Assessment of Mechanical Behaviors of Sand Cast Al-Mg7-Cu2 Aluminum Alloy in Tilt and Vertical Gravity Casting Conditions

Aluminum alloys bears great importance and has found extensive usage area in industry especially in automotive. Ease of casting into complex shape favors their usage. The production method of these alloys has been crucial to obtain the required mechanical and physical properties since their susceptibility to form defects in the form of oxides and various defects is considerably elevated. As high magnesium and copper containing aluminum alloys tends to increase defect formation, in order to improve the overall quality of cast parts, effective melt treatment and optimal pouring processes are essential. This study focuses on the effect of degassing bubble size in melt treatment and vertical versus tilt pouring techniques at casting stage. We evaluate three melt treatment parameters: no degassing, small bubble degassing, and large bubble degassing. The pouring techniques as tilt angle application and vertical pouring have been examined. Under various pouring conditions, the mechanical characteristics of T6 heat-treated custom composition AlMg7Cu2 alloys are compared. Alloying decision has been taken to incorporate as much defect as possible to capture effects of defects due to melt treatment and pouring conditions. Computed tomography scans, SEM analyses of fracture surfaces, and evaluations using optical microscopy have been performed for quality assessments. Basic comparison of tensile testing with CT scans have been provided. Variation of properties at different bubble size and pouring conditions have been provided. The findings emphasize the significance of using tilt pouring with lower hydraulic jump and less turbulence in metal melt flow in mold filling. Moreover, reducing bubble size during degassing has also been found crucial and highly effective in order to achieve consistent mechanical characteristics.