Developing Empirical Relationships to Predict Diffusion Layer Thickness, Hardness and Strength of Al-Cu Dissimilar Joints

The principal difficulty when joining Aluminium (Al) and commercial grade Copper (Cu) lies in the existence of formation of oxide films and brittle intermetallics in the bond region. However, diffusion bonding can be used to join these alloys without much difficulty. Temperature, pressure and holding time are the three main variables, which govern the integrity of the diffusion bonds. The experiments were conducted based on three factors, five-levels, and central composite rotatable design with full replications technique. Empirical relationships were developed to predict diffusion layer thickness, hardness, strength of Al-Cu joints incorporating process parameters using Response Surface Methodology. The developed relationships can be effectively used to predict the bond properties at 95 % confidence level.