Study On Biological Friction Properties Of Ti6Al4V Surface Treated By Shotpeening And Implanted By Ni~+/N~+

In order to improve the tribological properties of Ti6Al4V surface,the surface was treated by shot peening and implanted by Ni⁺/N⁺.TTR18kW copper target,X ray diffraction,Nano Indenter II nano indentation,TR240 display surface roughness tester and Scanning electron microscope S-3000N were used to analyze XRD?mechanical properties?surface roughness and surface microstructure morphology.On this basis,the results as follows:1)The wear resistance of the surface modified layer of Ti6Al4V alloy is changed with the change of shot peening diameters.Shot peening diameter increases from 4mm to10mm,the surface roughness decreases from Ra1.32?m to Ra1.05?m,which have been greatly increased compared with the original sample.The nano hardness of the surface modified layerincreased and then decreased with the increase of the diameters,increased from 5.6GPa to 6.1GPa and then to 4.8GPa;the friction coefficientdecreased from 0.47 to 0.45 and thenincreased to 0.49.However,the overall performance of the modified layer after two shot peening is the worst.However,the mechanical performance of the modified layer is the worst after the shot peening treatment with diameter of 10mm and the diameter of 4mm.2)With the increase of Ni⁺/N⁺implantation parameters,Ti₂Ni,TiN phase increased,the values of diffraction peak increased and the wear resistance of substrate surface has been significantly improved.When Ni⁺injected energy increased from30KeV to 45KeV,the ion dose increased from 5×10¹⁶ions/cm² to 3×10¹⁷ions/cm²,the Ti₂Ni of the modified layer increased from 3.2%to 5.7%,the nano hardness increased from 4.8GPa to 7.5GPa,in different lubrication condition,the friction coefficient decreased;when N⁺implantation energy increased from 30KeV to 45Ke V,the ion dose increased from 1×10¹⁷ions/cm² to 3×10¹⁷ions/cm²,the nano hardness increased from 4.6GPa to 7.4GPa,in different lubrication condition,the friction coefficient decreased.However,the increase of injection energy is more beneficial to improve the tribological properties of the modified layer than that of the dose.3)Through the further studyof biotribological properties of Ti6Al4V shot peening and Ni⁺/N⁺implantation,the double modified layers,The results showed that the double modified layers significantly improved the wear resistance of Ti6Al4V alloy surface modified layer compared to single shot peening or single Ni⁺/N⁺implantation,thenano hardness of the surfacemodified layerand the wear microstructure of the surface modified layerare more reasonalcompared to shot peening or Ni⁺/N⁺implantation,while the contents of phase almost no change.