Determination of liquidus temperature in Al-Si and Al-Si-Mg alloys using a single-pan scanning calorimeter

A single-pan scanning calorimeter has been used to measure the liquidus temperatures in Al-Si and Al-Si-Mg alloys. Problems with the conventional tangent method for determining the liquidus temperature from calorimetrical measurement are discussed when sample enthalpy change does not vary linearly with temperature. A new method is proposed to calculate the liquidus temperature from measured enthalpy data. The calculated liquidus temperatures using the new method are lower than those determined using the tangent method.