Runner size dependency of tensile strength in AA6063 aluminium alloy sand castings

This study investigates the influence of varying runner sizes in sand casting gating systems on the mechanical performance of AA6063 aluminium alloy castings. Three distinct runner diameters (15 mm, 20 mm and 25 mm) were designed using CAD tools and fabricated via FDM 3D printing. Cast specimens were produced using green sand moulds, and tensile properties were evaluated according to ASTM B557M using a Universal Testing Machine (UTM). The findings revealed a direct correlation between runner size and tensile strength, with the 25 mm runner yielding the highest tensile strength of 97.88 MPa, compared to 70.55 MPa and 51.6 MPa for 15 mm and 20 mm runners, respectively. The results emphasize the critical role of gating design in optimizing mechanical performance, providing valuable insight for improving aluminium casting process.