Characterization of Foundry Sand Cores Bonded with Raw Nigerian Water Melon Seed Oil

Abstract

Raw oil extracted from Nigerian variety of water melon seed was used as sole binder for foundry sand cores. Specimens were characterized for foundry properties that included baked tensile, green and baked compressive strengths; baked collapsibility, green permeability, bulk density and shatter index to determine the efficacy of the oil in the absence of additives for core application. Except the baked collapsibility test that was carried out at a temperature of 600⁰C, other specimens were oven baked at 200⁰C and oven cooled before the tests. Green permeability and compressive strength tests were carried out on freshly moulded specimens. Standard foundry laboratory/workshop equipment available at Nigerian Machine Tools Company Limited, Oshogbo was used to conduct tests under standard conditions. Results showed that cores with compositional mix of 1-3% water melon seed oil had adequate foundry characteristics for production of classes II-V iron and steel castings. Cores bonded with the oil were unsuitable for classes I and II iron/steel and non ferrous castings including copper, aluminium and magnesium alloy due to the poor baked tensile strength and collapsibility values. Results of green permeability, shatter index and compressive strength of tested cores were very sufficient for casting both ferrous and non-ferrous alloys.

Keywords: Melon seed, oil, cores, baked, foundry, characteristics.