Effect of Ta addition on the electrochemical behavior and functional fatigue life of metastable Ti-Zr-Nb based alloy for indwelling implant applications

• Published in: Journal of alloys and compounds Vol. 748; pp. 51 - 56
• Main Authors: Ijaz, M.F., Zhukova, Y., Konopatsky, A., Dubinskiy, S., Korobkova, A., Pustov, Y., Brailovski, V., Prokoshkin, S.
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 05.06.2018; Elsevier BV
• Subjects: Alloying additive; Beta phase; Biocompatibility; Corrosion effects; Corrosion fatigue; Dependence; Electrochemical analysis; Fatigue; Fatigue life; Fatigue tests; Fracture mechanics; Fracture morphology; Materials fatigue; Melting; Microstructure; Niobium base alloys; Passive film; Protective coatings; Surgical implants; Tantalum; Thermomechanical treatment; Titanium alloys; Titanium base alloys; Vacuum arc melting; Zirconium; Fracture morphology; Titanium alloys; Fatigue; Passive film; Microstructure
• ISSN: 0925-8388; 1873-4669
• DOI: 10.1016/j.jallcom.2018.03.033

In this paper, the effects of Ta substitution for Nb, on the microstructure and corrosion fatigue behavior of metastable Ti-18Nb-14Zr biomedical alloy are investigated for the first time. For this purpose, besides previously studied ternary Ti-18Zr-14Nb alloy, new quaternary Ti-18Zr-13Nb-1Ta (at.%) biomedical alloy was also synthesized by vacuum arc remelting method and subjected to thermomechanical treatment processes. The in situ electrochemical behavior and subsequent functional fatigue life of both alloys showed a strong dependence on the composition and microstructure. The electrochemical results from the test bench demonstrated that during monotonic cycling the fatigue life of Ta-added alloy was significantly longer than that of the Ti-18Zr-14Nb alloy. Thus, the addition of Ta to the ternary Ti-18Zr-14Nb alloy was found to be very effective in increasing the resistance to fatigue degradation mainly by exhibiting excellent protective passivation tendency. Based on the electrochemical evaluation and fractrographic characteristics, it is concluded that the combined effect of the stable passive film formation and higher development of a nanosubgrained structure in β phase results in the prolonged fatigue life of Ta-added alloy. •Ta addition favors the formation of nanosubgrained structure in Ti-Nb-Zr alloy.•Ta addition enables the formation of stable passive film on Ti-Zr-Nb alloy.•Ta addition increases the fatigue crack growth resistance of Ti-Zr-Nb alloy.•Ta addition is a promising way to increase the fatigue life of Ti-Nb-Zr alloy.