Electron microscopic study on interfacial characterization of electroless Ni-W-P plating on aluminium alloy

The interface between electroless plating Ni-W-P deposit and aluminium alloy (Al) matrix at different temperature heated for 1 h was studied using transmission electron microscope. The results show that the interface between as-deposited Ni-W-P deposit and Al matrix is clear. There are no crack and cavity. The bonding of Ni-W-P deposit and Al matrix is in good condition. The Ni-W-P plating is nanocrystalline phase (5-6 nm) in diameter. After being heated at 200 °C for 1 h, the interface of Ni-W-P deposit and Al matrix is clear, without the appearance of the diffusion layer. There exist a diffusion layer and educts of intermetallic compounds of nickle and aluminium such as Al3Ni, Al3Ni2, NiAl, Ni5Al3 and so on between Ni-W-P deposit and Al matrix after being heated at 400 °C for 1 h.