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Abstract
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The casting process involves pouring superheated molten metal into a mold with the desired shape. The next step is solidification, which includes a phase change from liquid to solid and subsequent thermal contraction during cooling, resulting in volume shrinkage. The heat balance plays a crucial role in determining these effects. The heat flow through the mold walls affects the rate of solidification, microstructure, and mechanical properties of the casting. The heat exchange with the mold also influences shrinkage defects, distortion, and residual stresses. Moreover, mold expansion or shrinkage due to heating and cooling cycles impacts the dimensional accuracy of the cast parts.
The heat transfer coefficient (HTC) is an important physical quantity in describing the potential heat exchange at the interface between two bodies. Several factors, such as mold temperature, contact pressure, gap formation, thermal conductivities of the materials, surface roughness, and applied coatings, influence the HTC. Determining appropriate HTCs throughout the casting process is essential for understanding underlying processes and accurately predicting solidification time, casting structure, defects, and mechanical properties [1,2].
In this work, the determination of HTCs present in regions with contact pressure and gap formation is performed based on a numerical solidification simulation. The determination of appropriate HTCs during the entirety of a casting process represents a focus on research and industry to lead to a higher understanding of the underlying processes as well as to more accurate predictions of the solidification time, casting structure, defects, and mechanical properties. Describing an entire casting process in a simulation is challenging, especially for the solidifying alloy. Understanding the material behavior in both the solid and liquid states and the processes and property behaviors during phase transition. This includes the solidification process and the mec
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