N. Dhawan, M. Wadhwa, Punjab Engineering College, Chandigarh, India
Magnesium (Mg) and its alloys are being used as structural components in industry because of their high strength-to-weight ratio and relatively high stiffness. A shortcoming of Mg based alloys is their high electrochemical activity and poor corrosion resistance. Therefore, coatings or surface treatment are needed for protection purpose. Electroless nickel-plating on magnesium alloys is one of proper protection method because the deposited nickel is very resistant to corrosion and abrasion.
This paper reports work on Electroless plating of Ni on Mg alloys. Mg alloys were used as the substrates to investigate the deposition rate, nucleation process, and microstructure of the Electroless Ni coatings. It was found that deposition processes are strongly affected by the alloy substrates. Ni plating on AZ31 alloy has higher deposition rates and lower surface roughness than that of other substrates. SEM investigations showed that nodular morphology of Ni coatings formed on the substrates.
Application of electrochemical plating on Mg and its alloys requires surface pretreatment to ensure adhesion and integrity of the coatings. These steps include cleaning, etching and fluoride activation. Deposition was initiated on the phase and grain boundaries due to the inter-grain galvanic coupling. Future work is on the lines how to improve corrosion resistance of Magnesium alloys by conversion treatment.
Magnesium and its alloys are being used as structural components in industry because of their high strength-to-weight ratio and relatively high stiffness but their shortcoming is their high electrochemical activity and poor corrosion resistance. Electroless nickel-plating on magnesium alloys is one of proper protection method because the deposited nickel is very resistant to corrosion and abrasion.
This paper reports work on Electroless plating of Ni on Mg alloys that were used as the substrates to investigate the deposition rate, nucleation process, and microstructure. Ni plating on AZ31 alloy has higher deposition rates and lower surface roughness than that of other substrates. SEM investigations showed that nodular morphology of Ni coatings formed on the substrates.
Application of electrochemical plating on Mg requires surface pretreatment to ensure adhesion and integrity of the coatings. Deposition was initiated on the phase and grain boundaries due to the inter-grain galvanic coupling.
