Microstructural and mechanical properties of β-type Ti–Mo–Nb biomedical alloys with low elastic modulus

• Published in: Journal of alloys and compounds 2020-01, Vol.815, p.152412, Article 152412
• Main Authors: Li, Peiyou, Ma, Xindi, Tong, Ting, Wang, Yongshan
• Format: Article
• Language: English
• Subjects: Alloys; Beta phase; Biomedical alloy; Biomedical materials; Elastic modulus; Elastic recovery; Functional materials; Impact resistance; Mechanical properties; Modulus of elasticity; Molybdenum; Nanoindentation; Niobium base alloys; Service life; Strain; Surgical implants; Titanium base alloys; Ti–Mo–Nb alloy; Wear resistance; β phase
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2019.152412

The microstructural and mechanical properties of β-type Ti74-xMoxNb26 (x = 0, 2, 4, 6, and 8 at.%) biomedical alloys with low elastic modulus were investigated. The experimental results show that the Ti74Nb26 alloy is composed of the β and α’’ phases; however, the Ti74-xMoxNb26 (x = 2, 4, 6, and 8 at.%) alloys are composed of only a single β phase. Based on the stress–strain curve, the Ti66Mo8Nb26 alloy with the large yield strength and elastic energy can consider as biomedical and functional materials. The Mo addition not only stabilizes the β phase of the alloys, but also increases the strength, and retains the ductility of the Ti74Nb26 alloy. Based on nanoindentation technique, the reduced elastic modulus (Er) of Ti66Mo8Nb26 alloy with the high hardness (H) is 54.5 GPa, which is 1.5–5.5 times of that of human bone (10–30 GPa), and is the smaller than that of commercial Ti–6Al–4V biomedical alloy (120 GPa). The wear resistance (H/Er) and anti-wear capability (H3/Er2) ratios of Ti66Mo8Nb26 alloy are 0.0591 and 0.0112 GPa, respectively, indicating that the good wear resistance and anti-wear capability, or long service life as biomedical materials, compared with those of CP-Ti alloy. In addition, the elastic recovery values of the Ti–Mo–Nb alloys are larger than that of CP-Ti alloy (20.4%), which indicates that the Ti–Mo–Nb alloys exhibit the higher impact resistance. •Ti–Mo–Nb alloys are mainly composed of β-Ti and α′′-Ti phases.•Ti66Mo8Nb26 alloy has the large yield strength and elastic energy.•Elastic modulus (54.5 GPa) of Ti66Mo8Nb26 alloy is close to that of human bone (10–30 GPa).•Large H/Er and H3/Er2 values indicate good wear resistance and anti-wear ability.