High-temperature refractory ceramic material 3YSZ, or what we can call tetragonal zirconia polycrystal (TZP), is made of zirconium oxide that has been stabilized with 3% mol yttrium oxide.

These zirconia grades have the smallest grains and the greatest hardness at room temperature since they are almost all tetragonal. And its tiny (sub-micron) grain size makes it possible to achieve outstanding surface finishes and maintain a sharp edge.

Zirconia is frequently used as a stabilizer with either MgO, CaO, or Yttria to promote transition toughening. Instead of the first discharge producing a totally tetragonal crystal structure, this creates a partly cubic crystal structure that is metastable upon cooling. Tetragonal precipitates experience a stress-induced phase change close to an advancing crack tip upon impact. This process causes the structure to expand while absorbing a significant amount of energy, which accounts for this material's remarkable toughness. High temperatures also cause a significant amount of reforming, which has an adverse effect on strength and causes a 3-7% dimensional expansion. By adding the aforementioned mixes, the amount of tetragonal can be managed to strike a balance between toughness and strength loss.

At room temperature, tetragonal zirconia stabilized with 3 mol% Y2O3 (Y-TZP) displays the best performance in terms of toughness, bending strength. It also shows properties like ionic conductivity, low thermal conductivity, toughening after transformation, and shape memory effects. Tetragonal zirconia makes it possible to create ceramic components with outstanding corrosion resistance, superior wear resistance, and excellent surface finishing.

These kinds of features enable it to be widely used in areas like the biomedical field for hip transplant and dental reconstruction, and in the nuclear field as a thermal barrier layer in fuel rod claddings.