| Magnesium and its alloys are the lightest practical metal materials,the density of only 1.35 - 1.8 kg/m3,with high strength,stiffness ratio,electrical and thermal conductivity negative,good electromagnetic shielding,good shock elimination and cutting performance.In the aerospace,automotive, electronics,shipbuilding,construction,military and other fields,magnesium and its alloys have broad application.However,the Magnesium and its alloys have very negative electrode potential,and its surface oxide film is discrete, loose porous,which make it have a very low corrosion resistance in neutral, acidic and marine environment,except in the pH＞10.5(saturated Mg(OH)2 in pH value) solution.This thesis is aimed at AZ31 magnesium alloy through anodic oxidation and Micro-arc oxidation.Anodizing film and micro-arc oxidating film on AZ31 magnesium alloy were analyzied with tensile testing,SEM,EDX, XPS and XRD,and were gotten best formula.1.The effects of technological parameters on adhesive strength of anodic film on AZ31 magnesium alloy was studied through orthogonal experiments. Surface morphology,surface composition and surface element valence were studied by SEM,EDX,XPS,XRD.2.Thinner film,less treatment time,lower oxidation current formula were gotten through optimizing the fornula of largest tensile stress,also, adhesion property and surface potential were fixed,and it costs lower energy.3.The effects of technological parameters on adhesive strength of Micro-arc film on AZ31 magnesium alloy were studied through orthogonal experiments.Surface morphology,surface composition and surface element valence were studied by using SEM,EDS,XPS,XRD.4.The relationship of duty cycle and adhesion stress were got through duty cycle gradient test of Micro-arc oxidation.Matlab was used to dispose surface SEM photo by programming,the porosity was counted out,and the relationship of oxidating duty cycle,surface porosity and tensile stress were studied.
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