INVESTIGATION OF EFFECT OF FILLER MATERIALS IN ZIRCON FLOUR COATING USED IN EPC PROCESS

Abstract

Coating is one of the most important steps in the Evaporative Pattern Casting (EPC) Process. Stability in handling of the cluster during casting, specific gas permeability and removal behavior is the demand of EPC. In general zircon flour is used as a coating material in the EPC Process but it is very costly. In the present work, Refractory filler materials (Quartz and Siliminate,) and binders (Dextrin & Bentonite), have been used along with the zircon flour. Parameters such as density, viscosity, and dielectric constant, have been found for different combination of the developed mixture which in turn is used as a coating to pattern in the process. Response surface methodology (RSM) is used to fmd the various combinations of the samples. X-Ray Diffraction analysis (XRD) of the coating samples were done within the diffraction angle interval of 20 to 85°. The Scanning Electron Microscopy (SEM) has been used for powder particles morphology. Study of temperature, in the range from ambient temperature 20°C to 1000°C, on the mixture was determined using Differentially Thermal Analysis (DTA). The selection of appropriate model and the development of response surface models have been carried out by using statistical software, Design Expert (DX-7). The response surfaces are plotted to investigate the effect of input process parameters, zircon flour (A), Filler materials (B), and Binders (C) together with their second order interaction on the response characteristics. The Analysis of Variance (ANOVA) is performed to statistically analyze the results. Effect of the process parameters on the responses were also studied for all the sets.