ZrO2

Zirconia ceramics are white, ceramic materials primarily composed of ZrO₂. As one of the most important oxide structural ceramics second only to alumina ceramics, zirconia ceramics exhibit high flexural strength and fracture toughness, along with strong corrosion resistance. Their properties—including a high melting point, high electrical resistivity, high refractive index, and low thermal expansion coefficient—make them essential as refractory materials, ceramic insulators, and ceramic opacifiers. Additionally, zirconia serves as a key raw material in the production of synthetic diamonds.

Material Characteristics

Under normal pressure, pure ZrO2 exists in three crystalline forms: monoclinic zirconia (m-ZrO2), tetragonal zirconia (t-ZrO2), and cubic zirconia (c-ZrO2). Typically, different types of stabilizers are added to produce various types of zirconia ceramics, such as partially stabilized zirconia (PSZ). When the stabilizers are CaO, MgO, or Y2O3, they are denoted as Ca-PSZ, Mg-PSZ, and Y-PSZ, respectively. Zirconia ceramics composed of metastable t-ZrO2 are called tetragonal zirconia polycrystal ceramics (TZP). If the stabilizers added are Y2O3 or CeO2, they are referred to as Y-TZP and Ce-TZP, respectively.

Material Applications

Structural Ceramics

In the field of structural ceramics, zirconia ceramics are widely used due to their high toughness, high flexural strength, high wear resistance, excellent thermal insulation properties, and a thermal expansion coefficient close to that of steel. Key applications include:

Functional Ceramics

Due to its excellent high-temperature resistance, zirconia is used in induction heating tubes, refractory materials, and heating elements. Additionally, zirconia ceramics exhibit sensitive electrical properties, making them suitable for applications such as:

Oxygen sensors
Solid Oxide Fuel Cells (SOFC)
High-temperature heating elements

ZrO₂ has a high refractive index (N-21^22). By adding coloring agents (such as V₂O₅, MoO₃, Fe₂O₃, etc.) to ultra-fine zirconia powder, it can be transformed into vibrant, translucent polycrystalline ZrO₂ materials that shimmer like natural gemstones, making them ideal for decorative items.

Furthermore, zirconia is increasingly being applied in:

Thermal barrier coatings
Catalyst supports
Medical and healthcare products
Refractory materials
Textile industry

This versatile material continues to expand its role across various high-tech and industrial fields.

Material Data

Properties		Units	Zirconia(ZrO₂)
			ZrO_{2_} Al₂O₃	Y₂O₃-ZrO₂ _3Y-TZP	Y₂O₃-ZrO₂ _8Y-PSZ	Mgo-ZrO₂
			ZrO_{2_} Al₂O₃	Y₂O₃-ZrO₂ _3Y-TZP	Y₂O₃-ZrO₂ _8Y-PSZ	Mgo-ZrO₂
Mechanical	Density	g/cm³	4.05	>6.0	5.7	5.6
	Color	—	White	Ivory / White	Ivory	Yellow/ Ivory
	Water Absorption	%	0	0	0	0
	Hardness	Gpa	16	12.7	6.4	12
	Flexural Strength (20°C)	Mpa	400	900	280	650
	Compressive Strength (20°C)	Mpa	2500	2500	1780	1800
Thermal	Thermal Conductivity (20°C)	W/m°k	20	2	2.5	2
	Thermal Shock Resistance (20°C)	∆T(°C)	300	250	500	375
	Maximum Use Temperature	°C	1600	1000	2400	1000
Electrical	Volume Resistivity (20°C)	Ω-cm	10¹²	10⁹	10⁸	10¹⁰