Effect of reduction ratio in flow forming process on microstructure and mechanical properties of a 6082 Al alloy

Flow forming is a cold deformation process in which hollow cylindrical or conical parts with different geometric configurations are produced using tools such as balls, rollers, or flow forming wheels on specialized mandrels. Because it enables the production of parts without any further modifications or with minimal modifications before their use in service, the process is categorized as an NSF technology (net-shape forming), and therefore the flow formed parts can be considered as a final product. The aim of this study is to investigate the microstructure and mechanical properties of a flow formed 6082 Al alloy, which was initially in W-temper condition. Hollow cylindrical preforms were first manufactured by machining, and subsequently solution heat treated and quenched. Then, the parts were flow formed with 3 different reduction ratios (45%, 55% and 65%) prior to aging at 177 °C for 8 h to achieve T8 temper condition. Microstructures of the flow formed parts were examined by an optical microscope, and hardness and tensile tests were conducted. The results revealed that increasing reduction ratio slightly decreases hardness and strength with almost constant ductility.