Zirconia-toughened alumina (ZTA) shows a considerable improvement in strength and more importantly toughness. As a result, these ceramics can be used in areas of extreme mechanical abrasion and thermal shock.
Fully stabilised zirconia (FSZ) produces a high-density ceramic on sintering. The grain size is relatively large at 10-40µm (microns) and the ceramics are often translucent in appearance. Recent optimisation of zirconia powders have resulted in a readily sinterable high-purity product.
Material Properties
Please note that the information set forth herein is offered for comparison only, and is not to be construed as absolute engineering data or constituting a warranty or representation for which we assume legal responsibility.
Property | Unit | Test | Zirconia Toughened Alumina |
---|---|---|---|
Density | g.cc-1 | ASTM C20 | 4.0 |
Colour | ** | ** | WHITE |
Elastic Modulus | GPa | ASTM C848 | 360 |
Flexural Strength | MPa | ASTM F417 | 450 |
Compressive Strength | MPa | ASTM C773 | 2900 |
Fracture Toughness Range | MPa | NOTCHED BEAM | 5-6 |
Hardness | GPa | ROCKWELL 45N | 85 |
Thermal Conductivity | W/mK | ASTM C20 | 27 |
CTE 25-1000 | 10(-6)/0C/ | ASTM C372 | 8.2 |
Thermal Shock | delta Tc | NOTE3 | 300 |
Dielectric Strength | ac-kv/mm (6.25mm) | ASTM D116 | 9.0 |
Dielectric Loss | 250C@1MHz | ASTM D2520 | 0.0005 |
Volume Resistivity | 1000C ohm-cm | ASTM D1829 | 10^6 |
- DATA MEASUREMENTS – All data measurements are typical and made at room temperature unless otherwise noted.
- THERMAL SHOCK RESISTANCE – Tests are run by quenching samples into water from various elevated temperatures. The change in temperature where a sharp decrease in flexural strength is observed is listed as ‘delta Tc’.
- CHEMICAL RESISTANCE – Although all alumina and zirconia ceramics are highly resistant to chemical attack, it is recommended that specific applications are discussed with Almath Crucibles to ensure optimum ceramic selection.