Composite Treatment Of Micro-arc Oxidation And High Current Pulsed Electron Beam On Titanium Alloy

In this paper,a new hard metal ceramic composite modification layer was prepared on the surface of TC4 alloy by Micro-arc oxidation(MAO)and High Current Pulsed Electron Beam(HCPEB).Under the same rest condition,the composite modified cermet layers were prepared by different micro-arc oxidation electrolyte formulations,or under different micro-arc oxidation forward voltages,or at different oxidation times.According to test results,the studies determined the causes which affect precast micro-arc oxidation process parameters have a composite layer modified layer.Selected the prefabricated layer process parameters.The properties of hardness,wear resistance and corrosion resistance of the micro-arc oxidation layer,the pulsed electron beam modified layer and the composite composite coating were tested respectively.Comparative analysis the effects of different modification methods on the properties of the coatings.Discuss the formation of reasons.By observing the composite modification layer formation process,analyzed and summarized the changes in law of surface morphology,organizational structure and performance of modified layer.Combined with the influence of parameters and the properties of the Composite treatment layer,preliminary elaborated the formation mechanism of Micro-arc Oxidized and High Current Pulsed Electron Beam Composite treatment layer on Titanium alloy.The results showing that the composite coating with smooth and bright composite surface can be obtained by high current pulsed electron beam treatment with different micro-arc oxidation electrolyte formulations.In comparison,the surface quality of the Composite treatment layer is higher with the Na2SiO3-(NaPO3)6-NaAlO2 micro-arc oxidation electrolyte formulation.Both the forward voltage and the oxidation time of MAO were the influencing factors of the composite modification layer.The forward voltage is the main factor influencing the microstructure of the composite coating.The optimum process parameter of the forward voltage is 500 V.Oxidation time is the main influencing factor of surface quality of composite layer,and the optimum process parameter of oxidation time is 5min.From the performance point of view,the Composite treatment layer from all aspects of a single modified layer has a better performance.The Composite treatment layer not only contains micro-arc oxidation of hard oxide ceramic phase as the enhanced phase,while the remelting effects of pulse electron beam can reduce the surface defects.The hardness of the modified layer is about 4 times that of the base and 2 times of that of the microcar oxidation layer.The abrasion resistance of the composite layer is also improved.The wear resistance coefficient is only 0.19 and the wear amount is 0.0009 g.In the meanwhile,the corrosion resistance of acid-base salt of the Composite treatment layer is improved to some extent.From the mechanism of formation,the surface volcanic hill disappeared,and the microstructure of the modified layer became smooth.The high temperature stable phase of the modified layer increased.Experiments show that,the surface of the composite layer has a texture-like structure and melting pit and other defects,in which melting pit can be eliminated,texture-like tissue can not disappear.