JME_V3_N2_RP4 Girendra Bhati Sudhir Kumar Ajay Kumar Daizy Rajput Journal on Mechanical Engineering 2249 - 0744 3 2 21 32 Expandable Polystyrene Pattern, Zircon Flour, Mullite, Potassium Silicate, Sodium Silicate, Density, Viscosity, AHP In the present scenario, the dimensional accuracy and surface roughness of casted complex shape products have become a critical issue to reduce machining cost in terms of time, price and scrap materials. So, different types of casting processes have been introduced. One of the important casting process is Investment Casting Process with Expandable Polystyrene Pattern, instead of wax pattern. In this casting process, the shell is made by decomposition of Expandable Polystyrene pattern with the application of heat. During the foam removal process, several problems have been created such as bending, expansion, distending and crack of the shell. In this paper, Zirconium Flour and Mullite sand (Aluminium-Silicate) have been introduced as coating materials with different ratio, with binder as Sodium Silicate and Potassium Silicate. Twelve samples have been prepared and the densities and viscosities of each sample are calculated. Twelve shells are also generated. For selection of best shell material composition, Analytical Hierarchy Process (AHP) is used. Sample 7 has the best result. Also, Potassium Silicate is found better than Sodium Silicate as binder, to reduce distending of shell, cracks, etc. and to increase surface finish and strength to weight ratio of shell. February - April 2013 Copyright © 2013 i-manager publications. All rights reserved. i-manager Publications http://www.imanagerpublications.com/Article.aspx?ArticleId=2211