The Mechanism of Cracking During the drying process, moisture evaporates from the inside out, causing the ceramic body to shrink. If the drying speed is too fast or uneven, localized stress concentration occurs, leading to the formation of cracks within the body. Once these cracks form, they expand and eventually lead to cracking. Convective Heat Transfer Formula During the drying process, heat is primarily transferred through convection between the air and the surface of the ceramic body.

According to Newton's law of cooling, convective heat transfer can be expressed as:

[ q = h \cdot A \cdot (T_s - T_\infty) ]

where:

• ( q ) is the heat transfer rate (W)

• ( h ) is the convective heat transfer coefficient (W/m²·K)

• ( A ) is the heat transfer area (m²)

• ( T_s ) is the surface temperature of the ceramic body (K)

• ( T_\infty ) is the ambient air temperature

Baesd on the formualtion, we could find the methods to avoid bricks drying cracks:

1. Control Drying Speed: Gradually reduce humidity and increase temperature to ensure uniform evaporation of moisture. Use a low-temperature, low-wind-speed drying environment to prevent rapid surface water loss.

2. Improve Body Design: Increase uniformity of wall thickness, reduce complex shapes and sharp corners to lower stress concentration.

3. Add Plasticizers: Incorporate appropriate amounts of plasticizers, such as methylcellulose, into the clay to enhance the toughness of the body and reduce the risk of cracking.

4. Segmental Drying: Use a multi-stage drying method, starting with preliminary drying followed by gradual temperature increases, allowing moisture to be expelled gradually and avoiding abrupt changes.

5. Monitor the Drying Process: Continuously monitor the temperature and humidity changes of the ceramic body, and adjust the drying parameters in real time to ensure a smooth drying process.

Through the above measures, cracking issues during the ceramic body drying process can be effectively avoided, ensuring product quality.