Studies on Porosity of Al-4.5%Cu-2.5pTiB<sub>2</sub> <i>In Situ</i> Composites

Abstract

In the present paper, experimental investigation as well as computer assisted casting simulation technique is used to analyse the effect of different parameters like properties of sand and molding methods to predict defects in green sand casting. An attempt has been made to obtain the optimal settings of the moulding sand and mould related process parameters for the casting of Al-4.5%Cu-2.5TiB2 composites. The green sand related process parameters considered in the study are moisture content, green compressive strength, permeability of moulding sand and mould hardness. In the fabrication of composites, porosity is greatly influenced due to improper gating/riser system design. The analysis of porosity is performed using Auto-CAST simulation technique by the introduction of a new gating system designed and the solid model was developed for sand mould cavity. A number of iterations using Auto-CAST simulation software were performed for mould filling and solidification analysis to reduce the level and intensities of porosities in cast Al-4.5%Cu-2.5TiB2 composite. With new gating and feeding system design, reduction in porosity and improvement in yield is observed. The simulation results were found to be in good agreement when compared with the experimental trial.