Cyanide-free pre-treating solution for electroplating copper coating layer on magnesium alloy surface and a pre-treating method thereof

摘要

A pre-treating solution for electroplating magnesium alloy surface contains copper ions, a complexing agent and an additive, wherein the complexing agent is selected from potassium sodium tartrate, potassium tartrate, sodium tartrate, tartaric acid, and dissolvable salts derivative from tartaric acid and the additive is selected from sodium phosphate, sodium hypophosphite, phosphoric acid and dissolvable salts derivative from phosphoric acid or hypophosphite acid. The magnesium alloy is dipped in the pre-treating solution and electroplated with a copper coating layer. Then, the magnesium alloy is further dipped in a copper sulfate solution for thickening the copper coating layer and lastly coated with an anti-corrosion metal layer. Thereby, magnesium alloy has excellent anti-corrosion and anti-wearing efficiency and varnish appearance. Moreover, the pre-treating solution contains no cyanide and thus is low toxic and safe to operator during electroplating and to environment after discharging.