RESUMO
Objective To study the corrosion-fatigue properties of a novel low modulus Ti-3Zr-2Sn-3Mo-25Nb(TLM)titanium alloy subjected to simulated body fluid(SBF).Methods Ti-6Al-4V(TC4)alloy was used as the control group.The electrochemical corrosion polarization curves of the two titanium alloys were measured in SBF.The pre-corroded TC4 and TLM titanium alloy samples were subjected to rotational bending fatigue tests.The loading stress amplitude and fatigue fracture cycle relationship was established using the experimental data,and the stress life curves were drawn.Subsequently,the fracture mechanism was analyzed by analyzing the corrosion fatigue micro-fracture morphology of the sample,and fatigue analysis on the titanium alloy sample was then conducted combined with the finite element software.Results The self-corrosion potential of the TC4 titanium alloy under stress annealing was lower than that of the TLM titanium alloy after heat treatment.The TLM titanium alloy was most sensitive to changes in cyclic stress.A comparison between the simulation and experimental results showed that the TC4 titanium alloy under stress annealing had a higher fatigue strength and stronger resistance to crack propagation than the TLM titanium alloy did after heat treatment,whereas its corrosion resistance was the opposite.Compared to the specimens without pre-corrosion treatment,the brittleness of the TLM titanium alloy increased,and its fatigue performance decreased after pre-immersion in SBF.Conclusions Through comparative analysis,the reliability of the test results proved to be high,and the COMSOL finite element software could effectively predict the fatigue life of titanium alloy materials.