Study On The Anodizing Characteristics And Influencing Factors Of Titanium In Sulfuric Acid System

In order to satisfy the titanium and titanium alloys in the aerospace,shipbuilding,widely used in the field of biomedica and life,and reduce the loss as a result of corrosion,to improve the corrosion resistance of titanium and titanium alloy and improve the surface performance,achieve the goal of high efficiency production,boast skillful use,based on the industrial pure titanium TA2 as experimental samples,in 0.5 mol/L sulfuric acid as electrolyte,anodize oxidation process of surface modification of method,studied the anodize oxidation process and the influencing parameters,And through a lot of experiments to determine the technological parameters of voltage,time and temperature on the surface oxide film layer macroscopic characteristics,characteristics of micro structure and corrosion resistance.Second,in an anodic oxidation on the basis of the sample,again high voltage applied to the second anodic oxidation,and studied by the micro structure of samples after the secondary anodic oxidation characteristics,chemical composition and corrosion resistance.Anodic oxidation process of the experimental results show that the optimization of process parameters and control conditions of TA2 anodized layer can take on the color of the rainbow,and even color,bright.Membrane layer organization has good stability,compact structure,and corrosion resistance was significantly enhanced,anodic oxidation to a certain extent,has realized the material the unification of the functionality and aesthetics.In addition,the process is simple and highly effect,can satisfy the metal surface anodic oxidation modification and engineering practical application requirements.Anodic oxidation process conditions(voltage,time,temperature)on the co louring film plays a very important role,the performance of the voltage is one of the most important influencing factors.With the change of the voltage,change the thickness of the oxide film layer,layer caused by interference effect color assumes the regularity of the change.At the appropriate time and temperature,the increase of voltage on the surface of the oil film is more dense,smooth,and uniform coverage on the substrate,play a very good protection effect on metal substrates,corrosive medium because due to the effect of barrier of the membrane layer of metal corrosion.Under the same voltage and temperature,the change of time,the rate of film color change is not big,but when the time more than 30min,the film will appear the phenomenon of "pink",results in uneven coating color.When the time for more than 10min,membrane layer of density and corrosion resistance over time will be reduced.When the temperature more than 400C,film began to appear "pink"phenomenon,as temperatures continue to rise,microporous membrane layer surface populations and corrosion resistant performance degradation.When the temperature below 20 ?,due to the lower temperature will influence the diffusion rate of atoms and ions,cause the anodic oxidation process is slow,low efficiency.Can,therefore,it is concluded that the best time for 5min to 10min,the best temperature is 20 ? to 30?,and the voltage can undertake choosing according to specific needs.For constant voltage mode of industrial pure titanium TA2 secondary anodic oxidation,respectively by scanning electron microscope(SEM),X-ray photoelectron spectroscopy(XPS)and electrochemical workstation membrane layer surface color,appearance characteristics,composition and potentiodynamic polarization curves.The research results show that the secondary anodic oxidation prompted membrane layer in anodic oxidation on the basis of growth,again lead to membrane layer thickness increases,the coating color deepened.TA2 pure titanium after anodic oxidation layer of oxide film are porous morphology,the formation of secondary after anodic oxidation film layer,more dense smooth surface morphology,microporous further decline;Gained by the secondary anodic oxidation film layer is an anodic oxidation has more stability of TiO2 rutile type,film surface activity is reduced,the corrosion current density decreased,corrosion resistance improved.