Effect of Pouring Temperature and Water Cooling on the Microstructure of Ingots Produced by Cooling Slope Casting Technique

Abstract

The cooling slope (CS) casting is the simplest and cheapest technique for producing feedstock materials with non-dendritic microstructure required for semi-solid metal (SSM) processing methods such as thixoforming. In the present investigation, the effect of the pouring temperature and the water cooling on the thixotropic microstructure of commercial A319 Al-Si cast alloy was studied. The results showed that increasing the pouring temperature slightly reduces the bulk porosity of the CS ingots. The ingots poured with water-cooling exhibited slightly lower porosity content than those poured with without water-cooling. Generally, it has been found that the primary α-Al grains have generally higher shape factor near the edge of ingot than the middle and center. Ingots poured with water-cooling exhibited lower grain size and shape factor than those poured without water-cooling. Increasing the pouring temperature increases the size α-Al grains. Ingots poured with water-cooling exhibited higher hardness values than those poured without water-cooling.