Research On The Influence Of Electroplating Process On Corrosion Resistance Performance Of Automobile Plastic

Plastic plating is a common surface treatment process to plate a thin layer of other metal or alloy on the surface of some metal or nonmetal,which can prevent corrosion,improve wear resistance and electrical conductivity,and enhance beauty of material.To some extent,plastic electroplating products can be used as alternative of metal products.As for plastic electroplating,especially automotive exteriors plastic electroplating parts,it has very stringent requirements to ensure the corrosion resistance and impact resistance in addition to the need to ensure the fine appearance.In recent years,the automobile sales have increased year by year,and the after-sale claims caused by the corrosion of plastic electroplating parts are also increasing.The owners pay attention to the appearance quality of the automobile,and make the production enterprise strengthen the consciousness of the quality.How to ensure the corrosion resistance of products to meet the needs of consumers,this is the focus and direction of this study.In this paper,the influence of coating thickness on the surface corrosion resistance performance of plastic electroplating parts with Cu+Ni+Cr plating system is studied.Three samples under different coating thickness were prepared according to the standard of Volkswagen of Germany,Toyota of Japan,and China Faw,respectively.The surface corrosion resistance performance was tested through CASS experiment,climate alternating + salt fog resistance experiment.According to the experimental results,it can be seen that corrosion resistance strength of the sample with a semi bright nickel layer thickness of 15 microns and bright nickel layer thickness of 10 microns,is 1.5 times over that of the sample with a semi bright nickel layer thickness of 8 microns and bright nickel layer thickness of 8 microns.All three coating requirements can meet the demands of the CASS experiment 48 hours and the climate change of 96 hours + salt fog test for 240 hours.But in coastal areas,the high salinity contained in the air can have a huge impact on the corrosion resistance performance of the electroplating surface.Therefore,the production enterprises with high market share in the coastal areas should increase the thickness of the coating.At the same time,the influence of the size of the potential difference against corrosion has also been researched.It is proved that the corrosion resistant ability of plastic plating parts increases with the addition of potential difference between semi bright nickel and bright nickel,microporous nickel and bright nickel.But there are some manufacturers have no specifications and requirements on this technology.The quality standards of automobile manufacturers need to be improved.