spore: profile
id: zirconia-ysz
spore_version: 0.2
family: oxide-ceramics
name: Yttria-stabilised zirconia
abbreviation: YSZ
role: structural ceramic
category: ceramics
type: oxides
summary: |
  Yttria-stabilised zirconia (YSZ) is zirconium dioxide with yttria (Y2O3) added to hold a tetragonal crystal form. The 3Y-TZP grade, with 3 mol% yttria, is the one the sources describe most fully: Morgan's datasheet gives a density of 6.07 g/cm3 and a flexural strength of 1000 MPa, and CoorsTek's sintered YTZP reaches 1240 MPa with a fracture toughness of 13 MPa√m. In hot water or steam the material ages, and a cited study reports about 12% strength loss.
best_for: 'Strong, tough wear parts and cutting edges that stay cool and dry (CoorsTek sintered YTZP: 1240 MPa and 13 MPa√m)'
weakest_at: 'Hot water or steam: about 12% strength loss after hydrothermal ageing in a cited study; thermal shock limits of 200 to 350 °C'
identity:
  formula: ZrO2 + 3 mol% Y2O3 (3Y-TZP); 8YSZ is ZrO2 + 8 mol% Y2O3
  cas: 1314-23-4
  source: pubchem-zro2
  where: 'PubChem CID 62395, zirconium dioxide: CAS 1314-23-4 is the number for the host oxide; the stabilised ceramic has no separate CAS in the sources read. Yttria content: 3 mol% (Morgan datasheet); 8YSZ is 8 mol% Y2O3 (Wikipedia, composition only).'
  designations:
    - system: Name
      code: 3Y-TZP
      source: morgan-3ytzp
      where: 'Title: Nilcra Zirconia 3Y-TZP Grade'
    - system: Name
      code: Y-TZP
      source: scielo-3ytzp
      where: 'Abstract: yttrium-stabilized zirconia ceramic (Y-TZP)'
    - system: Name
      code: YSZ
      source: wikipedia-ysz
      where: 'Lead section: yttria-stabilized zirconia (YSZ)'
    - system: Name
      code: 8YSZ
      source: wikipedia-ysz
      where: 'Lead section: 8YSZ, with 8 mol% Y2O3'
    - system: Name
      code: ZrO2
      source: morgan-3ytzp
      where: 'Description: 3 mol% (5.2 wt%) Y2O3 in ZrO2'
tags:
  environments: []
  stresses:
    - extreme-heat
  applications:
    - mechanisms
properties:
  - benchmark: density
    label: Density, CoorsTek YTZP (sintered)
    value: 6.02
    unit: g/cm3
    scope: material
    conditions:
      grade: CoorsTek YTZP, sintered column
      phase_and_yttria: not printed; the chart names it Y2O3 partially stabilised zirconia
      temperature: room temperature (chart note 1)
      test: ASTM C20
      unit_in_source: gm/cc
    method: Typical value from a manufacturer property chart
    status: ground
    source: coors-chart
    where: Properties table, Density row, YTZP (Sintered) column
  - benchmark: flexural_strength
    label: Flexural strength, CoorsTek YTZP (sintered)
    value: 1240
    unit: MPa
    scope: material
    conditions:
      grade: CoorsTek YTZP, sintered column
      phase_and_yttria: not printed; the chart names it Y2O3 partially stabilised zirconia
      temperature: 20 °C
      test: ASTM F417 (modulus of rupture, as printed)
      unit_in_source: MPa (psi x 10^3)
    method: Typical value from a manufacturer property chart
    status: ground
    note: The same chart lists 1720 MPa for the HIPed YTZP column; that is a different form and is not entered here.
    source: coors-chart
    where: Properties table, Flexural Strength (MOR) row, YTZP (Sintered) column
  - benchmark: elastic_modulus
    label: Elastic modulus, CoorsTek YTZP (sintered)
    value: 210
    unit: GPa
    scope: material
    conditions:
      grade: CoorsTek YTZP, sintered column
      phase_and_yttria: not printed; the chart names it Y2O3 partially stabilised zirconia
      temperature: 20 °C
      test: ASTM C848
      unit_in_source: GPa (psi x 10^6)
    method: Typical value from a manufacturer property chart
    status: ground
    source: coors-chart
    where: Properties table, Elastic Modulus row, YTZP (Sintered) column
  - benchmark: fracture_toughness
    label: Fracture toughness, CoorsTek YTZP (sintered)
    value: 13
    unit: MPa·√m
    scope: material
    conditions:
      grade: CoorsTek YTZP, sintered column
      phase_and_yttria: not printed; the chart names it Y2O3 partially stabilised zirconia
      temperature: room temperature (chart note 1)
      test: notched beam, K(Ic) as printed
      unit_in_source: Mpa m1/2
    method: Typical value from a manufacturer property chart
    status: ground
    source: coors-chart
    where: Properties table, Fracture Toughness row, YTZP (Sintered) column
  - benchmark: knoop_hardness
    label: Knoop hardness, CoorsTek YTZP (sintered)
    value: 12.7
    unit: GPa
    scope: material
    conditions:
      grade: CoorsTek YTZP, sintered column
      phase_and_yttria: not printed; the chart names it Y2O3 partially stabilised zirconia
      load: 1000 gm, as printed (KNOOP 1000 gm)
      test: Knoop indentation, as printed
      unit_in_source: GPa (kg/mm2)
    method: Typical value from a manufacturer property chart
    status: ground
    source: coors-chart
    where: Hardness, KNOOP 1000 gm row, YTZP (Sintered) column
  - benchmark: thermal_conductivity
    label: Thermal conductivity, CoorsTek YTZP (sintered)
    value: 2.2
    unit: W/(m·K)
    scope: material
    conditions:
      grade: CoorsTek YTZP, sintered column
      phase_and_yttria: not printed; the chart names it Y2O3 partially stabilised zirconia
      temperature: 20 °C
      test: ASTM C408
      unit_in_source: W/m K
    method: Typical value from a manufacturer property chart
    status: ground
    source: coors-chart
    where: Properties table, Thermal Conductivity row, YTZP (Sintered) column
  - benchmark: cte
    label: Thermal expansion, CoorsTek YTZP (sintered)
    value: 10.3
    unit: ppm/K
    scope: material
    conditions:
      grade: CoorsTek YTZP, sintered column
      phase_and_yttria: not printed; the chart names it Y2O3 partially stabilised zirconia
      temperature_range: 25 to 1000 °C
      test: ASTM C372
      unit_in_source: 1 x 10-6 per °C
    method: Mean coefficient from a manufacturer property chart
    status: ground
    source: coors-chart
    where: Properties table, Coefficient of Thermal Expansion row, YTZP (Sintered) column
  - benchmark: max_service_temp
    label: Maximum use temperature, CoorsTek YTZP (sintered)
    value: 1500
    unit: °C
    scope: material
    conditions:
      grade: CoorsTek YTZP, sintered column
      phase_and_yttria: not printed; the chart names it Y2O3 partially stabilised zirconia
      load: 'no load on the part (chart: NO-LOAD COND.)'
