Effect of Substrate Surface Quality on Nickel Plating Property of ZK60 Magnesium Alloy

Abstract:

Nickel plating on the surface of magnesium alloy is widely used in the anti-corrosion of magnesium alloy workpiece, but blistering and peeling from nickel plating will seriously affect service life of the workpiece. In this paper, effects of the different substrate surfaces on nickel plating properties of ZK60 magnesium alloy were studied. The results showed that the surface scratch and corrosive pitting significantly reduced the coating quality and caused blistering and peeling from nickel plating. The surface scratch of the substrate was retained under the nickel plating layer, which made the coating thinner, and caused stress concentration in the coating, and increased the probability of coating cracking. Differences in electrochemical properties between impurities in pitting pits and magnesium substrate led to thinning of the coating and weakened the adhesion of the coating. Therefore, good substrate surface finish and no substrate surface corrosive pitting are the guarantee of high quality nickel plating of magnesium alloy workpiece.