Fatigue performance evaluation of a Nickel-free titanium-based alloy for biomedical application - Effect of thermomechanical treatments

Geneviève Mussot-Hoinard (1) , Wafa Elmay (1) , Laurent Peltier (1, 2) , Pascal Laheurte (1)

1 LEM3 - Laboratoire d'Etude des Microstructures et de Mécanique des Matériaux
2 ENSAM - METZ - Ecole Nationale Supérieure d'Arts et Métiers - Centre de Metz

In the present work, structural fatigue experiments were performed on a Ti-26Nb alloy subjected to different thermomechanical treatments: a severe cold rolling, a solution treatment and two aging treatments at low-temperature conducted after cold rolling in order to optimize the kinetics of precipitation. The aim is to investigate the effect of microstructural refinement obtained by these processes on fatigue performances. Preliminary tensile tests were performed on each state and analyzed in terms of the microstructure documented by using X-Ray diffraction and TEM analysis. These tests clearly promote the short-time-aged cold-rolled state with a fine α and ω phases precipitation. An interesting balance between mechanical properties such as high strength and low Young's modulus has been obtained. Cyclic bending tests were carried out in air at 0.5%, 1%, 2% and 3% imposed strain amplitudes. At low straining amplitude, where the fatigue performances are at their best, the cold-rolled state does not break at 3×10E6 cycles and the long-time aged precipitation hardened state seems to be a good competitor compared to the cold-rolled state. All failure characteristics are documented by Scanning Electron Microscopy (SEM) micrographs and analyzed in term of microstructure.

Mots clés: Scanning Electron Microscopy; X-Ray diffraction; Fatigue; Titanium alloy; Thermomechanical treatments

Domaines: Mécanique des matériaux [physics.class-ph]; Biomatériaux

Geneviève Mussot-Hoinard, Wafa Elmay, Laurent Peltier, Pascal Laheurte. Fatigue performance evaluation of a Nickel-free titanium-based alloy for biomedical application - Effect of thermomechanical treatments. Journal of the mechanical behavior of biomedical materials, 2017, 71, pp.32-42. ⟨10.1016/j.jmbbm.2017.02.024⟩. ⟨hal-01558144⟩