Recently, some people have raised the issue that zirconia ceramics will crack after sintering, so what is the truth? Below is the answer from Pintejin Ceramics.
The pure zirconia ceramics were sintered and cracked. The zirconia made by the grouting method was naturally air-dried for 3 days and then placed in a high-temperature furnace. The temperature was raised to 1450°C at 3°C/min and 5°C/min respectively, held for 4 hours, and cooled out of the furnace. Cracking occurs.
Due to the high hardness of stabilized zirconia, it is generally used in a steel ball mill for ductile ink, pickling after the ductile ink, and then neutralized with water and dried. Using the grouting method to form, use the above materials to configure neutral mud in the ceramic ball mill, material: ball: water: glue (gum arabic) = 1: 1.5: 0.6: 0.15. The raw material requires zirconia to be ultra-fine powder (smaller than 0.05um) with a purity of 99.5%. Zirconia Ceramic Ring Processing Sintering: Sintering at 1800–1840 degrees in a neutral or oxidizing atmosphere. The phase transition of zirconia has a large volume change, so as to absorb or release energy. You’d better find the univariate phase diagram of zirconia and look at the phase transition point, which may be the main reason for cracking. In addition, to solve the phase transition of zirconia, many of them are inhibited by doping. For example, YSZ or SSZ, which are often used in high-temperature fuel cells, are stabilized to room temperature by doping a certain phase. Generally, Y oxides or other materials are doped to inhibit the phase transformation of zirconia. If you do not add any inhibitors, cracking during sintering is inevitable.
Pintejin Ceramic Factory has always used high-quality zirconia ceramic raw materials for ceramic machining, so as to create a piece of assured ceramic products and deliver them to customers.