Residual stresses in high pressure die castings

Roger Svenningsson, Håkan Svensson



Residual stresses in castings are important to consider during the design stage due to its influence on the mechanical behaviour. Residual stresses are however generally neglected during the design and a stress free state is assumed as initial condition for simulations. This paper presents results from measurements and simulations of residual stresses in an aluminium high pressure die casting. Simulations were performed as coupled thermal-mechanical simulations and were compared with measured stresses at different positions of the casting using the hole drilling method.

From the measurements a large scatter in compressive stresses was found at the surface at all positions evaluated. A minor sensitivity analysis regarding heat transfer related parameters was performed using simulations. From the simulations it was concluded that a high heat transfer coefficient together with a highly resolved Finite Element Model the first millimetre gave results in good agreement with the measurements.