      test: chart rating
    method: Rating from a manufacturer property chart
    status: ground
    source: coors-chart
    where: Properties table, Maximum Use Temperature row, YTZP (Sintered) column
  - benchmark: thermal_shock_dt
    label: Thermal shock temperature difference, CoorsTek YTZP (sintered)
    value: 350
    unit: °C
    scope: material
    conditions:
      grade: CoorsTek YTZP, sintered column
      phase_and_yttria: not printed; the chart names it Y2O3 partially stabilised zirconia
      test: quenched into water from elevated temperature; DTc is the step where flexural strength falls sharply (chart note 3)
    method: Typical value from a manufacturer property chart
    status: ground
    source: coors-chart
    where: Thermal Shock Resistance row (note 3), YTZP (Sintered) column
  - benchmark: specific_heat
    label: Specific heat, CoorsTek YTZP (sintered)
    value: 400
    unit: J/(kg·K)
    scope: material
    conditions:
      grade: CoorsTek YTZP, sintered column
      phase_and_yttria: not printed; the chart names it Y2O3 partially stabilised zirconia
      temperature: 100 °C
      test: ASTM E1269
      unit_in_source: J/kg*K
    method: Typical value from a manufacturer property chart
    status: ground
    source: coors-chart
    where: Thermal Specific Heat row, YTZP (Sintered) column
  - benchmark: poissons_ratio
    label: Poisson ratio, CoorsTek YTZP (sintered)
    value: 0.23
    unit: '-'
    scope: material
    conditions:
      grade: CoorsTek YTZP, sintered column
      phase_and_yttria: not printed; the chart names it Y2O3 partially stabilised zirconia
      temperature: 20 °C
      test: ASTM C848
    method: Typical value from a manufacturer property chart
    status: ground
    source: coors-chart
    where: Poisson's Ratio row, YTZP (Sintered) column
  - benchmark: dielectric_strength
    label: Dielectric strength, CoorsTek YTZP (sintered)
    value: 9
    unit: kV/mm
    scope: material
    conditions:
      grade: CoorsTek YTZP, sintered column
      phase_and_yttria: not printed; the chart names it Y2O3 partially stabilised zirconia
      test: ASTM D116, ac
      sample: samples 0.25 inch thick (chart note 5)
      unit_in_source: ac-kV/mm (ac V/mil)
    method: Typical value from a manufacturer property chart
    status: ground
    source: coors-chart
    where: Dielectric Strength row, YTZP (Sintered) column (printed as 9.0)
  - benchmark: dielectric_constant
    label: Dielectric constant, CoorsTek YTZP (sintered)
    value: 29
    unit: '-'
    scope: material
    conditions:
      grade: CoorsTek YTZP, sintered column
      phase_and_yttria: not printed; the chart names it Y2O3 partially stabilised zirconia
      frequency: 1 MHz
      temperature: 25 °C
      test: ASTM D150
    method: Typical value from a manufacturer property chart
    status: ground
    source: coors-chart
    where: Dielectric Constant row, YTZP (Sintered) column
  - benchmark: dissipation_factor
    label: Dielectric loss (tan delta), CoorsTek YTZP (sintered)
    value: 0.001
    unit: '-'
    scope: material
    conditions:
      grade: CoorsTek YTZP, sintered column
      phase_and_yttria: not printed; the chart names it Y2O3 partially stabilised zirconia
      frequency: 1 MHz
      temperature: 25 °C
      test: ASTM D150
    method: Typical value from a manufacturer property chart
    status: ground
    source: coors-chart
    where: Dielectric Loss (tan delta) row, YTZP (Sintered) column
  - benchmark: density
    label: Density, Morgan Nilcra 3Y-TZP grade
    value: 6.07
    unit: g/cm3
    scope: material
    conditions:
      grade: Nilcra Zirconia 3Y-TZP Grade (Morgan datasheet)
      phase_and_yttria: 3 mol% (5.2 wt%) Y2O3 in ZrO2; tetragonal (Y-TZP)
      temperature: 20 °C
      test: not printed on the datasheet
    method: Typical value from a manufacturer datasheet; the datasheet says values are for test pieces, are not guaranteed and are for guidance only
    status: ground
    source: morgan-3ytzp
    where: Physical Properties, Density row
  - benchmark: flexural_strength
    label: Flexural strength, Morgan Nilcra 3Y-TZP grade
    value: 1000
    unit: MPa
    scope: material
    conditions:
      grade: Nilcra Zirconia 3Y-TZP Grade (Morgan datasheet)
      phase_and_yttria: 3 mol% (5.2 wt%) Y2O3 in ZrO2; tetragonal (Y-TZP)
      temperature: 20 °C
      test: not printed on the datasheet
    method: Typical value from a manufacturer datasheet; the datasheet says values are for test pieces, are not guaranteed and are for guidance only
