EVALUATION OF MOULDING PROPERTIES OF SAND IN NIGER STATE FOR ALUMINIUM CASTING AND OTHER FOUNDRY APPLICATIONS

Abstract

ABSTRACT Evaluation of moulding properties of sand in Niger State for casting and the effects of the sand mould on mechanical properties of aluminium cast is presented. The moulding properties includes; Permeability, Compactibility, Moisture Content, Green and Dry Strengths. Sand samples from five locations in Niger State, Zungeru, Tungan Mallam, Wuya, Gidan Mangoro and Tagwai Dam area villages were collected and evaluated according to the American Foundry Society (AFS) standard. Mechanical (Tensile and Hardness) and Metallographic tests were carried out on the aluminium cast specimen obtained from the five different sand samples to verify the sand test results. All the results of the five different sands evaluated were compared with that of satisfactory standard mould property ranges for sand casting, the values of result of the five sands evaluated were found to be out of range with that provided for aluminium alloy casting. Mechanical and Metallographic tests of the aluminium samples produced from the five different sand were carried out to validate the results from the sand tests. The sand tests results gave values that ranged between for Permeability 72.08 – 96.85, Green Compressive Strength 12.50 kN/m2 – 48.67 kN/m2 and 76.00 kN/m2 – 116.67 kN/m2 and Dry Compressive Strength 85.00 kN/m2 – 650.00 kN/m2, While the satisfactory mould property ranges for sand casting for aluminium are Permeability 10-30, Green Compressive Strength 50 – 70 kN/m2, Dry Compressive Strength 200-550 kN/m2. The sand test results however of Wuya, Zungeru and Tagwai Dam area villages were found to be within the range for casting Heavy Grey Iron as provided by standard mould property range for sand casting, while the result of Gidan Mangoro village was in the range for Malleable Iron castings. Tungan Mallam sand results did not provide values within the range provided by the standard mould property range for sand casting in its natural state as provided in the table of standard.