Surface treatment and nickel plating of iron powder metallurgy parts for corrosion protection

The aim of this study is the evaluation of corrosion behavior of nickel coated iron compacts produced by powder metallurgy (PM). To improve the quality of PM products three different secondary operations: copper infiltration, resin impregnation and steam-treatment were applied for pore closuring of iron PM specimens before being electroplated by nickel. After microstructural studies, salt fog exposure and electrochemical tests were carried out to study the corrosion behavior of the nickel coated specimens. The results showed that, nickel coated steam treated specimens exhibit better performance on corrosion testing in comparison with others. Although copper infiltrated specimens showed less porosity in PM products, observed limited corrosion behavior can be due to its galvanic effect.