    status: ground
    source: morgan-3ytzp
    where: Physical Properties, Flexural Strength row
  - benchmark: elastic_modulus
    label: Elastic modulus, Morgan Nilcra 3Y-TZP grade
    value: 205
    unit: GPa
    scope: material
    conditions:
      grade: Nilcra Zirconia 3Y-TZP Grade (Morgan datasheet)
      phase_and_yttria: 3 mol% (5.2 wt%) Y2O3 in ZrO2; tetragonal (Y-TZP)
      temperature: 20 °C
      test: not printed on the datasheet
    method: Typical value from a manufacturer datasheet; the datasheet says values are for test pieces, are not guaranteed and are for guidance only
    status: ground
    source: morgan-3ytzp
    where: Physical Properties, Modulus of Elasticity row
  - benchmark: poissons_ratio
    label: Poisson ratio, Morgan Nilcra 3Y-TZP grade
    value: 0.3
    unit: '-'
    scope: material
    conditions:
      grade: Nilcra Zirconia 3Y-TZP Grade (Morgan datasheet)
      phase_and_yttria: 3 mol% (5.2 wt%) Y2O3 in ZrO2; tetragonal (Y-TZP)
      temperature: 20 °C
      test: not printed on the datasheet
    method: Typical value from a manufacturer datasheet; the datasheet says values are for test pieces, are not guaranteed and are for guidance only
    status: ground
    source: morgan-3ytzp
    where: Physical Properties, Poisson's Ratio row
  - benchmark: vickers_hardness
    label: Vickers hardness HV0.3, Morgan Nilcra 3Y-TZP grade
    value: 1300
    unit: kg/mm2
    scope: material
    conditions:
      grade: Nilcra Zirconia 3Y-TZP Grade (Morgan datasheet)
      phase_and_yttria: 3 mol% (5.2 wt%) Y2O3 in ZrO2; tetragonal (Y-TZP)
      load: HV0.3 as printed
      temperature: 20 °C
      test: not printed on the datasheet
    method: Typical value from a manufacturer datasheet; the datasheet says values are for test pieces, are not guaranteed and are for guidance only
    status: ground
    source: morgan-3ytzp
    where: Physical Properties, Hardness HV0.3 row
  - benchmark: fracture_toughness
    label: Fracture toughness, Morgan Nilcra 3Y-TZP grade
    value: 10
    unit: MPa·√m
    scope: material
    conditions:
      grade: Nilcra Zirconia 3Y-TZP Grade (Morgan datasheet)
      phase_and_yttria: 3 mol% (5.2 wt%) Y2O3 in ZrO2; tetragonal (Y-TZP)
      temperature: 20 °C
      test: not printed on the datasheet
      unit_in_source: MPa√m
    method: Typical value from a manufacturer datasheet; the datasheet says values are for test pieces, are not guaranteed and are for guidance only
    status: ground
    source: morgan-3ytzp
    where: Physical Properties, Fracture Toughness row
  - benchmark: thermal_conductivity
    label: Thermal conductivity, Morgan Nilcra 3Y-TZP grade
    value: 3
    unit: W/(m·K)
    scope: material
    conditions:
      grade: Nilcra Zirconia 3Y-TZP Grade (Morgan datasheet)
      phase_and_yttria: 3 mol% (5.2 wt%) Y2O3 in ZrO2; tetragonal (Y-TZP)
      temperature: 20 °C
      test: not printed on the datasheet
      unit_in_source: W/m-K
    method: Typical value from a manufacturer datasheet; the datasheet says values are for test pieces, are not guaranteed and are for guidance only
    status: ground
    source: morgan-3ytzp
    where: Physical Properties, Thermal Conductivity row (printed as 3.0)
  - benchmark: cte
    label: Thermal expansion, Morgan Nilcra 3Y-TZP grade
    value: 9
    unit: ppm/K
    scope: material
    conditions:
      grade: Nilcra Zirconia 3Y-TZP Grade (Morgan datasheet)
      phase_and_yttria: 3 mol% (5.2 wt%) Y2O3 in ZrO2; tetragonal (Y-TZP)
      temperature_range: 25 to 400 °C
      test: not printed on the datasheet
      unit_in_source: x10-6/°C
    method: Coefficient from a manufacturer datasheet; the datasheet says values are for test pieces, are not guaranteed and are for guidance only
    status: ground
    source: morgan-3ytzp
    where: Physical Properties, Thermal Expansion Coefficient row
  - benchmark: max_service_temp
    label: Maximum use temperature, Morgan Nilcra 3Y-TZP grade
    value: 800
    unit: °C
    scope: material
    conditions:
      grade: Nilcra Zirconia 3Y-TZP Grade (Morgan datasheet)
      phase_and_yttria: 3 mol% (5.2 wt%) Y2O3 in ZrO2; tetragonal (Y-TZP)
      load: not printed on the datasheet
      test: not printed on the datasheet
    method: Rating from a manufacturer datasheet; the basis of the rating is not printed
    status: ground
    note: The CoorsTek YTZP chart gives 1500 °C with no load for a different material column; the two ratings are not compared as one scale.
