Evaluation of effective baking conditions for grade 3 Nigerian Acacia species bonded foundry sand cores

Abstract

Abstract: The most effective economical baking conditions were determined for foundry cores bonded with the grade 3 Nigerian acacia species exudates. Silica sand base cores bonded with the material were oven baked at temperatures ranging from 160 to 250ºC for varying periods oven cooled and then subjected to tensile strength tests to ascertain the best baking conditions for different alloy castings. The experimental core specimens were in accordance with foundry test standard, shaped like figure number eight. They were tested with standard universal strength machine equipped with attachment for gripping the cores and an instantaneous meter from which the test values were read. The result were compared with established standard foundry core property table which showed that the class V iron/steel cores are best made with 3% acacia bonded silica sand baked at 160ºC for 1 h. For magnesium cores, sand bonded with 4.5% acacia baked at 160ºC for 1-2 h was optimum. For class IV iron/steel cores 4.5% acacia bonded sand baked at 180ºC for 1 hour was optimal. Sand bonded with 4.5% grade 3 acacia baked at 200ºC for 1.0-2.0 h was optimum for copper, aluminium, classes II and III iron/steel cores. Sand bonded with 8.0-13.0% grade 3 Nigerian acacia species baked at 200ºC for 1.5-2 h was found most effective for class I iron and steel cores