Porosity in Aluminum Alloy Castings

Abstract

The inclusions and impurities (such as oxides, carbide, defect, and so on) are formed mostly during the casting process. These inclusions and impurities reduce material properties because an increase in porosity has a tendency to form failure and corrosion of aluminum alloys. The effect of porosity on the fatigue life of AlSi9Cu3 cast alloy was studied, examining the effect of porosity size, distribution, and morphology on the fatigue behavior changes, using image analysis software. A comparison of the fatigue properties was made between material casted into a metallic mold and the material casted into a sand mold under the same conditions of gravity die casting. The fatigue properties were studied on equipment Vibrophores Amsler 50–250 HFP 5100 for material casted into a metallic mold and on Rotoflex for materials casted into a sand molds. The results show that porosity has the greatest detrimental effect on fatigue life. It was found that fatigue life decreases with increasing size of the pores surface. The experimental material casted into the metallic mold had about 98.78% smaller porosity size in comparison to the material casted into the sand mold; therefore, it showed better fatigue and mechanical properties.