Effect of ternary alloying elements on microstructure and superelastictity of Ti–Nb alloys

• Published in: Materials science & engineering. A, Structural materials : properties, microstructure and processing Structural materials : properties, microstructure and processing, 2013-01, Vol.559, p.706-710
• Main Authors: Zhang, D.C., Mao, Y.F., Li, Y.L., Li, J.J., Yuan, M., Lin, J.G.
• Format: Article
• Language: English
• Subjects: Applied sciences; Elasticity. Plasticity; Exact sciences and technology; Mechanical properties; Mechanical properties and methods of testing. Rheology. Fracture mechanics. Tribology; Metals. Metallurgy; Microstructure; Superelasticity; Titanium alloys; β phase stability
• ISSN: 0921-5093; 1873-4936
• DOI: 10.1016/j.msea.2012.09.012

The effect of ternary alloying elements (X=Ta, Fe, Zr, Mo, Sn and Si) on the microstructure, the mechanical properties and the superelasticity of Ti–-22Nb–X alloys were investigated. The 1% addition of a ternary alloying element (X=Ta, Fe, Zr, Mo, Sn and Si) has a slight influence on the microstructure of the Ti–22Nb alloy. All the alloys after solution-treatment at 1073K for 1.8ks contain β and α″ phases. The elements of Sn, Si, Fe and Ta with a high number of valence electrons or a small atomic size have a strong solid–solution strengthening effect to the β phases in the alloys and the alloys with high Md¯ and low Bo¯ exhibit low elastic moduli. All the alloying elements improve the superelasticity of Ti–22Nb–X alloys. The elements, Fe, Mo, Sn and Si, which are with a high number of valence electrons and a small atomic size, strongly increase σSIM of the Ti–22Nb alloy.