Numerical analysis of liquid fraction in solid- liquid phase transformation of semisolid alloy

AbstractThe non-linear mathematical expression of liquid fraction in solid–liquid phase transformation of semisolid alloy was derived by thermodynamic equations, and the numerical solution of the non-linear mathematical expression was obtained by the Gauss Newton iteration algorithm. The solid–liquid phase transformation of hypereutectic Al–20Si–3Fe–1Mn–4Cu–1Mg alloy was studied by differential scanning calorimetry, and it was used for the expression reliability validation and compared with the Scheil linear regression expression. The results showed that the liquid fraction of the semisolid alloy was not increased linearly with the heating temperature increasing, but increased non-linearly, which was not consistent with the Scheil expression, and the growth rate of liquid fraction was not entirely the same in different temperature ranges. The non-linear mathematical expression data fit well with the experimental data, and the non-linear mathematical expression had a smaller discrete degree and higher cred...