气相：陶瓷根据气孔率分为致密陶瓷、无开孔陶瓷和多孔陶瓷。除多孔陶瓷外，

Gas phase: Ceramics are classified into dense ceramics, non-porous ceramics and porous ceramics according to porosity. In addition to porous ceramics, porosity is detrimental to the performance of ceramics. It reduces the strength of ceramics and is often the source of cracks, so the porosity should be reduced as much as possible. The porosity of general ceramics is 5% to 10%; special ceramics are below 5%; cermets are required to be less than 0.5%.

Gas phase: Ceramics are divided into dense ceramics, non-perforated ceramics and porous ceramics according to the perforation rate. In addition to porous ceramics, pores are not conducive to the performance of ceramics, it reduces the strength of ceramics, often the root cause of cracks, so should be as far as possible to reduce the rate of pores. The perforation rate of ordinary ceramics is 5% to 10%, specialty ceramics are below 5%, and metal ceramics require less than 0.5%.

Gas phase: ceramics can be divided into dense ceramics, non porous ceramics and porous ceramics according to porosity. In addition to porous ceramics, porosity is unfavorable to the properties of ceramics. It reduces the strength of ceramics and is often the source of cracks. Therefore, the porosity should be reduced as much as possible. The porosity of general ceramics is 5% ~ 10%; that of special ceramics is less than 5%; that of cermets is less than 0.5%.<br>