Effect of Cooling Rates on the 3D Porosity of Permanent Mold Castings Measured by Computed Tomography

摘要

The 3D porosity obtained at different cooling rates in permanent mold castings was investigated. First, an aluminum alloy (10.4 silicon) was poured into permanent mold castings, and tensile samples that had solidified at different cooling rates were extracted from different areas of the molds. The porosity of these tensile samples was evaluated by computed tomography scanning, and the effect of the cooling rate on percentage volumetric porosity and tensile properties was investigated. The 3D volumetric porosity ranged between 0.004 and 0.023 in L-shaped samples with higher cooling rates, while it was between 0.012 and 0.066 in L-shaped samples with lower cooling rates. It was found that the cooling rate profoundly affected the volumetric porosity, and better mechanical properties were reported for higher cooling rates. This research is one of the first investigations into quantifying the 3D porosity of permanent mold aluminum alloy castings.