第1个回答 2012-04-08
Using microarc oxidation electrostatic spraying composite process, in the AZ31magnesium alloy surface prepared to meet the appearance of magnesium alloy sample investigation, composite coating corrosion resistance and bonding properties. Using SEM observation of micro-arc oxidation ceramic layer and surface morphology of micro-arc oxidation electrostatic spraying composite coating microstructure; through the SEM with energy spectrum ( EDS ) analysis of the ceramic layer and the composite film surface element changes; using eddy current thickness measurement of micro-arc oxidation ceramic layer and electrostatic spraying layer thickness; by neutral salt spray test and electrochemical tests on micro-arc oxidation treatment and composite processing magnesium alloy specimen corrosion resistance; finally the Cross-cut test examines the binding force between the composite film.
The results show that: in different time and different duty ratio condition of micro arc oxidation of magnesium alloy, with epoxy resin as the electrostatic spraying preparation of magnesium alloy. According to the composite film, section surface micromorphology observation and elemental analysis, dusting can be immersed in the ceramic layer on the surface of the microporous, and fill up the holes, forming an effective sealing, and the excess powder in ceramic layer formed on the surface of uniform coating layer, reduces the surface roughness. Magnesium Alloy Microarc Oxidation electrostatic spraying composite coating than direct electrostatic coating binding force. Magnesium Alloy Microarc Oxidation electrostatic spraying composite coating corrosion potential and direct electrostatic spraying layer is lower than, AC impedance has significantly increased, salt spray test of composite coating on the weight loss is less and less, are examples of composite processing can greatly improve the corrosion resistance of magnesium alloy. Magnesium Alloy Microarc Oxidation electrostatic spraying composite coating corrosion resistance depends on the enhancement of powder filled microporous as well as in the ceramic layer formed on the surface of the barrier layer, which both slowing corrosion medium to the ceramic layer diffusion.