    source: morgan-3ytzp
    where: Physical Properties, Maximum Use Temperature row
  - benchmark: thermal_shock_dt
    label: Thermal shock resistance, Morgan Nilcra 3Y-TZP grade
    value: 200
    unit: °C
    scope: material
    conditions:
      grade: Nilcra Zirconia 3Y-TZP Grade (Morgan datasheet)
      phase_and_yttria: 3 mol% (5.2 wt%) Y2O3 in ZrO2; tetragonal (Y-TZP)
      test: not printed on the datasheet
    method: Rating from a manufacturer datasheet; the datasheet says values are for test pieces, are not guaranteed and are for guidance only
    status: ground
    source: morgan-3ytzp
    where: Physical Properties, Thermal Shock Resistance row
  - benchmark: specific_heat
    label: Specific heat, Morgan Nilcra 3Y-TZP grade
    value: 0.5
    unit: J/g-K
    scope: material
    conditions:
      grade: Nilcra Zirconia 3Y-TZP Grade (Morgan datasheet)
      phase_and_yttria: 3 mol% (5.2 wt%) Y2O3 in ZrO2; tetragonal (Y-TZP)
      temperature: 20 °C
      test: not printed on the datasheet
    method: Typical value from a manufacturer datasheet; the datasheet says values are for test pieces, are not guaranteed and are for guidance only
    status: ground
    source: morgan-3ytzp
    where: Physical Properties, Specific Heat row
  - benchmark: flexural_strength
    label: Bending strength, 3Y-TZP sintered at 1500 °C (paper's own samples)
    value: 1192
    unit: MPa
    scope: material
    uncertainty: ±99 MPa as printed
    conditions:
      grade: 3Y-TZP sintered at 1500 °C for 2 h (the paper's own samples)
      phase_and_yttria: 3 mol.% Y2O3; tetragonal grains (paper)
      test: piston-on-three-balls bending (paper)
    method: Average bending strength measured in the paper by piston-on-three-balls testing
    status: ground
    source: scielo-3ytzp
    where: Abstract and Results, piston-on-three-balls bending strength
  - benchmark: elastic_modulus
    label: Elastic modulus, 3Y-TZP sintered at 1500 °C (paper's own samples)
    value: 195
    unit: GPa
    scope: material
    uncertainty: ±4 GPa as printed
    conditions:
      grade: 3Y-TZP sintered at 1500 °C for 2 h (the paper's own samples)
      phase_and_yttria: 3 mol.% Y2O3; tetragonal grains (paper)
      samples: 15 sintered samples (paper)
      test: impulse excitation technique (paper)
      densification: relative density above 99% (paper)
    method: Value measured in the paper on 15 sintered samples by impulse excitation
    status: ground
    source: scielo-3ytzp
    where: Results, elastic parameters paragraph (Table 1 cited)
  - benchmark: poissons_ratio
    label: Poisson ratio, 3Y-TZP sintered at 1500 °C (paper's own samples)
    value: 0.31
    unit: '-'
    scope: material
    conditions:
      grade: 3Y-TZP sintered at 1500 °C for 2 h (the paper's own samples)
      phase_and_yttria: 3 mol.% Y2O3; tetragonal grains (paper)
      test: impulse excitation technique (paper)
    method: Value measured in the paper by impulse excitation
    status: ground
    source: scielo-3ytzp
    where: Results, elastic parameters paragraph
  - benchmark: aged_cyclic_fatigue_limit
    label: Cyclic fatigue strength limit after autoclave ageing
    value: 550
    unit: MPa
    scope: material
    conditions:
      grade: 3Y-TZP ceramics of the cited study (the paper writes 3Y-YZP for that study)
      phase_and_yttria: 3Y as printed; tetragonal to monoclinic transformation during ageing (paper)
      ageing: autoclave at 134 °C for 5 h (the paper says this equals 30 years in the oral environment)
      test: cyclic fatigue of aged samples, as printed; the test set-up is not printed
    method: Value reported in the paragraph that cites reference 31; the paper does not say which study ran the fatigue test
    status: ground
    source: scielo-3ytzp
    where: Text paragraph that cites reference 31 (fatigue of aged samples)
corrosion:
  - environment: Hot water or steam (hydrothermal ageing; the paper's ageing test is an autoclave at 134 °C for 5 h)
    headline: A cited study reports about 12% flexural strength loss after hydrothermal ageing of 3Y-TZP.
    effect: The paragraph that cites reference 31 reports around 12% of flexural strength loss caused by a precocious tetragonal to monoclinic transformation after hydrothermal degradation, and a cyclic fatigue strength limit of 550 MPa for the degraded samples. The source gives no rating for this loss.
    rating: unknown
    conditions:
      material: 3Y-TZP ceramics of the cited study (the paper writes 3Y-YZP)
      phase_and_yttria: 3Y as printed; tetragonal to monoclinic transformation
      test: hydrothermal degradation; the paper's ageing test is an autoclave at 134 °C for 5 h (about 30 years in the oral environment, per the paper)
      result: about 12% flexural strength loss; 550 MPa cyclic fatigue limit for aged samples
    source: scielo-3ytzp
    where: Text paragraph that cites reference 31
risks:
  hazards:
    - text: 'PubChem reports zirconium dioxide as Not Classified under GHS: 1040 of 1116 company reports (93.2%) say it does not meet GHS hazard criteria, and only a small share of reports give any hazard information.'
