Impact of Top Mold Slope on Defect Formation in Gravity Casting of Aluminum Alloy

Abstract

This research investigates the impact of varying the slope of the top mold in the gravity casting process of aluminum alloy (A356). The casting mold slopes were adjusted to 7°, 12°, and 17° angles, and the study integrates software analysis (Altair, 2021.2) with physical examinations to assess potential defects in the casted products. The findings from both approaches exhibit a consistent pattern, revealing notable defect porosities in molds with slopes of 7° and 12°. Radiography examinations provide insights into defect distribution within the hub wheel rim, particularly pronounced in molds with slopes of 7° and 12°. This observation suggests that disturbances in air and heat distribution impede the solidification process within the mold. Metallography profiles further highlight the presence of phases α (Al), β (Si), and the eutectic region in the casted product. Defect severity is prominently manifested in a fractured profile, particularly for products cast with a 7° slope. In contrast, a higher slope of 12° results in localized porosities and effectively mitigates defect distribution. The most favorable outcome, devoid of substantial defects, is achieved with a 17° mold slope, successfully passing stringent quality checks.