Study On Micro-arc Oxidation Process Of Titanium Alloy

In this paper,a two-step micro-arc oxidation experiment was earried out to prepare a high-performance film on Ti6A14V.Under the condition of certain electrical parameters and processing time,the influence of the input sequence of additives and the input amount on the performance of micro-arc oxidation ceramic film was investigated.The surface morphology,phase composition,film thickness,film hardness,wear resistance and corrosion resistance of ceramic film were determined by sem,X-ray diffractometer,thickness gauge,microhardness tester,MMW-IA universal friction testing machine and electrochemical analyzer,respectively.Based on the basic electrolytes of sodium hexametaphosphate,sodium silicate and sodium metaluminate,by comparing the experimental results of single additive and compound additive,it can be seen that the film with borax added first has the best comprehensive performance and the most dense and smooth surface.Rutile TiO2 accounts for a large proportion in the phase composition,and part of NaBH4 phase increases the corrosion resistance of the film.When chromium trioxide 1s added,the film has the strongest wear resistance,with a friction coefficient of around 0.5,a wear rate of 0.0035g,a wear rate of 0.0616%,and a corrosion potential of-0.44V.The film has a strong corrosion resistance.Change the addition ratio of borax,the film has good wear resistance,when the borax content is 1.9 g/L,the surface of the film morphology better under the condition of the film thickness increases,the phase composition of T1O2 rutile type diffraction peak stronger,membrane layer thickness(including m increase by 7.3 to 8.4(including m,increased from 785 HV to 820 HV hardness,wear resistance has been enhanced membrane layer,the friction coefficient decreased from 0.5 to 0.4,erosion rate dropped from 0.0035 g to 0.0025 g,the wear rate fell to 0.0426%from 0.0616%,improve corrosion resistance effect is not obvious.Borax content was deternined as 1.9 g/L,and then change the content of chromium trioxide,when chromiul trioxide content is 1.6 g/L,the surface of the film is more compact,reduce the roughness,the phase composition of TiO2 rutile type is not very obvious diffraction peak enhancement,membrane layer thickness(including m increase by 8.4 to 9.1(increased to 820 from 851 HV hardness,the wear resistance of film is continues to increase,the friction coefficient decreased from 0.4 to 0.3 or so,erosion rate dropped from 0.0025 g to 0.0015 g,the wear rate fell to 0.0255%from 0.0426%,The corrosion resistance effect was significantly improved,and the corrosion potential increased from-0.45V to-0.12V.