ceramic structural parts
1. The first is creep.
At high temperature, when the structure of alumina ceramics
is subjected to external force, due to the increase of time, plastic deformation will occur continuously and slowly, so we can call it creep . When the aluminum oxide ceramic structure creeps, whether it is related to stress or temperature, when the stress increases, or the temperature continues to rise, the creep rate will continue to increase.
2. Graphitization and spheroidization.
Under the action of high temperature, the cementite contained in the alumina ceramic structure will gather or migrate due to the acquisition of greater energy, and transform into coarse crystal grains. Cementite is mixed in ferrite, and cementite will gradually transform from flake to spherical, which we can call spheroidization. Because graphite is very low in strength, and mainly in the form of flakes, the strength of the material is greatly reduced, and the brittleness will increase accordingly, so it can be called graphitization.
3. Thermal fatigue performance.
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 be due to the effect of thermal stress, and there will be continuous expansion and small cracks, which will eventually appear serious. The rupture phenomenon. Therefore, when working under fluctuating temperature conditions, the fatigue performance of its structural parts should be considered.