IMPLEMENTATION OF EXPERIMENTAL DESIGN IN EVALUATING THE MECHANICAL PROPERTIES OF CERAMIC COMPOSITES

The influence of independent variables (firing temperature and residue content) on mechanical properties – hardness, compressive strength, flexural strength, compression modulus and energy at the break – of ceramic composites was investigated through experimental design. Microstructural evaluation using scanning electron microscopy (SEM) and mineralogical identification using x-ray diffraction (XRD) was also accomplished to understand the structure-property relationship. In analysing the observed data, variance analysis was employed to determine the statistical significance of the factors on the responses and regression equations showing correlations were developed. The observed data were shown to accept the null hypothesis for hardness, compression modulus and compressive strength, while flexural strength and energy at break rejected the null hypothesis judging by the p-value. The flexural strength showed a good correlation, but the influence of firing temperature and residue was minimal. However, both factors' square was shown to influence the flexural strength considerably. The study presents a systematic way to understand causal relationships, ensuring that product specifications and quality are met.