Study On Friction And Wear Resistance Of Anodized Film Layer Of TC4 Titanium Alloy By Process Parameters

Titanium alloys have good physical and mechanical properties and are widely used in various fields.However,titanium alloys also have defects of low hardness and poor wear resistance,which reduce their service life.In order to improve the hardness and wear resistance of titanium alloy,anodizing technology was used to prepare the oxide film on the surface of titanium alloy by changing electrolyte system,concentration and anodizing process parameters.The microhardness and roughness of the film were systematically studied.the parameters such as friction coefficient and wear amount of the film were obtained by friction and wear tests,and the morphology after wear was observed and analyzed to establish the relationship between the anodizing process and friction performance of titanium alloy.The microstructure and hardness of the anodized film layer under different systems were analyzed.It was found that the surface of the oxide film obtained in the acidic electrolyte was uniform,the crystallinity was high,the hardness was the highest,and the surface roughness was the lowest.Subsequently,the effects of different phosphoric acid concentration,sodium fluoride concentration and citric acid concentration on the properties of the oxide film in the acidic electrolyte were studied.Taking the oxygen concentration,microhardness and roughness of the film as indicators,and the optimal concentration of the three was 75 mL/L.1g/L,20 g/L,respectively.The effect of process parameters on the anodized film was studied.It was found that the microhardness of the film increased first and then decreased and the roughness of the film first decreased and then increased with the increase of oxidation voltage,the microhardness and roughness were optimal at 90 V.the hardness of the film increased and the roughness of the film decreased with the increase of oxidation time before the oxidation time was 60 min,the film layer changed little when the oxidation time exceeded 60 min.The microhardness of the oxide film layer decreases as the oxidation temperature increases,and the roughness increases as the oxidation temperature increases.The relationship between the microhardness and roughness of the anodized film layer is determined by orthogonal test: oxidation voltage>oxidation temperature>oxidation time.The optimum anodization process parameters were obtained in an acid system dominated by phosphoric acid: the voltage is 90 V,the time is60 min,the temperature is 5?.The friction and wear properties of the anodized film layer under different process parameters were studied.It is concluded that the friction coefficient of the film increases first and then stabilizes with the increase of oxidation voltage,the friction coefficient and wear amount were the smallest at 90 V,the surface has uniform shallow furrow after the wear.The friction coefficient and the wear amount decrease with the increase of oxidation time,the surface wear marks are the shallowest and no film peeling occurs when the oxidation time is60 min.The friction coefficient and the wear amount increase with the increase of oxidation temperature.the friction coefficient is stable and the fluctuation is small when the oxidation temperature is 5 ?,the scratch surface of the sample is the shallowest and there are a few furrows.The oxide film layer prepared under the optimized process parameters has a better Low friction coefficient and wear amount,there are few furrows on the surface after friction,and the number of abrasive grains attached to the furrow is also small.