Aluminum alloys have inherent tendencies to produce casting defects caused by alloying or metal melt flow inside the mold. The traditional detection method for these defects includes reduced pressure tests, which assess metal quality in a destructive manner. This leaves a gap between metal quality assessments and tensile test correlations. Computed tomography (CT) scans offer crucial assistance in evaluating the internal quality of castings without damaging the structure. This provides a valuable opportunity to couple mechanical tests with numerical methods such as finite element analysis to predict the mechanical performance of the alloy. The present study aims to evaluate the internal quality of cast aluminum alloys using CT scans and to correlate the defect metrics obtained from CT scans with mechanical test results. The Gurson-type material model and finite element methodology have been used to validate the correlation studies. Therefore, we propose a more holistic approach to predicting the behavior of metals by coupling damage models with CT scans and mechanical tests. The study investigates several CT metrics such as the defect volume, total defect surface, biggest defect surface, and projected area of defects. The conclusion reveals that CT scans provide crucial assistance in evaluating the internal quality of castings, and CT defect metrics can be used to build correlations between mechanical tests and CT evaluations. The study also suggests that the concept of adjusted representative material yield parameter (ARMY) or computed representative material yield parameter (CRMY) can be used to correlate CT metrics with mechanical strength in cast materials and parts for a given aluminum alloy. Overall, the study proposes a more comprehensive methodology to assess the quality of cast aluminum alloys and couple the quality to mechanical performance.

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.