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 8C 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 8C for 1 h.