Aluminum castings can contain pinholes caused by porosity from a number of sources, including the presence of gas or from shrinkage. These pinholes, although normally small in size and number, can greatly influence the properties of the casting, often resulting in the scrapping of the part. While many factors are involved in the formation of porosity in aluminum castings, such as the influences of hydrogen and aluminum oxide (A12O3) on gas-porosity, this study investigates the effects of cooling rate and section thickness. These factors are studied by using a sand cast aluminum bar with different section thicknesses which undergo different cooling rates during casting [1,2].
展开▼
