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Yttria-stabilized zirconium oxide (YSZ) ceramics are used in a number of industries – from intricate components and functions used in…

Yttria-stabilized zirconium oxide (YSZ) ceramics are used in a number of industries – from intricate components and functions used in jewelry and watchmaking to extremely hard, durable structural ceramics used in extreme environments.

Mechanical and Optical Features are both important in watchmaking and jewelry to ensure a functional and desirable product is made.

Why Zirconia?

Stabilized zirconia has unique mechanical, physicochemical and electrical properties that make it an exceptional ceramic material of great interest to a wide range of industries and applications.

Pure zirconia is present as a natural mineral called bath particle and can be observed in one of three states depending on the temperature 1

(Figure 1).

  1. At room temperature there is zirconium oxide in its monoclinic phase
  2. At temperatures above 175 ° C, it is transformed into a tetragonal phase. This conversion corresponds to modified properties that offer exceptional durability, excellent durability and high component and flexural strength. Because of these advantageous properties, the tetragon phase has many applications and is often used for structural ceramics in physically demanding applications.
  3. Zirconia is converted to its cubic state if the temperature rises above 2370 ° C.

Figure 1. Zirconium Phase Solid Transformations. As the temperature increases, zirconium oxide is converted from monoclinical (a) to tetragonal (b) to cubic (c) 2 .

Through a doping process, the highly sought after tetragonal state of zirconia can be preserved. This requires that oxides be added to the crystalline structure of zirconium oxide. Various oxides can be used to stabilize the higher temperature phases including ceria (CeO 2 ), calcia (CaO) and Magnesia (MgO), but yttria (Y 2 ] 3 ) is usually used because it has high solubility in the zirconium oxide grid 3 .

Some of the Zr 4+ ions are substituted in the crystal grid for the slightly larger Y 3 + ions to form yttrium stabilized zirconia (YSZ)


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