ZTA-20
Grade · default condition
ZTA-20 = alumina with ~20 wt% Y-stabilized ZrO₂
Use the ~20 wt% Y-stabilised ZrO2 standard grade as the default for seal rings, ball cores and wire-drawing dies; it balances strength, toughness and hardness better than the 10 or 30 % versions.
Values for the ZTA-20 condition
Other ZTA tempers and conditions
ZTA is listed in 5 conditions; see the grade overview at ZTA.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
coarse-grain wear-liner / grinding-media grade | Pick the coarse-grain industrial grade containing a small glass phase when cost per unit of wear resistance rules, for chute liners, cyclones and ball-mill media; service is limited to 1200 °C. | — | — | — | 1,350 HV | 20 W/m·K |
Alumina with 25–30 wt% ZrO₂ | Choose 25–30 wt% ZrO2 when impact loading and thermal shock dominate, as in extrusion and drawing dies; toughness rises while hardness and conductivity fall to 18 W/m·K. | — | — | — | 1,400 HV | 18 W/m·K |
ZTA-20DefaultThis page Alumina with ~20 wt% Y-stabilized ZrO₂ | Use the ~20 wt% Y-stabilised ZrO2 standard grade as the default for seal rings, ball cores and wire-drawing dies; it balances strength, toughness and hardness better than the 10 or 30 % versions. | — | — | — | 1,500 HV | 24 W/m·K |
Alumina with ~10 wt% ZrO₂ | Pick the ~10 wt% ZrO2 alumina for the hardest, most thermally conductive (26 W/m·K) and most economical option in wear liners, grinding media and general structural parts up to 1550 °C. | — | — | — | 1,600 HV | 26 W/m·K |
Hot isostatically pressed fine-grain ZTA | Specify hot isostatic pressing for near-zero porosity and fine grain when strength and polishability are critical — sealing faces, medical and high-stress precision parts — at lower machinability. | — | — | — | 1,600 HV | — |
What is ZTA-20?
ZTA-20 is ZTA in the ZTA-20 grade — use the ~20 wt% Y-stabilised ZrO2 standard grade as the default for seal rings, ball cores and wire-drawing dies; it balances strength, toughness and hardness better than the 10 or 30 % versions. ZTA-20 has a tensile strength of 260 MPa (37.7 ksi), stronger than 65% of ceramic grades. The elastic modulus is 350 GPa (50.8 Msi). ZTA-20 has a density of 4.15 g/cm³ (0.15 lb/in³), lighter than 57% of ceramic grades. It melts at 1,870°C (3,398 °F).
Advantages
- Good corrosion resistance — 92/100, better than 88% of ceramic grades
- High service temperature — 1,500°C (2,732 °F), better than 80% of ceramic grades
- Polishes to a fine finish — 90/100, better than 78% of ceramic grades
ZTA-20 properties
Typical room-temperature values for ZTA-20; 10 are specific to this condition. Other listed values are ZTA reference data and may not represent this condition. Bars are the position among ceramic grades.
Physical3
ZTA-20 has a density of 4.15 g/cm³ (0.15 lb/in³), lighter than 57% of ceramic grades. It melts at 1,870°C (3,398 °F).
Mechanical11
ZTA-20 has a tensile strength of 260 MPa (37.7 ksi), stronger than 65% of ceramic grades. The elastic modulus is 350 GPa (50.8 Msi).
Thermal5
ZTA-20 is rated for continuous service to 1,500°C (2,732 °F). It conducts heat at 24 W/m·K (13.9 BTU/hr·ft·°F), better than 53% of ceramic grades. Thermal expansion is 8.3 µm/m·K (4.61 µin/in·°F).
Electrical5
ZTA-20 is an electrical insulator with a dielectric strength of 12 kV/mm (304.8 V/mil) and a resistivity of 1×10¹² Ω·m.
Chemical & Environmental2
Corrosion resistance is excellent (92/100), better than 88% of ceramic grades.
