The characterization of porosity and its relationship with externally solidified crystal in a high-pressure die-cast AlSi10MnMg alloy via a laboratory CT technique

The characterization of porosity and its relationship with externally solidified crystal (ESC) in a high-pressure die-cast AlSi10MnMg alloy is investigated using a laboratory CT technique. Results show that in the bar sample, pores with a high sphericity exhibit a radial distribution under a higher fast shot speed. The appropriate decrease of fast shot speed reduces the porosity but increases the proportion of irregular shrinkage. Without applying intensification pressure, the porosity is rapidly increased and further decreasing fast shot speed, large-size pores are formed in ESC interdendritic gap. In sheet sample, the decrease of fast shot speed increases the porosity and promotes the formation of large-size shrinkage and it is related to the enrichment of ESC.