Influence of Sprue Layout on Microstructure, Porosity, And Mechanical Properties of Aluminum Pipe Casting with Red Sand Molding Write

Abstract

This study investigates the effect of sprue position on the characteristics of recycled aluminum castings, focusing on chemical composition, microstructure, porosity, and hardness. Recycled aluminum from various remelted components was used to promote sustainability in metal casting. Three sprue configurations were tested—top (A), side (B), and center (C). The analysis included chemical composition (ASTM E-1251), microstructure via metallographic microscopy (ASTM E-3), porosity observation, and Brinell hardness testing (ASTM E-10). The results showed a composition of 81.20% aluminum, 11.80% silicon, and 4.50% iron, classifying the material as an Al–Si alloy. The sprue position significantly influenced casting quality. Sprue A achieved the highest hardness value (99.48 BHN) and the finest microstructure with minimal porosity. In contrast, positions B and C had lower hardness values (79.04 BHN and 74.11 BHN, respectively) and coarser microstructures, due to increased porosity. This study highlights the importance of sprue design in minimizing casting defects and improving the mechanical performance of recycled aluminum alloys.