THERMAL COMPATIBILITY STUDIES OF VARIABLE BODY AND GLAZE COMPOSITIONS FOR GLAZED CLAY BASED COOKWARE APPLICATIONS
Keywords:
Ceramic cookware, glaze, red clay, coefficient of thermal expansionAbstract
This study was focused on the development of a glazed red clay cookware with adequate thermal shock resistance for open flame cooking applications. Thermal compatibility of different red clay and fritted glaze compositions were investigated using thermal expansion and thermal shock resistance. Coefficients of thermal expansion and thermal shock resistance values of red clay bodies with different proportions of quartz were investigated. Commercially available lead free glazes were selected to satisfy the coefficient of thermal expansion and thermal shock resistance requirements. Thermal conductivity, modulus of rupture, and modulus of elasticity of each body and glaze were measured.Based on the test results, suitable red clay body and glaze compositions were selected and actual size cookware samples were fabricated.The red clay body with 25% quartz having a coefficient of thermal expansion of 60.31×10-7 K-1 and a thermal shock resistance of 0.97 kJm-1s-1, and the glazes having a coefficient of thermal expansion in the range of (49-51)×10-7 K-1 and thermal shock resistance in the range of (1.10-1.20) kJm-1s-1 could be effectively used to manufacture a glazed red clay cookware product. Hence it could be concluded that a suitable body composition for glazed cookware could be formulated by incorporating quartz in a certain proportion to kaolinitic type red clay.
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