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

摘要

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 mu m 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 beta-Ti. After the Ti5Si3/beta-Ti nano-core-shell structure was in situ formed, in situ Ti5Si3/beta-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/beta-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.