by precipitating dispersed NiAl intermetallic compound (β′) and nanosized oxides, were fabricated by mechanical alloying route. The particle size evolution, chemistry, and interfacial structure of the nanoprecipitates were investigated. The near spherical β′ phase with volume fraction of 17.9% and an average diameter of 124 nm was obtained. The oxide nanoparticles, with a particle size of 3-8 nm, were uniformly distributed in α-Fe matrix. Moreover, both the β′ phase and nanosized oxides were found to be coherent or semi-coherent with the matrix. The β/β′ Fe-based ODS alloys can be considered as a potential candidate for the replacement of γ/γ′ Ni-base ODS alloys.