Mathematical modelling and macro casting analysis of complex casting sections according to the unit area method

The Unit Area approach is a geometry-based mathematical modeling with shape recognition feature that can be used to plot two-dimensional solidification isotherms. In this study, the applicability of this modeling to complex casting parts was investigated. For this purpose, three different casting parts were selected, sections suitable for analysis were taken, these sections were transferred to the AutoCAD drawing program and drawing the solidification isotherms on each section with the help of a simple isotherm calculator based on the Unit Area approach was explained in detail. Accordingly, using the formulas of square outer corners, square internal corners, cylindrical round surfaces and cylindrical planar surfaces based on the Unit Area approach, the relevant corner isotherms are drawn using the formulas, whichever part of the sections fits which formula, and then these corner isotherms are joined by using the closest tangent and parallel joining methods together. After the drawing of the solidification isotherms based on the Unit Area approach have been completed, the remaining large gaps have been defined, and the locations of possible macro casting defects that may occur during solidification have been investigated. The solidification isotherms obtained for each part and the defect points found were compared with the Porosity and Hot-Spot FSTime simulation results provided by the Magmasoft® casting simulation software for the same casting shapes. Accordingly, macro defect locations given by the Unit Area approach and Magmasoft porosity results are partially compatible. The defect locations found according to the Unit Area approach can determine the location of the pores, but cannot fully determine the effect of porosity to spread to other parts of the part. On the other hand, there is a very high correlation between the macro defect points provided by the Unit Area approach and the hot-spot locations provided by the Magmasoft® casting simulation program. In order to further increase this correlation, increasing the number of sections to be analyzed according to the Unit Area approach, in proportion to the complexity of the cast parts, gives more accurate results. The Unit Area approach provides approximate results on the shape of the defect locations, but it can show their exact location with greater precision.