Ceramic Cookware Composition for Induction and Thermal Shock Resistance

The patent applies parameter changes by precisely controlling the ceramic paste composition (quartz 10-25%, kaolin 25-50%, magnesium carbonate 10-25%, aluminum oxide 10-25%) and firing parameters (temperature 1360-1450°C, time 2-6 hours) to achieve the desired cordierite content and thermal expansion coefficient. This systematic parameter optimization allows achieving low thermal expansion (28-34 ppm/°C) within a reasonable firing time frame.

The patent uses composite materials by creating a ceramic paste composed of multiple specific ingredients (quartz, kaolin, magnesium carbonate, aluminum oxide) that work together during firing to form cordierite as the primary crystalline phase. This composite approach ensures both low thermal expansion and acceptable firing time by leveraging the synergistic effects of the constituent materials.

The patent applies parameter changes by optimizing the firing temperature range (1360-1450°C) and duration (2-6 hours) to achieve complete vitrification and minimal porosity. The specific composition parameters (particularly the balance between quartz, kaolin, and fluxing agents like magnesium carbonate) are tuned to ensure low water absorption (<0.5%) is achieved within an energy-efficient firing window.

The patent applies local quality by ensuring uniform distribution of the ceramic paste components before firing, which promotes consistent densification and vitrification throughout the product. This uniformity allows the entire piece to reach the desired low porosity state simultaneously, reducing the overall firing time and energy consumption compared to non-uniform materials that would require longer firing to achieve the same result throughout.

The patent applies the intermediary principle by introducing an electrically conductive layer (such as a metallic coating or conductive ceramic layer) on the bottom surface of the ceramic container. This conductive layer acts as an intermediary that enables induction hob compatibility by generating eddy currents when exposed to the induction field, while the rest of the ceramic body maintains its traditional properties. This localized addition minimizes overall process complexity.

The patent applies local quality by applying the electrically conductive layer only to the bottom surface of the container where induction heating is required, rather than making the entire container conductive. This localized treatment achieves induction compatibility while minimizing the impact on the overall manufacturing process and maintaining the aesthetic and functional properties of the ceramic body.

The patent applies composite materials by formulating a ceramic paste that contains multiple specific ingredients (quartz for low thermal expansion, kaolin for structural integrity, magnesium carbonate and aluminum oxide for cordierite formation). The resulting cordierite-rich ceramic (40-60% cordierite) combines the low thermal expansion properties of cordierite with the mechanical strength contributions from corundum and other crystalline phases, achieving both multi-heat-source compatibility and adequate mechanical strength.

The patent applies parameter changes by carefully adjusting the composition parameters (ratios of quartz, kaolin, magnesium carbonate, and aluminum oxide) and firing parameters to achieve an optimal balance between thermal expansion properties and mechanical strength. The cordierite content is controlled at 40-60% to ensure low thermal expansion while maintaining sufficient mechanical integrity for cooking applications.