Zirconia ceramics deform during the sintering process, which may be due to the excessively wide particle size distribution of the powder; the unreasonable selection and addition of additives in the powder; and the inconsistent shrinkage of the ceramics.
The inconsistent shrinkage of ceramics is due to the following three reasons:
1. The furnace temperature is not uniform, and the ceramic body shrinks inconsistently;
2. The heating speed is fast, and the temperature conduction produces a gradient. The closer the ceramic body is to the surface, the faster the shrinkage, and the closer the center is, the slower the shrinkage;
3. There is a density gradient. During molding, the internal shrinkage ratio of the blank is inconsistent due to factors such as pressure and filler.
