Comparative investigation of partial cooling methods for induction heating of hybrid bulk components for hot forming

Abstract

Abstract. The novel Tailored Forming process chain enables the combination of crucial properties of different materials by manufacturing hybrid components. Thereby, the limitations of monolithic components are surpassed. However, manufacturing hybrid bulk components introduces new challenges for hot forming. For example, when combining steel and aluminium, the main challenge is establishing and maintaining a temperature gradient in the component to match the differing flow stresses of the materials for a successful forging. For establishing the gradient, a particular heating strategy, including inductive heating of the steel and parallel partial cooling of the aluminium, is necessary. After reaching the target temperature, the heated component has to be transferred to the forging die by a robot while maintaining the essential temperature gradient. Therefore, a portable spray nozzle cooling system attached to the robot's end effector was designed in former work. This paper aims to validate spray nozzles for establishing a temperature gradient in a hybrid workpiece with a particular heating strategy compared to a currently used immersion cooling. For the validation, the nozzles will cool a hybrid steel aluminium shaft, whereby the nozzles' operation parameters influence on the temperature gradient will be investigated. Finally, the performance of the nozzles will be compared against the currently used immersion cooling.