Comprehensive modelling, analysis and optimization of furan resin-based moulding sand system with sawdust as an additive

Abstract

Scarcity of high-cost silica sand, casting defect such as hot tear in hard moulds and casting ejection problem after solidification are the key industrial problems. Sawdust is a by-product of wood working industries, and economic disposal of sawdust in these industries is a growing concern to the wood industries. The present work utilized sawdust as an additive in preparing mould cavity for casting applications. Sand mould properties such as compression strength (CS), mould hardness (MH), gas evolution (GE), permeability (P) and collapsibility (CP) will have good impact on the quality of castings. The effect of variables, namely quantity of resin, hardener, sawdust and setting time, on no-bake furan-bonded sand system is studied in the present research work. The experiments are conducted as per design of experiments, and the data are used to investigate the effect of individual and combined parametric contributions towards responses and establish nonlinear input–output relationships. All nonlinear regression models (that is, input–output relationships) are found to be statistically adequate. The input–output relations are analysed and presented for each of the response with the help of surface plots. Further, the models are found to predict the output close to the experiment (target value). The grand average value in predicting responses is found to be equal to 5.03%. The multi-objective optimization of responses with conflicting nature (minimize: GE and CP; maximize: CS, P and MH) is carried out with the help of global fitness function values determined using genetic algorithm, particle swarm optimization, teacher–learner-based optimization and JAYA algorithms. The optimized values of process parameters that resulted in best set of responses are found to be equal to 60 min, 2.01%, 0.6% and 0.93% for setting time, quantity of resin, hardener and sawdust, respectively. Two automobile coupling parts are cast by pouring molten aluminium into the mould cavity with the optimized and non-optimum sand mould conditions. Further, these two cast components are tested for their quality characteristics, such as surface finish, yield strength, hardness, density and secondary dendrite arm spacing. It has been observed that the quality characteristics of castings produced in mould with optimized parameters are found to be much better.