Mechanical and Corrosion Properties of Ultrafine-Grained TC4-0.55Fe Alloy Processed by Equal-Channel Angular Pressing

This study investigates the effects of multi-pass Equal-Channel Angular Pressing (ECAP) on the mechanical and corrosion properties of TC4-0.55Fe alloy through room-temperature tensile tests, electrochemical experiments, SEM, and EBSD characterization. The results demonstrate that, with increasing ECAP passes, the average grain size is progressively refined from the initial 3.8 μm to 1.8 μm after four passes. After four passes, the yield strength and ultimate tensile strength increase from initial values of 906 MPa and 939 MPa to 995 MPa and 1022 MPa, respectively, while the elongation at fracture slightly decreases to 12.0%. Electrochemical corrosion results reveal that ECAP processing significantly enhances the corrosion resistance of the TC4-0.55Fe alloy. Specifically, the two-pass specimen exhibits nearly an order-of-magnitude reduction in both corrosion rate and self-corrosion current density compared to the initial state. The simultaneous improvement in strength and corrosion resistance is primarily attributed to the synergistic effects of grain refinement, increased dislocation density, and the evolution of basal texture.