Performance analysis of cow dung as an eco-friendly additive material for sustainable moulding and casting

In the present work, an attempt is made to partially replace high cost silica sand with sustainable eco-friendly cow-dung. The practical utility of cow dung as an additive material that facilitates binding in sand moulds has been tested. The Taguchi method is used to plan and conduct nine experiments with three replicates each. Pareto analysis of variance study is performed to understand the practical significance of moulding sand variables, that is, percentage of cow dung, clay, water, and degree of ramming on sand mould properties. The conflicting multiple objective functions (maximize mould hardness, and minimize collapsibility and gas evolution) are optimized by utilizing the Data Envelopment Analysis Ranking (DEAR) method. The optimal parameters i.e. 6% of clay, 4% of water, 5% of cow-dung and 4 numbers of ramming strokes are obtained by applying a hybrid Taguchi-DEAR method. These parameters show the best moulding properties are: mould hardness 55, gas evolution 5.9 ml·g⁻¹, and collapsibility 470 g·cm⁻². Thereafter, a Lovejoy coupling made of aluminium is cast in the sand mould prepared with cow dung and without cow dung, with the optimum set of parameters. The mechanical properties, surface finish, and microstructure of the casting cast with cow-dung are better than that without cow-dung.