A study on the development of large aluminum flange using the casting/forging process

Abstract

In this study, the casting/forging process has been applied in manufacturing a large aluminum flange, in order to reduce press capacity and material costs. Firstly, a hot compression test was performed with cast cylindrical billets in order to determine the optimum forging conditions for the aluminum flange. The optimum range of forging temperature of Al 5083 was from 420 to 450 °C. The suitable strain rate was 1.5/s. In order to find the change in mechanical properties depending on the effective strain of the cast aluminum billets, a hot upsetting test was performed with rectangular blocks and then a uniaxial tensile test was performed with specimens cut from the upsetted billets. The tensile strength and the elongation of cast/upsetted aluminum billets were increased significantly until the effective strain was 0.7. And FE analysis was performed to determine the configurations of the cast preform and die for an aluminum flange. In the FE analysis, the forging load-limit was fixed at 1500 t for low-equipment cost. The cast preform was designed so that the effective stain around the neck of the flange exceeded 0.7. From the result of FE analysis, optimal configurations of the cast preform and the die were designed for a large flange. The filling and solidification analysis for a sound cast preform was carried out with MAGMA soft. In the forging experiment for an aluminum flange, it was confirmed that the optimal configuration of the cast preform predicted by FE analysis was very useful. The cast/forged products using designed preform were made perfectly without any defects.