When we see a ceramic cup, the first thing that attracts people's attention is not so much its shape, style or blank as the glaze covering the surface of the ceramic cup. If the surface of the ceramic cup is not glazed, I'm afraid it will lose its charm no matter how beautiful and new it is. Although we say that ceramics is the art of fire, and various changes have taken place under the action of fire, it is mainly the change of glaze in fire.
1. Glaze is made of rock or soil, just like blank. It is different from blank, but it is easier to melt in fire. When the power of fire in the kiln makes the green body semi molten, the raw material of glaze will completely melt into liquid state. After cooling, the liquid solidifies into a kind of glass, which is glaze.
2. Once the surface of ceramic cup is coated with glaze, it is very different from glass. When the glaze melts, it interacts with the green body of the product to form an intermediate layer, which gradually changes the glassy outside of the sintered green body. Although the thickness of glaze layer is usually only 1 ~ 3% of the thickness of green body, it will strongly change the thermal stability, dielectric strength, chemical stability and many other properties of products.