Abstract
The green sand-casting process has many benefits over other casting processes, such as low entry cost, minimal waste footprint, and comparatively competitive molding rates when fully automated molding processes are used. As our aluminum foundry adopted these high-speed green sand molding processes, we uncovered a lesser published defect regarding surface porosities that affected areas of significant modulus with extended solidification times. Many foundries that adopted the automated green sand molding process accepted this impediment to producing high-quality products as a by-product of green sand limitation. Many of them tried to mitigate surface porosity through traditional means, such as the use of strategically placed mold chillers, dangerously low pouring temperatures, and costly in-process rework. This settlement, although perhaps justified by popular opinion, did not reflect the opinion of BQC Foundry. Consequently, BQC Foundry decided that the time had come to find a solution to this surface porosity. BQC worked with our supply partner of casting simulation software while we armed ourselves with the work of John Cambell to form an alliance wherein, we could study the development of porosity formation at the mold/metal interface while exploiting our competitive advantage using simulation modeling. The information developed through simulation and functional tests will be reported in this paper.