      ghs: []
      source: pubchem-zro2
      where: Safety and Hazards, GHS Classification (CID 62395)
    - text: PubChem's notifications for yttrium oxide, the stabiliser, include H315 (skin irritation, 43.6%), H319 (serious eye irritation, 36.7%) and H335 (respiratory irritation, 43.6%); PubChem also lists H413 (long-lasting harmful effects to aquatic life) at 100%. Half of 548 reports find no GHS hazard.
      ghs:
        - H315
        - H319
        - H335
        - H413
      source: pubchem-y2o3
      where: GHS Classification, Hazard Statements (CID 159374)
  failure_risks:
    - mode: Brittle fracture under tension or impact
      trigger: Tensile load, bending or impact on a part with a flaw or sharp corner
      consequence: CoorsTek lists a fracture toughness of 13 MPa√m for its sintered YTZP (notched beam). A flaw or sharp corner lowers the load a ceramic part can carry, and the toughness value is measured on a specimen.
      severity: moderate
      source: coors-chart
      where: Properties table, Fracture Toughness row, YTZP (Sintered) column
    - mode: Ageing in hot water or steam (low-temperature degradation)
      trigger: Long exposure to hot water or steam; the paper's ageing test is an autoclave at 134 °C for 5 h
      consequence: The paragraph citing reference 31 reports about 12% flexural strength loss from a tetragonal to monoclinic transformation, and a 550 MPa cyclic fatigue limit for the degraded samples.
      severity: moderate
      source: scielo-3ytzp
      where: Text paragraph that cites reference 31
    - mode: Thermal shock of a CoorsTek YTZP part
      trigger: Rapid heating or quenching of a part
      consequence: CoorsTek lists a thermal shock temperature difference of 350 °C for its sintered YTZP (quenched into water, chart note 3).
      severity: moderate
      source: coors-chart
      where: Thermal Shock Resistance row (note 3), YTZP (Sintered) column
    - mode: Thermal shock of a Morgan 3Y-TZP part
      trigger: Rapid heating or quenching of a part
      consequence: Morgan lists a thermal shock resistance of 200 °C for its 3Y-TZP grade; the test method is not printed.
      severity: moderate
      source: morgan-3ytzp
      where: Physical Properties, Thermal Shock Resistance row
  side_effects:
    - text: The paper attributes the strength of Y-TZP to the tetragonal to monoclinic transformation, which brings consequent microcracking; the volumetric expansion and shear stress of the transformation inhibit crack propagation around the crack tip.
      affects: Microstructure around cracks in the ceramic
      source: scielo-3ytzp
      where: Introduction, paragraph on the tetragonal to monoclinic transformation
  handling:
    - text: 'Treat yttria (yttrium oxide) powder as an irritant: PubChem lists H315, H319 and H335 for yttrium oxide.'
      source: pubchem-y2o3
      where: GHS Classification, Hazard Statements (CID 159374)
    - text: 'Read the supplier''s values for the grade: CoorsTek says its values vary with the method of manufacture, size and shape of the part.'
      source: coors-chart
      where: Chart footnote on property values
  mitigations:
    - text: Ask the supplier for specified values for critical parts; CoorsTek says close control of most properties can be maintained if specified.
      source: coors-chart
      where: Chart footnote on property values
    - text: 'Avoid long exposure to hot water or steam: the paper''s ageing test is 134 °C for 5 h in an autoclave, and a cited study reports about 12% strength loss after hydrothermal ageing.'
      source: scielo-3ytzp
      where: Text paragraph that cites reference 31
uses:
  - application: mechanisms
    device: Blades and cutting edges (wear parts)
    example: Morgan lists its 3Y-TZP grade for blades and cutting edges, where the fine grain structure is an advantage, and cites excellent wear and abrasion resistance.
    source: morgan-3ytzp
    where: Typical Applications and Prime Features
  - application: mechanisms
    device: Pump and valve components, gas and oil field parts, solids handling
    example: Morgan lists pump and valve components, gas and oil field applications, and solids handling for the same grade.
    source: morgan-3ytzp
    where: Typical Applications
supply:
  - subject: Zirconium (from zircon concentrate)
    abundance: 'USGS: world reserves of zirconium, as ZrO2 content, are more than 70,000 thousand metric tons; reserves for Australia, China, Indonesia and South Africa are reported separately.'
    producers:
      - country: Australia
        share_percent: 33.3
        year: 2025
      - country: South Africa
        share_percent: 22.5
        year: 2025
      - country: Mozambique
        share_percent: 13.3
        year: 2025
      - country: China
        share_percent: 8.3
        year: 2025
      - country: Senegal
        share_percent: 5.8
        year: 2025
      - country: Indonesia
        share_percent: 4.3
        year: 2025
      - country: Madagascar
        share_percent: 2.2
        year: 2025
      - country: Sierra Leone
        share_percent: 2.1
        year: 2025
      - country: Other countries
        share_percent: 3.3
        year: 2025
    critical_lists:
      - list: 'EU critical raw materials list, 2023 (EC page, ec-crm): zirconium is not named'
        listed: false
    recycling: 'USGS: companies in Oregon and Utah recycled zirconium from new scrap generated during metal production; refractories are often recycled but could not be quantified.'
    substitutes:
      - 'USGS: chromite and olivine can substitute for zircon in some foundry applications; dolomite and spinel refractories can substitute in certain high-temperature applications.'
    source: usgs-zrhf
    where: 'World Mine Production and Reserves table (thousand metric tons; 2024 and 2025e columns; the shares are calculated by Space Mushroom against the printed 2025e world total of 1,200 thousand t; the United States line is not used); Recycling; Substitutes; Import sources 2021 to 2024 for zirconium ores and concentrates: South Africa 48%, Australia 35%, Senegal 15%, other 2%.'
