Study On Surface Strengthening And Tribocorrosion Behavior Of Biomedical Pure Titanium

Titanium alloy has excellent properties,so it has a wide range of application prospects in biological medicine,aerospace and other fields.However,the low surface hardness and poor wear resistance of titanium alloy will cause premature failure,which greatly limits its scope.So,this paper used induction heating technology to nitrided treatment on medical TA1 titanium alloy and an effective nitrided layer was obtained,then the nitriding layer produced was characterized by XRD,SEM-EDS,XPS and EBSD.Meanwhile,the micro-scale mechanical and tribocorrosion properties of the nitrided layer were studied,and the formation of the induction nitrided layer and the wear-corrosion damage mechanism were discussed.The induction nitrided layer can be prepared on the surface of titanium alloy about 20?m by induction nitrided treatment for 60 min.The nitrided layer is composed of Ti N,Ti₂N and Ti N_0.3 phase(the diffusion layer).With the increase of the induction nitrided time,the thickness of the nitriding layer and the surface roughness increase.The surface hardness of the induction nitrided layer can reach up to 1171.86 HV_0.25,and the stiffness and elastic modulus also increase.The scratch test shows that there is no fracture or delamination on the surface of the induction nitrided sample.After nitriding,the elastic strain failure(H/E)and yield pressure(H³/E²)on the surface of titanium alloy increase,indicating that the formation of nitriding layer can effectively improve the wear resistance and plastic deformation resistance of titanium alloy.The tribocorrosion performance of the induction nitrided layer was tested in simulated body fluids under different loads.The results show that the inductive nitrided layer can effectively prevent the loss of electrons in titanium alloy,and the corrosion resistance of titanium alloy was improved.With the increase of the load,the surface damage of the nitride layer is aggravated,and the wear mechanism is mainly abrasive wear.In the synergistic effect of wear and corrosion,the corrosion weight loss caused by wear?Mwc is dominant.Through the induction of the nitrided layer microstructure and performance analysis show that a nitride layer with excellent performance can be prepared on titanium alloy surface by induction nitrided technology,and it effectively improve the comprehensive performance of titanium alloy.The paper has accumulated a lot of experimental data for the surface strengthening and toughening of titanium,and provides a theoretical reference for the expansion of the application range of titanium alloy.