Description of ZTA Sealing Rings
Zirconia Toughened Alumina Ceramics (ZTA composite ceramic) exhibit a white colour, demonstrate corrosion resistance and retain stable chemical properties. Aluminium oxide contributes high hardness, while zirconium dioxide enhances fracture toughness. The combination of these materials yields a composite with high strength and fracture resistance, which permits a variety of applications.
ZTA ceramics show higher flexural strength and fracture toughness at ambient temperatures, thereby leading to increased wear resistance. The ratio of aluminium oxide to zirconium dioxide can be adjusted to meet the specific requirements of users. Pre-stressed zirconium dioxide reinforced aluminium oxide ceramics exhibit performance parameters that exceed those of 99% aluminium oxide ceramics, and they incur lower costs compared with pure zirconium dioxide ceramics.
This characteristic makes ZTA ceramics a practical alternative when aluminium oxide ceramics are not appropriate for a particular application, as they maintain the required mechanical properties at a reduced cost.
Specifications for ZTA Sealing Rings
|
Condition
|
Unit
|
ZTA Substrate
|
|
ZTA
|
|
Material
|
-
|
-
|
Al2O3/ZrO2
|
|
Colour
|
-
|
-
|
White
|
|
Packed Density
|
-
|
g/cm3
|
4
|
|
Surface Roughness Ra
|
-
|
µm
|
0.2
|
|
Reflectance
|
0.3-0.4 mmt
|
%
|
80
|
|
0.8-1.0 mmt
|
90
|
|
Mechanical
|
Flexural Strength
|
3-Point Method
|
MPa
|
700
|
|
Elastic Modulus
|
-
|
GPa
|
310
|
|
Vickers Hardness
|
-
|
GPa
|
15
|
|
Fracture Toughness
|
IF Method
|
MPa･m1/2
|
3.5
|
|
Thermal
|
Coefficient of Thermal Expansion
|
40-400°C
|
10-6/K
|
7.1
|
|
40-800°C
|
8
|
|
Thermal Conductivity
|
25°C
|
W/(m･K)
|
27
|
|
300°C
|
16
|
|
Specific Heat
|
25°C
|
J/(kg･K)
|
720
|
|
Electrical
|
Dielectric Constant
|
1MHz
|
-
|
10.2
|
|
Dielectric Loss Factor
|
1MHz
|
10-3
|
0.2
|
|
Volume Resistivity
|
25°C
|
Ω･cm
|
>1014
|
|
Breakdown Strength
|
DC
|
kV/mm
|
>15
|
Properties of Al2O3, ZTA, and YTZ
|
Item
|
Unit
|
Alumina (AL2O3)
|
Zirconium Dioxide (ZrO2)
|
|
AL2O3≥95
|
AL2O3≥99
|
AL2O3≥99.5
|
AL2O3≥99.8
|
ZTA
|
YTZ
|
|
Packed Density
|
g/cm3
|
3.7
|
3.80~3.85
|
3.85
|
3.9
|
3.8~4.6
|
6
|
|
Hardness (HRA≥)
|
|
86
|
88
|
88
|
88
|
86~88
|
88~90
|
|
Flexural Strength
|
MPa≥
|
300
|
350
|
400
|
400
|
172~450
|
900
|
|
Maximum Operating Temperature
|
°C
|
1500
|
1500
|
1500
|
1500
|
1400~1500
|
1500
|
|
Linear Coefficient of Expansion
|
×10-6/°C
|
7.5
|
8.2
|
8.2
|
8.2
|
|
|
|
Dielectric Constant (20°C, 1MHz)
|
|
9
|
9.2
|
9.2
|
9.2
|
|
|
|
Dielectric Loss (tanδ at 1MHz ×10-4)
|
|
3
|
2
|
2
|
2
|
|
|
|
Volume Resistivity (20°C)
|
Ω-cm
|
1013
|
1014
|
1014
|
1014
|
1013
|
1014
|
|
Breakdown Strength (DC, kV/mm ≥)
|
|
20
|
20
|
20
|
20
|
|
|
|
Acid Resistance (mg/cm2 ≤)
|
|
0.7
|
0.7
|
0.7
|
0.7
|
|
|
|
Alkali Resistance (mg/cm2 ≤)
|
|
0.2
|
0.1
|
0.1
|
0.1
|
|
|
|
Abrasion Resistance (g/cm2 ≤)
|
|
0.2
|
0.1
|
0.1
|
0.1
|
|
|
|
Compressive Strength
|
MPa≥
|
2500
|
2500
|
2500
|
2800
|
2300~2900
|
2500
|
|
Flexural Strength
|
MPa≥
|
200
|
350
|
350
|
350
|
|
|
|
Elastic Modulus
|
GPa
|
300
|
350
|
350
|
350
|
|
|
|
Poisson's Ratio
|
|
0.2
|
0.22
|
0.22
|
0.22
|
|
|
|
Thermal Conductivity Coefficient
|
W/m-K (20°C)
|
20
|
25
|
25
|
25
|
|
|
Applications of ZTA Sealing Rings
