Alumina ceramics is a kind of ceramics with alumina as the core, which is characterized by super high hardness, light weight, high heat conduction, high brittleness and wear resistance. Because ceramics have both hardness and brittleness, they are difficult to machine. The common methods in the industry are grinding, cutting, laser heating, high-pressure abrasive water jet and ultrasonic machining. What is the change of alumina ceramic structure under high temperature?

1、 Creep
The structural parts of alumina ceramics will be affected by external forces at high temperature. With the increase of time, the plasticity will change continuously and slowly. This phenomenon can be called creep. When the structural parts of alumina ceramics creep, there is a great relationship between stress and temperature. In addition, when the stress increases or the temperature increases, the creep rate will also increase.
       2、 Graphitization and spheroidization

Because graphite is relatively low in strength and mainly presents in flakes, it will lead to a lot of reduction in strength of materials, and the brittleness will also increase, so we call it graphitization. At the same time, in the case of high temperature, there will be a lot of cementite in the structural parts of alumina ceramics. Because of the large energy obtained, there will be aggregation or migration, which will change into cementite with coarse grains, and it will be directly mixed in ferrite. The main thing is that the cementite will gradually change from flake to sphere, so we call it spheroidization.
       3、 Thermal fatigue properties
If the alumina ceramic structure is in the condition of alternating hot and cold for a long time, the error of the material itself will change due to the effect of thermal stress, and will gradually appear small cracks, which will eventually lead to serious cracking. Therefore, it is necessary to consider the thermal fatigue of alumina ceramic structure when the temperature fluctuates greatly.