We have noticed that several characteristics of refractory:
1. refractory materials usually belong to the heterogeneous, different linear expansion coefficient between the phases is often different, it can cause stress and cause micro-cracks. At the same time, refractory (brick) from the firing temperature cools for stress but also a source of micro-cracks. In addition, during formation of stress can cause high stress and micro-cracks on the surface, but do not lead to the final break.
2. refractories usually ingredients multistage, coarse granule, granule and powder in a broad size range, thus there are many pore, pore tends to become the starting point of fracture.
3. refractory materials at the time of manufacture due to forming the remaining pore and cause micro-cracks cannot be cleared during firing and use.
4. refractory materials used in the process thermal stress due to thermal shock and mechanical stress will significantly exceed their mechanical strength.
