High‐cycle fatigue properties of beta Ti alloy 55Ti–30Nb–10Ta–5Zr, gum metal

Abstract

A B S T R A C T This paper describes the fatigue properties of the beta titanium alloy 55Ti-30Nb-10Ta-5Zr, generally referred to as 'Gum Metal'. Rotating bending fatigue tests have been performed in laboratory air and in a 3% NaCl aqueous solution. The results obtained were compared with those of a conventional beta titanium alloy, Ti-22V-4Al. In tensile tests, 55Ti-30Nb-10Ta-5Zr indicated elasticity and microplasticity in the elastic region. Thus, the elastic modulus slightly decreased with an increasing strain, and the work hardening was minimal during plastic deformation. The mechanical properties of both of the alloys were comparable. The fatigue strength of 55Ti-30Nb-10Ta-5Zr in laboratory air was higher than that of Ti-22V-4Al, which could be attributed to the higher fatigue crack initiation resistance of 55Ti-30Nb-10Ta-5Zr than Ti-22V-4Al, while the resistance to small fatigue crack growth was similar. The fatigue strength of 55Ti-30Nb-10Ta-5Zr in laboratory air and in the 3% NaCl aqueous solution was analogous. In addition, corrosion pits were not observed in the run-out specimen in the 3% NaCl aqueous solution, indicating a high resistance of 55Ti-30Nb-10Ta-5Zr against corrosion fatigue.

Fatigue strength of severely notched specimens made of Ti–6Al–4V under multiaxial loading

“…Some other contributions focused on the fatigue behaviour of titanium alloys have been published recently in this journal …”

Comprehensive review on alloy design, processing, and performance ofβTitanium alloys as biomedical materials

“…The effect of corrosive body environment on fatigue life of β Ti alloys has also been investigated [86,98,146,149,150,152]. A few reports suggested that high cycle fatigue strength of β Ti alloys is similar in air and in corrosive environments that simulate body conditions [146,149,152]. This is likely due to the high corrosion resistance of Ti alloys.…”

“…Nevertheless, fatigue strengths of several newly developed orthopedic β Ti alloys remain uncharacterised. Very limited comprehensive information is available on properties such as strain-controlled fatigue tests, crack growth of long cracks and small cracks, notch fatigue strengths, and fretting fatigue among others [98,152]. The effect of processing β Ti alloys by SPD and AM on fatigue response are wide open for research.…”

“…Homogenised:400 Wave like 375 (air/10 7 cycles) Ti-30Nb-10Ta-5Zr [152] β 558 689 20 58 300 (air/10 8 cycles) 320 (3% NaCl/10 7 cycles) Rotating bending fatigue Ti-35Nb (wt.%) [150] Water Rotating bending fatigue Ti-24Nb-4Zr-8Sn (wt.%) [148] β + α -1150 8 56 500 (air/10 7 cycles) Ti-29Nb-13Ta-4.6Zr (wt.%) [99] β + ω 900 1000 5 70 ∼600 (air/10 7 cycles) Ti-24Nb-4Zr-7.6Sn (wt.%) [86] α + β ∼1000 --∼75 425 (air/0.9% NaCl/10 7 cycles) Ti-29Nb-13Ta-4.6Zr (wt.%) [145] β 490 740 5 50 250 (air/10 7 cycles) Ti-29Nb-13Ta-4.6Zr [146] α + β >1000 >1000 ∼10 >80 780 (air/Ringers/10 7 cycles) a Fatigue strength is determined by axial fatigue tests unless otherwise noted. The solution temperature for corrosion-fatigue tests varied between room temperature and human body temperature.…”