Mechanical properties and corrosion behavior of precipitation-strengthened FeCoNi-Tix (x = 0, 3, 6 at. %) multi-principal element alloys

This study investigated the influence of adding different titanium contents (0, 3, 6 at. %) and controlling nanoscale L12-type Ni3Ti precipitates through hot-forge and heat treatment on the mechanical and corrosion behavior of FeCoNi medium-entropy alloys. It was found that, when the Ti atom is in a solid solution state, the degree of lattice distortion increases, and the corrosion resistance decreased with increasing Ti content. Whether in the solid solution state or the precipitate state, increasing the Ti content effectively enhanced the strength of FeCoNi alloy. The strengthening effect was particularly prominent in the precipitate state compared to the solid solution state. The experimental results provided valuable references for the design and preparation of other high-strength, tough, and corrosion-resistant multi-principal element alloys.