Study of the effect of green sand properties on thermal conductivity variation of sand mould

Abstract Thermal conductivity of moulding sands is very poorly known. In addition, the study of thermal conductivity variation of moulding sand as a function of its properties is a crucial step in the prediction of moulding defects. So, this study investigates the effects of moisture content, compactibility and permeability of green sand on its thermal conductivity variation, with a specific focus on the combination of bentonite, sand and water for thermal characterization of the transient hot-bridge (THB) method. Three levels of active clay content were selected: 8.1%, 8.98% and 10.03%. For each level of active clay, different mixes were made by varying the amount of added water. Compactibility, permeability and thermal conductivity tests were carried out for each combination of active clay and moisture contents. The experimental results show that thermal conductivity increases with water content and compactibility for different active clay contents, whereas thermal conductivity decreases with permeability, and this variation is highly significant especially for 8.07% of active clay content.