| Magnesium alloys have excellent properties such as low density,high specific strength and good specific rigidity,and are rich in reserves,which have broad application prospects.However,due to the extremely high chemical reaction activity of magnesium alloys,they are easily corroded,which limits the application of magnesium alloys..Magnesium alloy micro-arc oxidation treatment can greatly improve the corrosion resistance of magnesium alloys.However,because the surface of the micro-arc oxidation film is loose and porous,the micro-arc oxidation film is sealed again to further improve the corrosion resistance of the magnesium alloy.It has far-reaching practical significance.In this paper,through two treatment processes of micro-arc oxidation-electrophoresis composite treatment and micro-arc oxidation-UV curing composite treatment on magnesium alloys,composite films with different characteristics are prepared respectively,and the electrophoresis process parameters and UV curing process parameters are studied by controlled variable experiments.The effect of the composite membrane layer on the performance of the composite membrane layer and the corrosion resistance of the membrane substrate prepared by the two processes were investigated,and the optimal process parameters were obtained through performance testing.Research indicates:(1)During the preparation process of magnesium alloy micro-arc oxidation-electrophoresis composite film layer,there is less environmental pollution and simple operation.The porosity of the micro-arc oxidation layer provides good basic conditions for electrophoresis.The neutral salt spray test can reach more than 200h,and the acid resistance test can reach more than 20h.The corrosion resistance is very excellent,which has great application significance for the surface treatment of ship hulls,spacecraft and other equipment.(2)The preparation process of the magnesium alloy micro-arc oxidation-UV curing composite film is environmentally friendly and pollution-free,the curing rate is fast,and the cost is low.The paint solution can be adjusted in color,which can improve the decoration of the film.The dipping method during curing is more effective than spraying The film is more uniform.It cannot be directly cured into a film on the surface of the magnesium alloy.It needs to be cured after micro-arc oxidation.In actual application,only one layer needs to be cured.The corrosion resistance can exceed 200h in the neutral salt spray test,which is good for the surface of 3C equipment.Processing has great application significance.(3)The thickness of the oxide layer has a certain effect on the thickness,surface roughness,bonding force and corrosion resistance of the composite film.For magnesium alloy micro-arc oxidation-electrophoresis composite film,the thicker the oxide layer,the thicker the composite film layer,and the lower the surface roughness.When the oxide layer thickness is 25 ? m,the bonding force and corrosion resistance are the best;For alloy micro-arc oxidation-UV curing composite film,the thicker the oxide layer,the thinner the composite film,and the greater the surface roughness.When the thickness of the oxide layer is 15 ? m,the bonding force and corrosion resistance are the best.(4)The electrophoresis/curing time has a certain effect on the thickness,surface roughness,bonding force and corrosion resistance of the composite film.For magnesium alloy micro-arc oxidation-electrophoresis composite film,the longer the electrophoresis time,the thicker the composite film.When the curing time is 120s,the surface roughness is the lowest,the bonding force and the corrosion resistance are the best;For the arc oxidation-UV curing composite film,the longer the curing time,the overall thickness of the composite film does not change much.The surface roughness is the lowest when the curing time is 40s,and the bonding force is the best when the curing time is 60s.The curing time is At 20s and 60s,the corrosion resistance is the best. |
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