Phase Fraction Prediction Based on Solidification Time on the Cooling Curve

The phase fraction plays a critical role in determining the solidification characteristics of metallic alloys. In this study, we propose a simplified method for estimating phase fraction based on the solidification time in cooling curves. The method was validated through experimental analysis of Al-18wt%Cu and Fe42Ni42B16 alloys, where phase fractions derived from cooling curves were compared with quantitative microstructure evaluations using computer-aided image analysis and the box-counting method. Results demonstrate strong consistency between the estimated phase fractions and experimental measurements, confirming the method’s reliability. The present method is easier operating, since it does not need derivative and integrals operations compared to Newtonian thermal analysis and Fourier thermal analysis methods. Furthermore, two key relationships deduced from the cooling curves were identified and analyzed: V/Rc=D/ΔT and RΔt=constant. These findings establish an operational framework for quantifying phase fractions and solidification rates in rapid solidification.