Fabrication of fused silica‐based cores by the gel‐casting method: Modeling by response surface methodology

Abstract

In this study, fused silica‐based cores fabrication via gel‐casting procedure was modeled via the response surface methodology (RSM). Zircon content, alumina content, and sintering time were selected as variables and the influences of these parameters on the characteristic of the prepared samples were investigated. Two series of experiments were organized; (i) evaluation and modeling of the sintered samples and (ii) evaluation and modeling of the samples which passed pouring‐simulation treatment. Mechanical strength, porosity content, and leachability were selected as the response parameters and the obtained numerical data were analyzed using the Minitab software. Based on the RSM principles, the main effects plots and contour plots were recorded and the system was studied by means of a statistical model. However, both series of samples were evaluated and mathematical regression equations were gained from the RSM technique for modeling the response parameters; MOR, porosity, and leachability. Results showed that in the sintered samples, the most effective parameters on the MOR, porosity, and leachability values were Al2O3 content, zircon content & sintering time, and zircon content, respectively. It is interesting that in the pouring‐simulated samples, the most effective variable on the response parameters was Al2O3 content.