| Summary: | Four novel superelastic alloys, Ti-41Zr-12Nb, Ti-42Zr-11Nb, Ti-43Zr-10Nb, Ti-44Zr-10Nb (at.%), were obtained and studied in terms of their microstructure and mechanical properties. The obtained alloys were subjected to thermomechanical treatment, providing alloys with a pronounced superelastic behavior. Materials phase composition and microstructure were studied using XRD and SEM methods. Based on the XRD results, maximum lattice strains in the <inline-formula><math xmlns="http://www.w3.org/1998/Math/MathML" display="inline"><semantics><mrow><msub><mrow><mfenced close="]" open="["><mrow><mn>011</mn></mrow></mfenced></mrow><mi>β</mi></msub></mrow></semantics></math></inline-formula> direction were calculated as 5.9%, 6.3%, 7.5%, and 7.2% for Ti-41Zr-12Nb, Ti-42Zr-11Nb, Ti-43Zr-10Nb, and Ti-44Zr-10Nb alloys, respectively. Mechanical properties of the thermomechanically-treated alloys were studied by Vickers microhardness testing, static tensile testing, and superelastic mechanical cycling. The maximum superelastic recovery strains attained at room temperature was 3.7%, 1.9%, 3.2%, and 3.0% for the Ti-41Zr-12Nb, Ti-42Zr-11Nb, Ti-43Zr-10Nb, and Ti-44Zr-10Nb alloys, respectively. Ti-41Zr-12Nb alloy demonstrated the highest ductility, with relative elongation to failure of over 20%, combined with the total recovery strain of more than 6%. Obtained results indicate that Ti-41Zr-12Nb is one the most promising alloys of the Ti-Zr-Nb system, with quite perfect superelastic behavior at room temperature.
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