EXPERIMENTAL INVESTIGATIONS ON THE INFLUENCE OF THE THERMAL CONDITIONS DURING COMPOSITE CASTING ON THE MICROSTRUCTURE OF Cu-Al BILAYER COMPOUNDS

Metallic material compounds are of technical interest as they allow the combining of specific properties of different materials into one component. In particular, compounds of copper (Cu) and aluminum (Al) are a current object of research. There are different fabrication processes, such as roll cladding or overlay welding. In recent years, a variety of alternative bonding methods were investigated, among other composite casting processes. A notable problem of Cu-Al composites is the formation of hard and brittle interface layers which reduce the mechanical properties of the compounds. Therefore, the reduction of these layers is one of the objectives of the development of new fabrication processes to realize suitable industrial applications. In this study, gravity casting experiments are carried out to produce Cu-Al bilayer composites and to determine the influence of the thermal process parameters on their properties. Two experimental setups using sand molds are developed, and casting experiments with varying thermal parameters are carried out. Specimens of the cast composites are extracted, metallographic examined and the hardness profile is determined. Hence, it is possible to identify the influence of thermal parameters on microstructure and hardness of cast Cu-Al bilayer composites.