  - subject: Hafnium (produced with zircon)
    abundance: 'USGS: world primary hafnium production data and quantitative hafnium resources were not available; hafnium resources are associated with zircon and baddeleyite.'
    critical_lists:
      - list: 'EU critical raw materials list, 2023 (EC page, ec-crm): hafnium is named'
        listed: true
    recycling: 'USGS: hafnium metal recycling was minimal.'
    substitutes:
      - 'USGS: boron or cadmium-silver-indium alloys can substitute for hafnium metal in nuclear control rods; zirconium can be used interchangeably with hafnium in certain superalloys.'
    source: usgs-zrhf
    where: World Mine Production and Reserves (hafnium), World Resources, Substitutes
  - subject: Yttrium (the stabiliser, as Y2O3)
    abundance: 'USGS: 2025 world mine production of Y2O3 equivalent in rare-earth mineral concentrates was 10,000 to 15,000 tons; global yttrium reserves were not quantified.'
    producers:
      - country: China
        year: 2025
      - country: Burma
        year: 2025
    recycling: 'USGS: yttrium recycling is insignificant.'
    substitutes:
      - 'USGS: as a stabiliser in zirconia ceramics, Y2O3 may be substituted with calcium oxide or magnesium oxide, but the substitutes generally impart lower toughness.'
    source: usgs-yttrium
    where: 'Domestic Production and Use; World Mine Production and Reserves (USGS names China as producing most of the world supply and Burma as a significant producer, with no shares printed); Recycling; Substitutes; Events, Trends and Issues (April 2025 export controls on yttrium metals, oxides, alloys and compounds); US imports of yttrium alloys, compounds and metals: China 70%, Germany 11%, Austria 8%, Republic of Korea 4%, other 7%.'
documents:
  - title: CoorsTek Ceramic Properties Standard chart, 8510-1042 Rev. J (copy hosted by the University of Chicago)
    type: datasheet
    url: https://psec.uchicago.edu/ceramics/CoorsTek%208510-1042_Ceramic_Material_Properties.pdf
    year: 2008
  - title: 'Morgan Advanced Materials data sheet: Nilcra Zirconia 3Y-TZP Grade'
    type: datasheet
    url: https://morgantechnicalceramics.com/media/4499/nilcra-zirconia-3y-tzp-grade.pdf
    year: 2013
  - title: A Strength Behavior Approach for 3Y-TZP Ceramics Dental Implants Based on Finite Element Simulations (Materials Research 26, open access)
    type: paper
    url: https://scielo.br/j/mr/a/yf7tMcLz47jz6cVynWFrLSQ/?lang=en
    year: 2023
  - title: 'USGS Mineral Commodity Summaries 2026: Zirconium and Hafnium'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-zirconium-hafnium.pdf
    year: 2026
  - title: 'USGS Mineral Commodity Summaries 2026: Yttrium'
    type: report
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-yttrium.pdf
    year: 2026
  - title: 'PubChem: Zirconium dioxide (CID 62395), GHS classification and identifiers'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/62395
    year: 2026
  - title: 'PubChem: Yttrium oxide (CID 159374), GHS classification'
    type: database
    url: https://pubchem.ncbi.nlm.nih.gov/compound/159374
    year: 2026
  - title: 'Wikipedia: Yttria-stabilized zirconia (composition and naming only)'
    type: database
    url: https://en.wikipedia.org/wiki/Yttria-stabilized_zirconia
  - title: 'European Commission: critical raw materials (list of 2023)'
    type: report
    url: https://single-market-economy.ec.europa.eu/sectors/raw-materials/areas-specific-interest/critical-raw-materials_en
    year: 2023
gaps:
  - No 8YSZ value for thermal barrier coatings or fuel-cell electrolytes is entered. The open 8YSZ papers found earlier (UNIMORE repository, RSC 2024, preprints.org) returned challenge or error pages in this run, so no 8YSZ property was read on a page.
  - ISO 13356 and ASTM F1873 are not printed on any page read in this run, so they are not listed as designations.
  - Electrical resistivity is printed only as an exponent (above 10^13 ohm-cm for CoorsTek; above 10^11 ohm-cm for Morgan). The verify step cannot match that notation, so no resistivity value is entered.
  - The Morgan datasheet prints no test method for its values; the method and conditions fields say so.
  - The CoorsTek chart does not print the mol% yttria or the phase of its YTZP columns; those values are recorded as Y2O3 partially stabilised zirconia with mol% not printed.
  - CoorsTek's HIPed YTZP column (flexural strength 1720 MPa, same chart) is not entered because it is a different form from the sintered column.
  - Acid, alkali and solubility resistance of Y-TZP (for example ISO 6872 tests) were not read in this run. The corrosion entry covers hydrothermal ageing only, and its rating is unknown because the source gives no rating.
  - 'The low-temperature degradation limit: the paper gives about 12% strength loss and a 550 MPa cyclic fatigue limit for aged samples, both in a paragraph that cites reference 31. No standard monoclinic-content limit was printed on a page read.'
  - The USGS 2025 critical minerals list page returned a stub, so the US list status of zirconium and yttrium was not read. The EU page names hafnium and heavy rare earth elements; it names neither zirconium nor yttrium.
  - Zirconium producer shares are calculated by Space Mushroom from the printed 2025e mine production against the printed world total of 1,200 thousand t. The United States line is not used because its figures could not be separated in the text.
  - USGS prints no country shares for yttrium mine production; China and Burma are named without shares.