Sustainability4
Producing a kilogram of ZTA-20 takes about 80 MJ of energy and emits 7 kg of CO₂ — less than 67% of ceramic grades. Typical recycled content is 1%.
Manufacturability3
ZTA-20's machinability is not recommended (5/100, worse than 59% of ceramic grades).
Common Calculations4
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with ZTA-20
Is ZTA easy to machine?
Green bodies can be turned, milled and drilled with an allowance of 15–20 % sintering shrinkage. After sintering, use diamond wheel grinding, honing, laser or ultrasonic machining only.
Can ZTA be welded?
Not weldable; join to metals by active-metal brazing (Ti or Ag-Cu), Mo-Mn metallizing followed by brazing, or mechanical and adhesive assembly.
Can ZTA be formed, bent or molded?
Dry pressing, isostatic pressing, slip casting or ceramic injection moulding, followed by air sintering at 1500–1680 °C; high-end parts are hot isostatically pressed for full density.
What surface finishes work on ZTA?
Diamond lapping and polishing reach Ra ≤ 0.05 µm. Parts can be laser marked, and all edges should be chamfered to remove chipping initiation sites.
ZTA chemical composition (wt %)
Limits by weight percent from the governing specification, written the way the spec states them — a single maximum for impurities, a range for alloying elements, and the base element as balance. Nominal is the typical mid-range value.
| Element | Spec limit (wt %) | Nominal |
|---|---|---|
| ZrO2Tetragonal, usually Y2O3-stabilized; some grades unstabilized ZrO2 | 15 – 25 | 20 |
| Y2O3ZrO2 stabilizer (about 2-3 mol% of the ZrO2) | 0.2 – 1.5 | 0.6 |
| MgOgrain growth inhibitor / sintering aid | 0 – 0.5 | 0.2 |
| SiO2+CaOLiquid-phase sintering aid; lower in precision grades | 0 – 1 | 0.3 |
| Al2O3matrix phase, typically 75-85 wt% | balance | — |
ZTA-20 — frequently asked
What is ZTA-20 used for?
ZTA-20 is typically used for cutting tool inserts, ballistic armor, wear plates, pump/valve components and bearing balls. In short: tougher than plain alumina; serves to 1500 °C; hard-wearing armor ceramic.
What is the tensile strength of ZTA-20?
ZTA-20 has a typical tensile strength of 260 MPa (37.7 ksi) — stronger than 65% of ceramic grades. Strength varies by condition: see the 5 listed tempers.
Is ZTA-20 easy to machine?
Not especially — machinability is rated not recommended (5/100, worse than 59% of ceramic grades). Green bodies can be turned, milled and drilled with an allowance of 15–20 % sintering shrinkage. After sintering, use diamond wheel grinding, honing, laser or ultrasonic machining only.
Can ZTA-20 be welded?
Not weldable; join to metals by active-metal brazing (Ti or Ag-Cu), Mo-Mn metallizing followed by brazing, or mechanical and adhesive assembly.
What surface finishes work on ZTA-20?
Diamond lapping and polishing reach Ra ≤ 0.05 µm. Parts can be laser marked, and all edges should be chamfered to remove chipping initiation sites.
Can ZTA-20 be formed, bent or molded?
Dry pressing, isostatic pressing, slip casting or ceramic injection moulding, followed by air sintering at 1500–1680 °C; high-end parts are hot isostatically pressed for full density.
What is the maximum service temperature of ZTA-20?
ZTA-20 is rated for continuous use to about 1,500°C (2,732 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Sources
- ASM Engineered Materials Handbook Vol.4: Ceramics and Glasses — ASM International (1991)
- Zirconia Toughened Alumina (ZTA) technical ceramic datasheets — CoorsTek / CeramTec / Kyocera (2023)
- ISO 23146 Fine ceramics — Fracture toughness (SEVNB) — ISO (2016)
Property data is compiled from published supplier and standards handbooks and normalised for comparison. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.