Advanced Predictive Modelling for the Optimization of Graphite Crucible Pots from Kaolin Clay and Functional Additives

Abstract

This research investigates the optimization of graphite crucible pots made from kaolin clay and functional additives. The study demonstrates that kaolin clay enhances mechanical strength through ceramic bonding while preserving high thermal conductivity from the graphite matrix. Various additives were evaluated to customize the crucible properties, including silicon carbide, granite, borosilicate glass powder, and sodium silicate binder. Predictive models were developed alongside Response Surface Methodology (RSM) optimisation to formulate graphite crucible compositions with optimal mechanical strength and thermal shock resistance. Furthermore, Finite Element Analysis (FEA) was used to simulate thermal and mechanical stresses experienced by the crucibles during operation. The results reveal a strong correlation between experimental and predicted values for optimization, highlighted by high regression coefficient (R²) values. The optimal composition was determined to be 43.5721% kaolin clay, 3.31722% granite, and 7.05904% borosilicate glass, yielding a crucible with a hardness of 55.78, compressive strength of 25.02 MPa, thermal conductivity of 3.32 W/mK, thermal expansion of 2.3760E-5 per °C, and a density of 2.35424 g/cm³. FEA demonstrated that this optimized crucible can withstand temperatures exceeding 2000 degrees Celsius. Comparative analysis showed that the optimized graphite composite crucible significantly outperformed the commercial EQ-CB-G001015-LD graphite crucible, exhibiting higher density and superior temperature resistance, thereby reflecting enhanced material properties. The findings provide valuable insights into the formulation and design of composite crucibles with improved performance, presenting promising advancements for industrial applications.