Optimization of green sand process for quality improvement in castings by using combination of Taguchi Techniques-GRA-PCA

Abstract

The castings produced by a sand casting process have multiple quality features. The quality of a casting always depends upon proper controlling of enormous parameters involved in the process as well as proper combination among these parameters, while some of the defects are found persisting and difficult to avoid. Controlling the process to avoid the rejections of cast components due to the presence of such persisting defects mainly depends on the right understanding of the parameters associated with it. In the work presented in this paper, the primary focus is on the optimization of essential parameters of the green sand process to minimize the occurrences of these persisting defects in gray iron automotive components through experimental investigation using effective approach. The study applies the Taguchi’s ‘Design of Experiments’ approach in combination with grey relational analysis (GRA) and principal component analysis (PCA) for determining the optimal level of parameters to minimize the defects Shrinkage porosity (SP), blowholes (BH), sand inclusion (SI), scabbing (SC) and low hardness (LH), which are persisting in the foundry industry producing cylinder heads and other castings required in the automotive, factory situated in central India. Optimal levels of parameters were determined by the single grey relational grade (GRG) obtained from GRA for overall improvement in multi-quality characteristics. PCA is used to determine the corresponding weighting values of each performance. The outcomes of this study assure that the approach used in this work, is useful to foundry industries to minimize the persisting casting defects.