Zirconia Toughened Alumina Disc for Seals and Wear Parts
ADCERAX supplies ZTA ceramic discs for seals, valve seats, wear pads and precision assemblies. ZTA combines alumina wear resistance with zirconia-enhanced toughness, helping reduce chipping, corrosion wear and metal galling in demanding equipment.
Discs can be tailored by OD, ID, thickness, flatness, surface finish, hole pattern, groove design, chamfer and operating conditions for stable fit and reliable service.
Catalog No.
AT-ZTA-P1001
Material
Al2O3 + ZrO2
Ra
<0.6μm
Dimensional Accuracy
standard OD/ID tolerance ±0.2mm, custom up to ±0.1mm
A ZTA ceramic disc is a flat zirconia toughened alumina component used where sealing, sliding or wear-contact surfaces need higher toughness than standard alumina. The alumina matrix provides hardness and wear resistance, while zirconia reinforcement improves fracture toughness and helps reduce edge chipping under vibration, pressure cycling or repeated assembly.
For industrial equipment, ZTA discs are commonly selected for mechanical seal faces, valve seats, wear plates, support discs and custom ceramic inserts where dimensional stability, corrosion resistance and controlled surface finish are important.
Why Choose ZTA Instead of Standard Alumina?
ZTA is usually selected when standard alumina provides enough hardness but not enough toughness for the working condition. In mechanical seals, valves and wear assemblies, edge chipping, local impact, dry start-up, vibration and repeated maintenance can shorten alumina service life. ZTA helps improve fracture resistance while keeping good wear resistance and corrosion stability.
Compared with metal discs, ZTA provides a hard non-metallic contact surface that helps reduce galling, abrasive wear and corrosion-related dimensional loss. Compared with silicon carbide, ZTA may be considered when the design needs improved toughness, easier replacement matching or a more balanced cost-performance option. Final selection should still be checked according to pressure, medium, counterface material and thermal condition.
ZTA Ceramic Disc Material Properties
Property
Unit
ZTA
Bulk Density
g/cm³
4.0-4.3
Flexural Strength
MPa
700
Fracture Toughness
MPa·m1/2
7
Dielectric Constant (20°C, 1MHz)
εr
9.2
Hardness
HRA
90
Volume Resistivity (20°C)
Ω·cm
1014
Young's Modulus
GPa
330
Coefficient of Thermal Expansion
x10-6/K
7.5-11.2
Compressive Strength
MPa
2300
Wear Rate
g/cm²
0.1
Thermal Conductivity (20°C)
W/m·K
1.3-2.7
Poisson's Ratio
0.25
Dielectric Strength
kV/mm
20
Maximum Temperature
°C
1700
Zirconia Toughened Alumina Disc Specifications
Type 1: Square ZTA Disc
Square ZTA Disc
Item No.
Length *Width（mm)
Thickness（mm)
AT-ZTA-P1001
150*100
5
AT-ZTA-P1002
250*100
10
AT-ZTA-P1003
300*200
10
Type 2: Round ZTA Disc
Round ZTA Disc
Item No.
Diameter（mm)
Thickness（mm)
AT-ZTA-P2001
50
5
AT-ZTA-P2002
50
8
AT-ZTA-P2003
100
5
AT-ZTA-P2004
100
10
AT-ZTA-P2005
150
10
ZTA Disc Packaging
Each ZTA disc is separated in plastic cavity trays or foam-lined partitions so that sealing faces do not contact each other.
Applications of ZTA Ceramic Discs
ZTA ceramic discs are used in industrial assemblies where flat ceramic contact surfaces must resist wear, corrosion, chipping and dimensional loss. The most suitable application should be reviewed according to load direction, medium, counterface material, surface finish and installation method.
Mechanical Seal Faces for Pumps and Mixers
ZTA discs can be used as stationary or rotating seal faces in pumps, mixers, agitators and selected compressor seal assemblies. They are suitable when standard alumina faces may chip during start-stop operation or when metallic faces suffer from corrosion, galling or abrasive wear.
Key review points include seal type, shaft speed, pressure, medium, solids content, lubrication condition, face flatness, surface roughness and counterface material.
Valve Seats and Flow-Control Discs
In industrial valves, ZTA ceramic discs can be used as valve seats, throttling plates or wear-resistant sealing inserts. Their hardness and toughness help maintain the sealing line when the valve handles abrasive slurry, particle-loaded liquid or corrosive process media.
ZTA discs can serve as wear pads, guide discs and support plates in process equipment, textile machinery, dosing systems and motion-control assemblies. They are useful when repeated sliding contact, vibration or misalignment may damage standard ceramic or metallic parts.
Key review points include contact speed, load direction, mating material, lubrication, impact risk, surface finish and allowable wear tolerance.
Custom Ceramic Inserts for Drawing-Based Assemblies
For OEM equipment, ZTA ceramic discs can be machined with holes, slots, grooves, recesses, chamfers or stepped profiles according to the drawing. This allows the disc to fit existing housings, replacement assemblies or new mechanical designs without changing the complete equipment structure.
Key review points include drawing geometry, tolerance stack-up, datum faces, mounting method, inspection method and packaging protection for lapped surfaces.
ZTA Ceramic Disc Usage Instructions
Correct installation, handling and cleaning help ZTA ceramic discs maintain stable sealing or wear performance. Because ceramic discs are hard and brittle compared with metals, the assembly should avoid point loading, edge impact and uncontrolled tightening.
