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Glass forming ability (GFA) is critically important for large-scale processing and application of bulk metallic glasses (BMGs). It is now widely accepted that the compositions of BMGs with excellent GFA can be located in off-eutectic regions, where the melts have high stability and primary crystallization plays an important role. In this study we reported that the thermodynamic properties of Ti32.8Zr30.2Cu9Fe5.3Be22.7, Ti32.8Zr30.2Cu9Co5.3Be22.7 and Ti32.8Zr30.2Cu9Ni5.3Be22.7 BMGs to understand the origin of the GFA in these glass-forming systems. It is present that these off-eutectic TiZr-based alloys have high thermomechanical stability and the GFA can be improved by manipulating the primary crystallization through minor alloying. The icosahedron-like short-range ordered arrangement improves the stability of the supercooled liquid, and the (Ti, Zr)2M phase with complex structure formed by minor alloying slows down the nucleation and growth of crystal phase, synergistically contributing to better GFA.

In this study, dry sliding tribological properties of a TiZr-based alloy with the chemical composition Ti-20Zr-6.5Al-4V (wt.%) were tested in air and vacuum under different normal loads (10, 20, and 30 N) at various sliding velocities. Results showed that the coefficient of friction in air was lower than that in vacuum, whereas the wear volume at sliding velocity presented an opposite trend. The surfaces and cross-sectional morphology of wear scar on the TiZrAlV alloy was analyzed through scanning electron microscopy to determine the wear mechanisms. The observations showed that abrasive wear and delamination wear were dominant in air. In vacuum, the main wear mechanism changed from slightly abrasive and adhesive wear to severe adhesive wear and delamination wear as the normal load increased. Wear mechanism maps were also constructed and compared. The comparison showed that severe wear (including delamination wear) was prevalent in air. [ABSTRACT FROM AUTHOR]

Development of shape memory alloys is always one of the most important directions for functional Ti alloys. The Ti-Zr-Mo series alloys with various Mo contents were prepared. The main aim of the current work is to investigate the effects of Mo on martensitic transition and shape memory effect of Ti-Zr alloy. The X-ray diffraction and transmission electron microscope results indicate that the phase constitution of the examined alloys is greatly dependent on Mo content. The Ti-Zr-Mo alloy with 2 wt% Mo is composed mainly of α′ martensite and a few β phase. As the Mo content increased to 4 wt%, the Ti-50Zr-4Mo alloy consists of α″ martensite and β phase. As the Mo content further increased to 8 wt%, the alloy consists mainly β phase and a barely detectable amount of α″ martensite. Thermal analysis shows that the reverse martensitic transition temperature of the examined alloys decreases with the increasing of Mo. The reverse martensitic transition start, A s , temperature is approximately 584 °C for Ti-50Zr-2Mo alloy and 519 °C for Ti-50Zr-4Mo, respectively. And the martensitic transition start, M s , temperature is approximately 553 °C and 501 °C for that two alloys, respectively. But no obvious exothermic and/or endothermic peak can be observed in DSC curve of Ti-50Zr-8Mo alloy. Furthermore, the effect of Mo content on shape memory recovery ratio, η , of the examined alloys was also investigated. Results show that the η first increases and then decreases with the increasing of Mo. The alloy with 4 wt% Mo has the maximum η approximately 13.8%. The influencing mechanism of Mo content on shape memory effect of the examined alloys was also discussed. This findings not only supplied a series of shape memory TiZr-based alloys, but also enriched and deepened the theory of shape memory effect. [ABSTRACT FROM AUTHOR]

The microstructure and texture component of plastic deformed metal and alloys show remarkable effects on properties and processing technique. In this work, the microstructural and textural evolutions of Ti 51.9 Zr 34.6 Al 10 V 3.5 alloy (at.%) under various rolling treatments were investigated. XRD and TEM results showed that the phase constitution of all heavy-rolled specimens are α″ martensite and β phase. In addition, the fraction of martensite increased with rolling reduction. Crystal orientation analysis showed that the orientation of hot-rolled specimen was dispersed. After cold rolling, crystals in specimens showed obvious preferred orientation, and aggregation degree increased with rolling reduction. However, preferred orientation in various cold-rolled specimens was different. The major texture component changed from {111}〈112〉 for 60% cold rolled specimen to {111}〈110〉 for 80% thickness reduction. Furthermore, the effects of intermediate annealing on microstructure and texture were also investigated. Results showed that the intermediate solution treatment weakened the rolling effects on microstructural and textural evolutions. The mechanism of microstructural and textural evolution was also discussed. Our findings can further elucidate the microstructural evolution theory of metal and alloys and can serve as a basis for adjusting and controlling the microstructure and properties of TiZr-based alloys with high performance. [ABSTRACT FROM AUTHOR]