2026 Kweon Al7 5Si Cooling Curve Solidification

Shrinkage cavities and micro-pores occurring in castings are major causes of quality degradation and increased costs. Accurately predicting their occurrence through solidification models requires reliable calculation of the solid fraction changes during solidification, of the latent heat of solidification, and of the characteristic temperatures such as the liquidus, eutectic, and solidus temperatures. This study aims to investigate how various smoothing methods applied to thermal analysis data affect calculated results at three distinct cooling rates, thereby improving the accuracy of shrinkage defect prediction models for aluminum alloys. The methodology involved applying several smoothing techniques, including mean smoothing, Gaussian smoothing, Savitzky–Golay filter, and polynomial regression, to experimental thermal analysis data of an Al–7.5 pct Si alloy cast in steel cups of varying diameters. Critical temperatures were determined using first and second time derivatives of temperature, with Newtonian and Fourier analyses employed to calculate the fraction solid evolution and latent heat as a function of cooling rate. Results indicated clear differences in time evolution of fraction solid, emphasizing the importance of selecting appropriate methods for more accurate microporosity predictions in computer models. This comprehensive analysis provides essential values for improved defect prediction in casting processes.