Installation
1. Check the ceramic disc for chips, cracks, surface scratches or edge damage before assembly.
2. Confirm that the mating housing, gasket, O-ring or backing ring is clean and free from burrs.
3. Apply mounting force evenly and avoid direct point contact between the ceramic edge and metal seat.
Operation
1. Avoid dry running unless the seal or valve design has been reviewed for that condition.
2. Monitor leakage, vibration, torque or temperature during the first operating cycle after installation.
3. For abrasive slurry or particle-loaded media, confirm flushing and filtration conditions to reduce face scratching.
Cleaning
1. Use soft lint-free cloth, neutral detergent or a compatible solvent based on the working medium.
2. Do not clean lapped faces with steel brushes, hard abrasives or uncontrolled blasting.
3. If deposits remain, soak the disc in a suitable cleaning solution before wiping the surface.
Storage
1. Store ZTA discs in cavity trays, foam partitions or individual bags to prevent ceramic-to-ceramic contact.
2. Keep lapped faces separated and protected from dust, moisture and hard particles.
3. Maintain drawing number, batch number and material grade labels for repeat orders and replacement control.
Common Misuse Points and Practical Fixes
1. Over-tightening against a rigid seat
Issue: Excessive preload on a flat ZTA disc against a rigid metallic seat can cause micro-cracks at the edge.
Fix: Use specified torque values, introduce compliant gaskets or backing rings, and check surface flatness before assembly.
2. Thermal shock from rapid quenching
Issue: Moving a hot ZTA disc assembly directly into cold liquid can induce thermal stress and lead to cracking.
Fix: Follow controlled cooldown procedures; avoid sudden temperature changes beyond recommended rates stated in equipment instructions.
3. Contamination trapped between sealing faces
Issue: Hard particles trapped on the ZTA disc face can scratch the surface and accelerate wear.
Fix: Flush systems thoroughly during start-up and after maintenance; keep assemblies covered and clean before installation.
ZTA Ceramic Disc FAQ
What is a ZTA ceramic disc?
A ZTA ceramic disc is a zirconia toughened alumina ceramic component used as a flat sealing, wear or support surface in industrial equipment. It combines alumina hardness with improved toughness from zirconia reinforcement, making it suitable for seals, valves and wear-contact assemblies.
Is ZTA better than alumina for seal faces?
ZTA is often better than standard alumina when the seal face is exposed to vibration, pressure cycling, impact during assembly or abrasive media. Standard alumina is still suitable for many stable-duty applications, but ZTA can reduce edge chipping risk when toughness is more important.
Can a ZTA ceramic disc replace a silicon carbide disc?
A ZTA ceramic disc may replace silicon carbide in selected applications, but it should not be treated as a direct drop-in replacement without review. Pressure, temperature, counterface material, chemical medium, thermal expansion and surface finish should be checked before substitution.
What surface finish is needed for a ZTA seal disc?
The required surface finish depends on the seal design and leakage requirement. General contact surfaces may use ground finishes, while mechanical seal faces often require lapped surfaces with controlled flatness, parallelism and roughness.
Can ZTA ceramic discs be made with holes, grooves or slots?
Yes. ZTA ceramic discs can be machined with through holes, countersinks, slots, shallow grooves, recesses, chamfers or stepped profiles according to the drawing. The final design should consider ceramic machining limits, edge strength and mounting stress.
What information is needed to quote a custom ZTA ceramic disc?
A useful quotation request should include OD, ID, thickness, drawing, tolerance, surface finish, flatness, hole or groove design, edge chamfer, material grade, operating medium, temperature, pressure, counterface material and expected quantity.
ZTA ceramic discs are normally drawing-based parts; the disc geometry, sealing face quality and tolerances can be tailored to each pump, compressor or valve design.
1. Outer Diameter (OD) Options
Typical range: 10–160 mm; larger OD available for valve plates.
Tolerance: ±0.02–0.05 mm depending on size and machining route.
OD roundness control for sealing-grade discs.
2. Inner Diameter (ID) /Functional Holes
Single or multi-hole patterns, including through holes, countersinks, key slots, and radial ports.
ID tolerance similar to OD, with optional precision cylindrical grinding for fit-critical assemblies.
3. Thickness Range
Common: 2–20 mm; thin discs for compact seals, thick discs for throttling elements.
Optional step-thickness designs for hybrid sealing faces.
4. Face Configuration
Flat, one-sided lapped, double-lapped sealing faces, or machined functional surfaces.
Optional shallow grooves, spiral patterns, recesses, and pressure-balancing pockets for custom flow control.
5. Surface Finish
Ground / fine ground surfaces for general contact areas.
Sealing-grade faces lapped to Ra ≈ 0.2–0.4 μm; finer finish possible on request.
Optional matte or polished edge for easier installation.
6. Edge Design
Chamfered edges, radius edges, or protective land to reduce chipping during assembly.
Optional soft transition edges for high-cycle mechanical seals.
7. Material Grade (ZTA Composition)
Alumina/zirconia ratio optimized for toughness and wear resistance (industry-typical ZrO₂ content approx. 10–30%).
Microstructure options: fine-grain, high-density, or impact-toughened ZTA variants depending on use.
