Thermophysical characterization of mould materials using parallel hot wire and needle probe methods at high temperatures

Thermophysical properties of moulding sands are very poorly known. So in this study two types of moulding sands: resin bonded sand and green sand were characterized using two methods combined in the same device: The needle probe (NP) and the parallel hot wire (PHW) methods. Numerical simulations were carried out and treated as numerical experiments to evaluate the precision of the different models. Four analytical models were used in the identification of the thermal conductivity: Slope and standard models and two complete quadrupolar models. The volume heat capacity was identified using the quadrupolar model of the PHW. For the resin-bonded sand, these properties were determined in the heating and cooling cycle. The results show that the volume heat capacity depends on the phase transformation of the silica sand. The thermal conductivity depends on the presence of the binder and a radiation heat model was developed to explain the increase of the thermal conductivity as a function of temperature.