Jesper Thorborg, Jörg Klinkhammer and Heinz-Jürgen Gaspers, Aachen
Structural aluminum parts used in the automotive industry are widely produced by the High Pressure Die Casting process, HPDC. The process is mainly used because of the high production rate and the possibility to manufacture complex parts with high requirements to shape and tolerances. Due to microstructural requirements and mechanical performance of the aluminum parts, the HPDC process is in many cases followed by a sequence of heat treatment steps, which govern the final properties of the parts before assembling into larger structures.
During casting and heat treatment the cast material is thermally loaded in a wide temperature range, starting from the casting temperature going through the solidification interval and during solid state cooling down to room temperature. Depending on the chosen heat treatment process, the temperature is subsequently changed in several steps by reheating the parts and holding the temperature for some time before finally cooling down to room temperature again. Depending on the design of the part, the process control, and the choice of cooling and quench parameters, the level and change in temperature lead to thermal gradients and conditions which have a high influence on how the stresses and deformations evolve during the multiple manufacturing steps. This article presents a state of the art modelling approach where results from the casting process are considered in the subsequent heat treatment calculation. This fully integrated approach in MAGMASOFT® supports the work flow of Autonomous Engineering, where virtual experiments are used to optimize mechanical properties and performance, to improve quality and to reduce costs and production time. The benefits from analyzing the full manufacturing process chain are significant when dimensional tolerance problems are identified or can be resolved before tooling is manufactured or even in the design phase of the component.
The complete publication is available in the linked PDF.
Integrated modelling of deformations and stresses in the die casting and heat treatment process chain