Abstract:The high-entropy shape memory alloy system Ti₂₅Zr₁₀Hf₁₅Ni₂₅Cu_25-xCo_x (x = 5, 10, 15 at.%) is prepared using the method of melting in a magnetic levitation water-cooled copper crucible and casting in a vacuum copper mold. The phase structure, microstructure, mechanical properties, and corrosion resistance of the alloys are tested and analyzed using XRD, SEM,EBSD, a mechanical testing machine, and an electrochemical workstation. The results indicate that the as-cast alloy exhibits a single-phase B2 austenite structure. With increasing Co content, the grain size first decreases and then increases. The compressive strength and plasticity of the system initially increase and then decrease with the increase of Co content. Additionally, there is a slight improvement in strength and plasticity as the size of the samples decreases. Among the alloys, the Ti₂₅Zr₁₀Hf₁₅Ni₂₅Cu₁₅Co₁₀ composition exhibits the best overall mechanical properties, with compressive strength and plasticity reaching 2694.65±2.3 MPa and 26.55±0.3%, respectively. In a 3.5 wt.% NaCl solution, the corrosion resistance of the alloy initially increases and then decreases as Co content increases.

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