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Copyright  2019 American Foundry Society https://doi.org/10.1007/s40962-019-00391-4

Abstract Permanent mold metal casting processes use tempering with oil, water or air as state-of-the-art method for temperature control of certain regions. This approach aims at either creating certain temperature gradients inside the die thus leading to better casting quality or cools down critical hotspots in order to decrease cycle times or increase service life. In order to perform an investigation on the influences of oil tempering on a permanent die and the solidification of the aluminum alloy A356, an experimental setup is used with measurement instrumentation for recording temperatures inside the melt and die as well as recording the movement of the die and the casting, thus enabling a gap width determination and measuring the contact pressure present on an inner core. A thermomechanical simulation of the solidification also is performed

representing the processes occurring inside the experimental setup and extending the available data beyond the information locally provided at the experimental measuring positions. This approach allows for an evaluation of the influence of oil tempering on the solidification process, the thermal conditions inside of the casting, die, and core, and describes the behavior of a one-sided cooling of a comparatively large melt volume as well as the influences on a region with two-sided heat extraction affecting a smaller melt volume.

Introduction and Background

permanent mold casting system, temperature control of the die is state-of-the-art. Here, either the heating of certain areas or a cooling can be used to both control the heat balance and reach desired temperatures faster. This paper presents the effects of variation of die temperature control temperatures applied in a gravity die casting process using the A356 (AlSi7Mg0.3) cast alloy. As the changes of the microstructure due to differences in cooling rates have been sufficiently documented as well as the impact of the cooling rate on grain refinement and modification,6 the discussion’s focus will be on the process-related influences. A thermal analysis will be performed in order to identify the characteristics of the solidification.7,8 This way the exact changes and characteristic effects that can be transferred to other castings and processes shall be depicted. For this, an experimental measurement as well as a thermomechanical simulation using the software Abaqus will be performed delivering results beyond the local measurement positions or limitations of the measurement setup.

The casting process represents a complex interaction of numerous physical effects. Two main factors for influencing the casting process exist: On the one hand, there is the possibility of influencing the present metallurgy which is about changing the material and casting properties of the casted alloy. Depending on which alloy (system) is used, the means and possibilities for change differ, but for an Al– Si alloy, grain refinement and modification would be th