Optimization of molding sand composition for quality improvement of iron castings

In the iron casting industry, the quality of the sand mold is important for foundry manufacturers to achieve high quality iron castings. The aim of this research was to optimize the proportion of bentonite and water added to a recycled sand mold for reducing iron casting waste using the following analysis techniques: a mixture experimental design, response surface methodology, and propagation of error. The effects of variation in bentonite and water added to a recycled sand mold on the properties of the molding sand were investigated. The iron castings were measured qualitatively using a stereo microscope and its surface hardness was also measured using a Rockwell hardness testing machine. The research concluded that the optimal proportion was 93.3 mass% of one-time recycled molding sand, 5 mass% of bentonite, and 1.7 mass% of water having a green compression strength of 53,090 N/m2 and a permeability of 30 A.F.S.