How Does The Structure Of Alumina Ceramics Change At High Temperature?

1. The first is creep. When the structural parts of alumina ceramics are subjected to external forces at high temperatures, they will continuously and slowly undergo plastic deformation due to the increase of time, so we can call them creep. . When the structural parts of alumina ceramics creep, there is a relationship with both stress and temperature. When the stress increases or the temperature continues to rise, the creep speed will continue to increase.

2. Graphitization and spheroidization, under the action of high temperature, the cementite contained in the structural parts of alumina ceramics will aggregate or migrate due to the acquisition of large energy, and transform into coarse grains. Cementite is mixed in ferrite, and cementite will gradually transform from flake to spherical, we can call it spheroidization. Because the strength of graphite is very low, and it is mainly in the form of flakes, the strength of the material is greatly reduced, and the brittleness will also increase, so it can be called graphitization.

3. The performance of thermal fatigue, if the structural parts of alumina ceramics are alternated between cold and heat for a long time, the change in the internal temperature difference of the material will cause continuous expansion and tiny cracks due to the effect of thermal stress, and eventually serious rupture phenomenon. Therefore, when working under the condition of fluctuating temperature, the fatigue performance of its structural parts should be considered.