Effect of Ni-based conversion coating and Ni-P electroless plating on the bonding process of pure Al and AZ31 alloy

For the first time, the present study investigates the preparation of Al/Mg bimetal using Ni-based conversion plating and Ni-P electroless plating by means of diffusion bonding. In this study, AZ31 alloy was coated with an Ni-based interlayer by conversion plating and an Ni-P interlayer by electroless plating; the Al/Mg bimetallic materials were prepared by diffusion bonding in an air atmosphere. For conversion plating, the thickness of the Ni-based layer is several hundred nanometers. When heat-treated at 450 C for 90 min, most of the interfaces between Al and AZ31 alloy bond together well. For electroless plating, the thickness of the Ni-P layer is about 10 mu m for a plating time of 60 min. When heat-treated at 450 degrees C for 150 min, good bonding between pure Al and AZ31 can be obtained.