Experimental Investigation of Heat Transfer Coefficient of Aluminium 6061 Casting Shapes Using Green-Sand Mould,

Abstract

It is necessary to produce shapes such as plate and bar using casting process for developing indigenous technology of green sand mould. To have the knowledge of solidification time and temperature gradient which are governed by Heat transfer coefficient (HTC) will help to understand required temperature for achieving desired cast shape. The shapes employed for the study includes rectangular plate, square bar and cylindrical bar. Experiment was conducted and values of various temperatures were obtained using electronic temperature recorder. The solidification time of the cast shows that solidification rate is faster in plate when comparing to other shapes. The casting of shapes that involves using aluminium alloy 6061 solidified within 105 seconds after pouring of the molten metal into mould cavity and also plate was the first to solidify. The mould constant obtained for the sand mould was 3. The experimental result shows that thermal conductivity of the alloy was 102.3 WmK and the value was within range of stated value (85 - 173 W/mK) by ASTM. Heat transfer coefficient (HTC) in the cast objects was 101.1 W/m2K.