ABSTRACT
In this study, the microstructure and mechanical property of Al/Cu clad material fabricated by differential speed rolling at room temperature were evaluated. Al and Cu plates were prepared and mechanically cladded at a differential speed ratio of 2:1 between the upper and lower rolls. Post- heat-treatment was carried out after the mechanical cladding at 400 °C for 60 min to induce the formation of intermetallic compound layers at the bonded interface of Al/Cu. As a result, differential speed rolling afforded a soundly cladded interface without any defects such as voids and cracks. In addition, intermetallic compound layers such as Al4Cu9 and Al2Cu were formed at the mechanically bonded interface during post-heat-treatment for 60 min, which led to an increase in Vickers microhardness value more than 30% relative to the base material. Therefore, we systematically explained the relationship between formation of intermetallic compounds and mechanical property of Al/Cu clad materials in this study.
ABSTRACT
This study was carried out to evaluate the development of microstructures and mechanical properties on friction welded dissimilar materials with a light weight. For this work, Al6063 and Duralumin alloys with a shape of rod were selected as experimental materials, and friction welding was performed under conditions with a rotation speed of 2,000 RPM, a friction load of 12 kgf/cm2 and an upset force of 25 kgf/cm2, respectively. After welding, the microstructural analysis such as the grain boundary characteristic distributions and the formation of intermetallic compounds was analyzed by electron back-scattering diffraction method and transmission electron microscopy, respectively. In addition, the evaluation of mechanical properties on welded materials was conducted by Vickers microhardness and tensile test. As a result, applying the friction welding led to the significant grain refinement from 50 µm in base material to 2 µm in welded zone, respectively. In case of mechanical properties, Vickers micro-hardness and tensile strength of the welded material occupied 81% and 96% in fraction relative to the base material, respectively, which was attributable to the formation and growth of intermetallic compounds during the welding.
