Thermal Optimisation Model for Cooling Channel Design Using the Adjoint Method in 3D Printed Aluminium Die-Casting Tools

In the present study, the adjoint method is introduced to the optimisation of the corner cooling element in two baseline cooling designs for a mould cavity, as examples of the Aluminium metal die-casting process. First, a steady thermal model simulating the Aluminium die-casting process is introduced for the two-corner cooling design scenario. This steady model serves as the first iteration of the optimised model using the adjoint method. A dual-parameter objective function targets the interfacial temperature standard deviation and pressure drop across the internal cooling region. For both design cases, multi-iterative deformation cycles of the corner cooling configurations result in optimised designs with non-uniform cross-section geometries and smooth surface finishing. Numerical simulations of the resulting designs show improvements in uniform cooling across the mould/cast interfacial contact surface by 66.13% and 92.65%, while the optimised pressure drop increases coolant fluid flow by 25.81% and 20.35% respectively. This technique has been applied to optimise the complex cooling system for an industrial high-pressure aluminium die-casting (HPADC) tool (Zeng et al. in SAE Technical Paper 2022-01-0246, 2022, [1]). Production line experience demonstrates that the optimised designs have three times the operational life compared to conventional mould designs, providing a significant reduction in manufacturing and operation costs.