1. Pumps and Valves: ZTA ceramic sealing rings are employed in pumps and valves, particularly in the chemical and petrochemical industries, where they provide reliable sealing and resistance to both corrosion and wear.
2. Mechanical Seals: They are used in rotary seals for equipment such as compressors, mixers and agitators. Their performance in preventing leakage under operational conditions is well documented.
3. Aerospace and Defence: They are utilised in aerospace and defence applications where performance under high load is required. ZTA sealing rings exhibit resistance to thermal shocks and wear.
4. Oil and Gas: In the oil and gas sector, these sealing rings are applied in components for drilling equipment, pipelines and processing facilities. Their capacity to operate under high pressures, temperatures and chemically aggressive environments is confirmed.
5. Water Purification and Desalination: In water treatment and desalination plants, they are used to seal pumps and valves managing abrasive and corrosive media.
6. Automotive Industry: They are employed in automotive systems, including in engines and gearboxes, to improve efficiency and to reduce wear of moving parts.
7. Pharmaceutical and Food Processing: They are installed in facilities for pharmaceutical and food processing, where chemical inertness, hygiene and wear resistance are necessary for maintaining product purity and equipment longevity.
8. Power Generation: They are applied in power stations, including thermal, water and nuclear plants, to seal components that are exposed to high temperatures, pressures and corrosive environments.
9. Mining and Mineral Processing: They are utilised in mining and mineral processing plants for sealing applications requiring high wear resistance and the ability to withstand abrasive conditions.
10. Industrial Machinery: They are employed in a range of industrial machines and installations such as mixers, crushers and conveying systems, thereby contributing to maintained performance and reduced downtime.
Packaging of ZTA Sealing Rings
Our ZTA sealing rings are clearly labelled to ensure efficient identification and quality control. The products are packed in air cushioned bags to mitigate shock and are subsequently placed in wooden or cardboard boxes. Careful measures are taken to avoid damage during storage or transport.
Frequently Asked Questions (FAQ)
- Can ZTA ceramic sealing rings be customised for specific applications?
Yes, ZTA ceramic sealing rings can be customised in terms of composition, microstructure, dimensions, tolerances, surface finish and other properties to meet the specific requirements of various sealing applications.
- Are ZTA ceramic sealing rings suitable for high-pressure and high-temperature applications?
Yes, ZTA ceramic sealing rings possess the necessary mechanical and thermal properties to be applied in high-pressure and high-temperature environments, where conventional sealing materials may not perform as required.
- How are ZTA ceramic sealing rings handled and installed?
ZTA ceramic sealing rings should be handled carefully to avoid damage during transport, storage and installation. Proper cleaning and inspection procedures must be followed to ensure optimal sealing performance.
Converters & Calculators
