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Magnesium is the sixth most abundant metal in the Earth's surface , magnesium alloy has a high thermal conductivity, anti- magnetic interference , die casting thin-walled parts and easy to recycle , etc. Following the steel, aluminum , magnesium alloy is becoming the third largest metal works material , known as the \However, due to the poor corrosion resistance of magnesium and magnesium alloy , showing a high chemical and electrochemical activity , the application of magnesium alloy is extremely limited . The electroless plating can be significantly improved magnesium alloy surface corrosion resistance , but Since magnesium is a hard plating base body , the effect of its pre-processing will directly affect the chemical plating corrosion resistance. In addition , the bath scientific preparation to get the best effect of the coating . This thesis the following: ( 1 ) to study the effect of chemical plating , chemical plating pretreatment found that the grinding of the sample to achieve a certain degree , not too rough , the roughness can effectively reduce the porosity 0.6 . Alkaline cleaning degreasing process take quadrature formula ( contain NaOH and Na3PO4 well as of Na2CO3 ) explore the caustic washing process factors . Pickling and activation of the pretreatment has a corresponding influence factor, the orthogonal test for these factors has been set to the conditions in the chemical bath . Through research on several factors , and electroless plating the relationship between the detection criteria , found that the best pre-treatment formulations . (2 ) by orthogonal experiment to study the influence of chemical plating bath composition and objective conditions such as temperature , pH value , the time on the stability of the bath , the coating of corrosion resistance and coating hardness . Polarization curve , reflecting coating by electrochemical workstation corrosion in 3.5% NaCl solution . Detecting the porosity of the coating , the magnesium reagent by EDS , energy dispersive analysis of the various components after plating by orthogonal test analysis , the most important is the best bath formulations , and its coated phosphorus content in the range of 9% to 11 % diffraction pattern between the X - ray diffraction analysis curve was \(3) on the basis of existing bath by adding varying amounts of the complexing agent and found that the thickness of the Ni-P plating , and will not change with infinitely improved by adding complexing agent composite . Without complex agent chemical coating for comparison and found that the corrosion resistance and hardness are improved .
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