Novel Experimental Method for Metal Flow Analysis using Open Molds for Sand Casting

Metal casting is one of the most widely used manufacturing methods, producing many of the goods used in everyday life. Recent innovations in additive manufacturing (AM) have allowed for more complex mold and rigging designs to produce higher-quality castings. One of the limiting factors preventing widespread adoption of these complex designs, however, is the inability to fully visualize and characterize the metal flow in these molds. This paper examines the use of open molds to evaluate liquid metal flow to better understand the flow characteristics that will ultimately influence casting performance. The study investigated two types of open molds along with two types of cameras to find the best method for evaluating the melt flow. The open molds used were direct 3D sand printed molds, and green sand molds made with AM patterns. The cameras used were a camera with a higher optical magnification but lower frame rate, and a camera with no optical magnification but a higher frame rate. The video from both cameras was processed using a video analysis algorithm to identify the melt head and calculate its change in position and velocity along the path of the runner. Additionally, the results from the experiments were compared against computational fluid dynamics (CFD) simulations, showing that CFD underpredicted the melt head velocity by 58%. Findings from this study can complement CFD models for evaluating mold design. Additionally, new training tools can be developed using this method to improve pouring control and consistency for foundries.