  - Atomic weights are not entered in the recipe, since no fetched page prints them for this record.
  - Hazard data rest on PubChem; no supplier safety data sheet for zirconia or yttria powder was opened.
  - No lattice constants or measured density for 8YSZ are entered. The 6.05 g/cm3 theoretical density used by the 3Y-TZP paper is an assumed value and is not entered.
license: CC-BY-4.0
updated: '2026-10-24'
review:
  status: draft
  method: assistant
  checked_values: 29
  unreachable: 5
  caveats: 3
  note: 'Written by an AI assistant on 2026-10-24 from pages fetched in this run: CoorsTek chart (sintered YTZP column), Morgan Nilcra 3Y-TZP datasheet, Materials Research 26 (2023) paper, USGS MCS 2026 zirconium and hafnium and yttrium chapters, PubChem CIDs 62395 and 159374, Wikipedia (composition and naming only) and the EC critical raw materials page. Unreachable in this run: UNIMORE 8YSZ PDF (challenge page), RSC 2024 YSZ paper (stub), preprints.org 2017 preprint (error), DOAJ record (challenge page), USGS 2025 critical list page (stub). Caveats: CoorsTek phase and yttria not printed; Morgan test methods not printed; ageing values come from a paragraph that cites another study.'
sources:
  coors-chart:
    title: CoorsTek Ceramic Properties Standard (chart of alumina, zirconia and carbide grades)
    id: CoorsTek F0801 8510-1042 Rev. J, 2008
    url: https://psec.uchicago.edu/ceramics/CoorsTek%208510-1042_Ceramic_Material_Properties.pdf
    year: 2008
    kind: datasheet
    license: supplier document, linked not reproduced
  morgan-3ytzp:
    title: 'Morgan Advanced Materials data sheet: Nilcra Zirconia 3Y-TZP Grade'
    id: Morgan Advanced Materials, copyright 2013
    url: https://morgantechnicalceramics.com/media/4499/nilcra-zirconia-3y-tzp-grade.pdf
    year: 2013
    kind: datasheet
    license: supplier document, linked not reproduced
  scielo-3ytzp:
    title: A Strength Behavior Approach for 3Y-TZP Ceramics Dental Implants Based on Finite Element Simulations
    id: doi:10.1590/1980-5373-MR-2022-0110 (Materials Research 26, 2023)
    url: https://scielo.br/j/mr/a/yf7tMcLz47jz6cVynWFrLSQ/?lang=en
    year: 2023
    kind: paper
    license: open access under a Creative Commons Attribution License, as printed on the page
  usgs-zrhf:
    title: 'Mineral Commodity Summaries 2026: Zirconium and Hafnium'
    id: USGS MCS 2026, February 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-zirconium-hafnium.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  usgs-yttrium:
    title: 'Mineral Commodity Summaries 2026: Yttrium'
    id: USGS MCS 2026, February 2026
    url: https://pubs.usgs.gov/periodicals/mcs2026/mcs2026-yttrium.pdf
    year: 2026
    kind: report
    license: public domain (USGS)
  pubchem-zro2:
    title: PubChem compound record, Zirconium dioxide (CID 62395)
    id: CID 62395; CAS 1314-23-4
    url: https://pubchem.ncbi.nlm.nih.gov/compound/62395
    year: 2026
    kind: database
    license: public domain (NCBI)
  pubchem-y2o3:
    title: PubChem compound record, Yttrium oxide (CID 159374)
    id: CID 159374
    url: https://pubchem.ncbi.nlm.nih.gov/compound/159374
    year: 2026
    kind: database
    license: public domain (NCBI)
  wikipedia-ysz:
    title: 'Wikipedia: Yttria-stabilized zirconia (used for composition and naming only)'
    id: en.wikipedia.org, Yttria-stabilized zirconia
    url: https://en.wikipedia.org/wiki/Yttria-stabilized_zirconia
    kind: web
    license: CC BY-SA 4.0
  ec-crm:
    title: 'European Commission: critical raw materials, list of 2023 under the Critical Raw Materials Act'
    id: Regulation (EU) 2024/1252 page context; 2023 list
    url: https://single-market-economy.ec.europa.eu/sectors/raw-materials/areas-specific-interest/critical-raw-materials_en
    year: 2023
    kind: web
    license: European Commission web page
story:
  recipe:
    line: Zirconium dioxide (ZrO2) stabilised with yttria (Y2O3). Morgan's datasheet gives the grade as 3 mol% (5.2 wt%) Y2O3 in ZrO2. The 3Y-TZP paper makes its samples by compacting the powder and sintering it at 1500 °C for 2 h; it reports relative density above 99% and submicron, equiaxed tetragonal grains.
    parts:
      - name: Zirconium
        symbol: Zr
        share_note: 1 atom per formula unit of ZrO2 (Morgan datasheet)
        role: The host metal. Each formula unit has one zirconium atom bonded to oxygen.
      - name: Oxygen
        symbol: O
        share_note: 2 atoms per formula unit of ZrO2 (Morgan datasheet)
        role: Two oxygen atoms per zirconium make the ZrO2 oxide lattice.
      - name: Yttrium
        symbol: 'Y'
        share_note: 3 mol% of Y2O3 in ZrO2 (5.2 wt% Y2O3, Morgan datasheet)
        role: The stabiliser. Yttria is added so the zirconia keeps a tetragonal crystal form; the grade name, yttria-stabilised tetragonal zirconia polycrystal (Y-TZP), says so.
  risk_groups:
    - title: For people
      level: 0
      verdict: Mostly not classified hazardous
      lead: PubChem classes zirconium dioxide as not hazardous in most reports. Yttria, the stabiliser, carries irritant codes in some reports.
      points:
        - label: Zirconium dioxide
          line: PubChem's GHS entry reads Not Classified, and 93.2% of company reports (1040 of 1116) do not meet any GHS hazard criterion.
