The technology for direct electroless nickel plating on AZ91D Mg alloy was studied. The surface morphologies of Mg alloy after pre-treatment electroless nickel plating and direct electroless nickel plating were analyzed,and the effect of electroless plating conditions on the morphology of the Ni-P coating was explored. The adhesion of the coating to Mg alloy substrate and the microstructure of the coating were measured. Results show that smooth and compact amorphous Ni-P alloy coating with high hardness and...