Why does the ceramic basin crack naturally

Ceramics have thousands of advantages. Dishes or soups with high hardness, high strength, no pollution, high temperature resistance and high heat will not produce harmful substances or gases, etc. However, unfortunately, they can not escape the "shackle" of "brittleness". The characteristic is that they are either intact or broken when encountering external forces. Each ceramic material (even if the composition is the same and the internal microstructure is different, it is also a "different material") has an ultimate stress that can be borne. If the stress is below the limit, the material is intact, but once it exceeds the limit, it will not deform but break directly.

Your plate is "broken".

Don't you cherish it? I'm sure I didn't fall. However, there are two kinds of stress on materials: external mechanical stress, which is caused by knocking or falling; There is also a kind of "thermal stress". When the temperature of the material changes, the internal thermal stress will be generated. The greater the temperature gradient, the greater the thermal stress (the temperature difference between the two surfaces of the plate or bowl is also a temperature gradient, which will also generate thermal stress).

Did your plate crack unknowingly?

With such care, there must be no external forces such as large falls, that is, the mechanical stress is very small; Although non material professionals may not know much about "thermal stress", they should know the common sense that quench and heat will break glass. Therefore, your plate should also avoid throwing it directly into cold water from high temperature.

However, small mechanical stress is difficult to avoid. For example, when it is placed on the hard dishwashing pool, it makes a crisp sound when it is inadvertently forced; Small thermal stress is also difficult to avoid. For example, the existence of temperature gradient will naturally cause thermal stress at the moment of holding hot dishes or soup, or when heating in a microwave oven.

Although the stress during normal use is very small, the plate will not be damaged as a rule.

But it's a pity that although your plate looks perfect, it's just because there is a layer of greasy "glaze" outside the plate, which deceives your eyes. In fact, the ceramic materials wrapped in the glaze layer, even the glaze layer itself, are uneven inside the material. This "unevenness" will first bring defects and second lead to different thermal expansion when heated.

The stress bearing capacity of the defective part will be abnormally low; Different thermal expansion will cause greater thermal stress under the same temperature gradient, so the position with the greatest difference in thermal expansion is also the weakest.