Research On Abrasion Resistance Of Titanium Alloy Ti13Nb13Zr By Laser Shock Texturing

Titanium alloy Ti13Nb13 Zr,which has good corrosion resistance,biocompatibility and low elastic modulus,is the preferred material for human bone replacement.However,the wear resistance of titanium alloy is poor,which seriously restricts the application of titanium alloy.In order to improve the wear resistance of titanium alloy,the wear resistance of medical titanium alloy Ti13Nb13 Zr was studied by laser shock texturing.The main research works are as follows:(1)The influence of processing parameters on the deformation and mechanical properties of titanium alloy Ti13Nb13 Zr was studied based on single point laser micro shock experiment.Results show that with the increase of laser energy and impact times,the depth of the pit,nano-hardness and elastic modulus and the effect of microstructure depth increases gradually,but the growth rate decreases.At the center of the pit,the grain size of the surface titanium alloy is the smallest,with the depth increasing,the grain refinement degree decreases gradually.(2)The numerical model of the laser impact titanium alloy Ti13Nb13 Zr was established,and the accuracy of the numerical model was verified by the experimental data.The effects of laser energy,pit spacing and pit dislocation on the surface morphology and residual stress were studied by multi-point laser shock simulation,providing support for anti-friction and anti-wear mechanism.(3)In order to obtain the influence of process parameters on friction coefficient and mass,and the optimum process parameters,the friction coefficient and mass of the Box-benhken experimental design response value were fitted and analyzed.The results of surface micro texturing with a diameter of 0.8 mm shows that the friction coefficient and mass increase with the increasement of laser energy;Dimple dislocation increases from 0 mm to 0.4 mm,friction coefficient and mass decreases gradually;With the increase of the dimple distance,the mass and friction coefficient decreases first and then increases slowly,and the friction coefficient and the wear are the smallest at the distance of 1.5 mm;Based on the optimized analysis of the friction and mass,it found that minimum value of the friction coefficient and mass process parameters of laser energy,distance and dislocation are[1.2 J,1.5 mm,0.4 mm] and [1.2 J,1.49 mm,0.4 mm].Surface micro texturing with a diameter of 0.8 mm shows that the friction coefficient and wear decrease with the increasement of laser energy,and dislocation;Friction coefficient and wear decrease and then increase with the increasement of dimple distance;Based on the analysis of the response value,the optimal process parameters of friction coefficient and wear are the same(1.57 J,1.27 mm,0.37 mm)。(4)By changing the speed,load and time,the influence of working conditions on the surface friction performance was investigated.The results shows that the friction coefficient,mass,depth of wear scar and width of wear scar decrease with the increasement of rotational speed,but increase with the increasement of load.The results of untreated surface scar SEM analysis shows that the untreated surface wear behavior is abrasive wear,adhesive wear,matrix accumulation and contacting fatigue damage.The spot diameter of 0.8 mm surface micro texture wear behavior mainly for slight abrasive wear,and the spot diameter of 0.5 mm surface micro texture wear behavior mainly for adhesive wear.To sum up,laser shock texturing can effectively improve the wear resistance of Ti13Nb13 Zr.