Influence of Nb addition on the structure, microstructure, Vickers microhardness, and Young's modulus of new β Ti-xNb-5Mo alloys system

Abstract

New Ti alloys are being developed to obtain materials with better properties for biomedical applications. In order to avoid complications caused for the presence of Al and V ions in the blood stream, novel alloys have been developed without these two elements. Mo and Nb are two non-toxic β-stabilizing elements used in Ti alloys because they decrease the elastic modulus and improve corrosion resistance. Thus, this study investigated the influence of Nb addition in Ti-xNb-5Mo alloy (x = 0, 10, 20, 30 %wt) on microstructure, structure, and selected mechanical properties. The samples were characterized after annealing, and the results showed the decrease of α phase and growth of β phase with the addition of Nb. The ω phase in the alloy containing 20% Nb was also detected. The samples’ elastic modulus and microhardness tended to decrease with increasing of the β phase, except for the Ti–20Nb–5Mo alloy due to phase hardening ω. The average crystallite size of the α and β phases increased with the addition of Nb.

Keywords

• Ti alloys
• Niobium
• Molybdenum
• Vickers microhardness
• Young's modulus
• Microstructural analyses