Ti5Si3/β-Ti nano-core–shell structure toughened glassy Ti alloy matrix biocomposites

Abstract

In the experiment, Ti₇₅Zr₁₁Si₉Fe₅ and Ti₆₆Zr₁₁Si₁₅Fe₅Mo₃ ingots were prepared by vacuum arc-melting furnace. Both Ti alloy ribbons of 3–5 mm in width and about 80 μm in thickness were made from bulk samples by an as-quenched technique under an argon atmosphere. Both melt-spun glassy ribbons exhibit large supercooled liquid regions, high reduced glass transition temperatures, and good thermal stabilities. For both alloys, the stable phases after heating are a Ti glassy matrix and in situ nano-Ti₅Si₃ particles encircled by nano shell of β-Ti. After the Ti₅Si₃/β-Ti nano-core–shell structure was in situ formed, in situ Ti₅Si₃/β-Ti nano-core–shell structure toughened glassy Ti alloy matrix composites were prepared. For the Ti₆₆Zr₁₁Si₁₅Fe₅Mo₃ ribbons, its high strength is attributed to both Mo solution strengthening and nano core–shell Ti₅Si₃/β-Ti toughening and dispersion strengthening. Observations and analysis on microstructure and fracture morphology of melt-spun glassy ribbons indicated that multi-slip bands were formed during the tensile test.