Reasons and solutions for yellowing of zirconia ceramics after sintering

Generally, the surface of high-quality zirconia ceramics is white, yellow, or gray when impurities are contained, but it will turn yellow after sintering.

        Why does zirconia ceramic turn yellow after sintering:

1. Is the sagger or layered slab you use new? If it is new, you need to burn it several times before sintering the product;

2. Is the temperature in the high-temperature zone too high? Is the chimney of the furnace well ventilated;

3. Is the product stacked too much? Without burning in an oxidizing atmosphere, there are oxygen vacancies, and the product will have a color;

4. The raw material of zirconia ceramic contains impurities. Iron impurities will turn yellow in oxidation. If there is more yttrium doped, there will be color. It is recommended to open the furnace lid, the effect may be completely different;

5. The final issue may be the internal pollution of the furnace.

Treatment method for yellowing of zirconia ceramics:

        Use white vinegar and lemon peel. First, wipe off the dirt on the surface of the sanitary ware, and then wipe the surface of the sanitary ware with a soft cloth dipped in a little white vinegar or wipe with lemon peel, the sanitary ware will be as bright as new.

         The reason why the above zirconia ceramics turn yellow after sintering is introduced here. The sintered Y toughened zirconia ceramics are white at 1450°. The molecular weight of zirconia is 123.22, the theoretical density is 5.89g/cm3, and the melting point is 2715°C.