Among modern advanced ceramic materials, zirconium oxide (ZrO₂) is known as the “steel of ceramics” because of its outstanding strength, toughness and wear resistance. So what is zirconium oxide? What is zirconium dioxide? Is zirconium oxide a ceramic?
The answer is: Zirconia is a high-performance inorganic ceramic material widely used in industrial manufacturing, electronic substrates, medical devices and structural parts. As a leading manufacturer of advanced ceramics, ZhiHao Ceramics has been deeply engaged in the field of zirconia ceramics for many years, and has accumulated profound technical strength in material purity control, precision processing and high-temperature sintering technology.

Zirconium oxide (ZrO₂), also known as zirconium dioxide, is a white crystalline oxide with a high melting point (about 2700°C), high hardness and excellent chemical stability. It can exhibit three crystal structures at different temperatures:

• Monoclinic: room temperature stable, but less tough;

• Tetragonal: After doping with stabilizers (e.g. yttrium oxide Y₂O₃) it can exist at room temperature and has excellent strength and crack resistance;

• Cubic phase (Cubic): high-temperature stability, strong conductivity, mostly used in oxygen sensors and fuel cells.

In order to maintain structural stability, yttria-stabilized zirconia (Y-TZP), magnesium-stabilized zirconia (Mg-PSZ), etc., are commonly used in industrial production.
Therefore, zirconia is not only a ceramic, but also a cross between structural and functional ceramics, which can be used for a long time in extreme environments.

Zirconia ceramics differ in their properties depending on how their crystalline phase is stabilized. The main types include:

In addition, alumina-zirconia composite ceramics (ZTA) combines the high hardness of alumina with the high toughness of zirconia, and is one of the cost-effective material systems that ZhiHao Ceramics focuses on developing.

Zirconia ceramics typically have a hardness of 1200-1400 HV, significantly higher than stainless steel.
More importantly, it has a fracture toughness (KIC) of 8-10 MPa-m½, which makes it one of the few ceramics that combines “high hardness with high crack resistance”.
This explains why zirconia ceramics are able to replace metal parts in high stress environments such as bearings, valve spools, and cutting tools.

Zirconia ceramics have a melting point as high as 2700°C and a low thermal conductivity of only 1/10 that of metal, providing excellent thermal barrier characteristics.
Its sintering temperature is usually in the range of 1350-1550°C. Good ceramics achieve a denser microstructure through precise heat treatment and atmosphere control, thus enhancing thermal shock resistance and service life.

At room temperature, zirconia is an excellent electrical insulator, while at high temperatures, yttrium-doped zirconia exhibits oxygen-ion conductive properties and is widely used in solid oxide fuel cells (SOFCs) with oxygen sensors.

Zirconia shows excellent resistance to both acid and alkali media and remains stable in corrosive environments, making it an ideal structural ceramic material for chemical and energy equipment.

It can be seen that alumina ceramics are more suitable for high hardness occasions, while zirconia ceramics are more suitable for high toughness and impact resistance of structural parts.
Alumina-zirconia composite ceramics (ZTA) combine the best of both worlds, making them an ideal solution for industrial manufacturing.

Zirconia ceramics are extremely difficult to process due to their high hardness and brittleness. Zhihao Ceramics realizes high precision manufacturing of complex structural parts by virtue of precision grinding, CNC molding and high temperature sintering technologies.

Core processing capabilities include:

• Precision grinding and polishing: surface roughness Ra up to 0.02μm;

• CNC microfabrication: small holes, thin sheets and shaped part structures can be realized;

• High-temperature sintering and hot isostatic pressing (HIP) technology: ensures ceramic density ≥99.9%, significantly improving mechanical properties.

Zhihao Ceramics realizes the whole process quality control from powder to parts in zirconia ceramics processing, and is a representative brand among professional zirconia ceramics manufacturers.

The density of zirconia ceramics is an important indicator to evaluate its performance. Typically, the theoretical density of yttria-stabilized zirconia (Y-TZP) is 6.05 g/cm³, while ZhiHao ceramics can achieve a sintered density of ≥6.0 g/cm³ (relative density of 99.9% or more) by optimizing the particle size of the powder and the control of the sintering atmosphere.
The high density structure means lower porosity and better mechanical properties, especially in terms of wear resistance, flexural strength and lifetime stability.

In the international testing standards, to good ceramics strict implementation:

• GB/T 6569-2006: Test methods for density and porosity of ceramic materials

• ASTM C1327: Standard for Microhardness Measurement

• ISO 14704: Specification for the determination of fracture toughness of ceramics

In addition, the company has microstructure analysis, XRD crystal phase testing and surface roughness testing capabilities, and can provide customers with a full set of material properties test report.
This not only guarantees the high consistency of zirconia ceramics, but also gives purchasers greater peace of mind in quality tracing and application verification.

With the global demand for high-performance and environmentally friendly materials rising, zirconia ceramics are ushering in a new technological turning point. The future development direction is mainly reflected in the following aspects:

1. Lightweight and Composite Trends

   • Composite zirconia with silicon carbide, alumina, and aluminum nitride to improve toughness and reduce costs;

   • Promote the application of alumina-zirconia composite ceramics (ZTA) in semiconductor devices and high-temperature electronic packaging.

2. Green and low-carbon manufacturing

   • Zhihao Ceramics actively promotes low-energy sintering processes (such as microwave sintering and rapid hot pressing technology) to reduce energy consumption and carbon emissions;

   • Introducing recyclable ceramic powders and environmentally friendly processing fluids to realize the greening of the entire production process.

3. Intelligent Inspection and Digital Production

   • AI algorithms monitor sintering curves and densification changes to improve consistency and batch qualification rates;

   • Create a digital ceramic manufacturing system to realize the full closed-loop control from material development to factory inspection.

To good ceramics is “innovation + environmental protection” as a double driving force, continue to lead the zirconia ceramics industry to high-end, intelligent and sustainable direction.

Zirconia ceramics are highly rated in the global market as the demand for high strength, high precision and extreme environment resistant materials continues to grow in the high-end manufacturing industry. The industry generally believes that it is the most promising new generation of structural ceramics after alumina.

1. Evaluation of engineering applications

• Zirconia ceramics have been evaluated as a “metal-substituting ceramic material” in the field of mechanical engineering;

• In the electronics industry, it is widely used for zirconia ceramic substrates and insulating sheets because of its low dielectric loss and excellent insulating properties;

2. Procurement and client feedback
Feedback from customers in Europe, America and Asia shows that the use of ZhiHao ceramic zirconia material generally extends the service life of the parts by 30%-50%, and maintenance costs are significantly reduced.
Especially in the field of high-temperature valve spools, bearing balls and nozzles, ZhiHao ceramic products have won the trust of long-term cooperative customers for their stable density, finish and high consistency.

3. Industry outlook
Zirconia ceramics are not only highly regarded in the industrial field, but are also recognized as a key support material for future new energy devices, semiconductor packaging and precision sensors.
With technological innovation and international standard manufacturing capability, Zhihao Ceramics is promoting zirconia ceramics from “material application” to “system solution”.

Zirconia ceramics, as a new generation of high-performance engineering materials, are widely entering the fields of high-end manufacturing, medical care, bio-engineering, electronics and energy.
With the advancement of processing technology and composite material technology, zirconia ceramics will show irreplaceable performance advantages in more demanding environments.
ZhiHao Ceramics will continue to focus on zirconia material innovation and industrialization, to provide customers around the world with more reliable and more precise advanced ceramic solutions.