        - label: Yttria powder
          line: PubChem lists skin, eye and respiratory irritation codes (H315, H319, H335) for yttrium oxide in 36.7 to 43.6% of notifications.
    - title: If it fails
      lead: These results come from manufacturer tests and one cited ageing study, not from incidents in service.
      points:
        - label: Cracking
          line: CoorsTek's sintered YTZP has a fracture toughness of 13 MPa√m (notched beam) and a flexural strength of 1240 MPa. Ceramics break by crack growth, so flaws and sharp corners set the risk.
        - label: Ageing in steam or hot water
          line: The paper's ageing test is an autoclave at 134 °C for 5 h (about 30 years in the oral environment, per the paper). A study it cites reports about 12% flexural strength loss, and aged samples had a cyclic fatigue limit of 550 MPa.
        - label: Thermal shock
          line: CoorsTek lists a thermal shock temperature difference of 350 °C for its sintered YTZP; Morgan lists 200 °C for its 3Y-TZP grade.
    - title: Handling and storage
      gap: No supplier safety data sheet for zirconia powder was opened in this run.
      points:
        - label: Powder
          line: 'Treat yttria powder as an irritant: PubChem lists H315, H319 and H335 for yttrium oxide.'
        - label: Supplier values
          line: CoorsTek says its values vary with the method of manufacture, size and shape of the part; ask for specified values for critical parts.
  why: 'Yttria-stabilised zirconia (YSZ) is zirconium dioxide with yttria (Y2O3) added to hold a tetragonal crystal form. The grade the sources describe in most detail is 3Y-TZP, with 3 mol% yttria. The 3Y-TZP paper attributes its strength to the tetragonal to monoclinic transformation: the volume and shear stress that come with the change inhibit crack growth. The same transformation is the weak point. In hot water or steam the tetragonal phase transforms, and the strength falls.'
  uses:
    - where: Wear parts and cutting edges
      line: Morgan Advanced Materials lists its 3Y-TZP grade for blades and cutting edges, where the fine grain structure is an advantage, and cites excellent wear and abrasion resistance.
    - where: Pumps, valves and solids handling
      line: The same datasheet lists pump and valve components, gas and oil field parts and solids handling for the grade.
  can_do:
    - label: Strength
      value: 1240 MPa
      line: CoorsTek's sintered YTZP has a flexural strength of 1240 MPa at 20 °C (ASTM F417). Morgan's 3Y-TZP grade lists 1000 MPa at 20 °C. The 3Y-TZP paper measured 1192 MPa by piston-on-three-balls bending on its own samples sintered at 1500 °C.
    - label: Toughness
      value: 13 MPa√m
      line: CoorsTek lists a fracture toughness of 13 MPa√m for its sintered YTZP (notched beam). Morgan lists 10 MPa√m for its 3Y-TZP grade.
    - label: Hardness
      value: 12.7 GPa
      line: CoorsTek lists a Knoop hardness of 12.7 GPa at a 1000 gm load. Morgan lists a Vickers HV0.3 hardness of 1300 kg/mm2.
    - label: Stiffness
      value: 210 GPa
      line: CoorsTek's sintered YTZP has an elastic modulus of 210 GPa (ASTM C848), and Morgan's 3Y-TZP grade 205 GPa. The paper's own samples measured 195 GPa by impulse excitation.
    - label: Heat
      value: 1500 °C
      line: CoorsTek lists a maximum use temperature of 1500 °C with no load on the part. Morgan lists 800 °C for its 3Y-TZP grade, with the load basis not printed.
    - label: Thermal conduction
      value: 2.2 W/(m·K)
      line: CoorsTek's sintered YTZP conducts heat at 2.2 W/(m·K) at 20 °C; Morgan's 3Y-TZP grade is rated at 3.0 W/(m·K).
    - label: Electrical strength
      value: 9.0 kV/mm
      line: CoorsTek lists a dielectric strength of 9.0 kV/mm for its sintered YTZP (ac, ASTM D116, samples 0.25 inch thick).
  compare: The two Y-TZP grades in the record differ, and the values are compared as printed. CoorsTek's sintered YTZP is higher on flexural strength and fracture toughness (1240 MPa and 13 MPa√m, against 1000 MPa and 10 MPa√m for Morgan's 3Y-TZP grade), and it expands more on heating (10.3 against 9 ppm/K). Morgan's grade conducts heat better (3.0 against 2.2 W/(m·K)) and is rated for a lower maximum use temperature (800 against 1500 °C), with the test basis not printed for that rating.
  compare_rows:
    - label: Flexural strength
      benchmark: flexural_strength
    - label: Fracture toughness
      benchmark: fracture_toughness
    - label: Thermal conductivity
      benchmark: thermal_conductivity
  handling:
    - 'Read the supplier''s values for the grade: CoorsTek says values vary with the method of manufacture, size and shape of the part.'
    - 'Treat yttria powder as an irritant: PubChem lists H315, H319 and H335 for yttrium oxide.'
    - 'Keep parts away from long exposure to hot water or steam: the paper''s ageing test is 134 °C for 5 h in an autoclave.'
    - 'Avoid rapid heating or quenching: thermal shock limits are 350 °C (CoorsTek) and 200 °C (Morgan).'
  good_for:
    - Wear and cutting parts. Morgan lists blades, cutting edges and pump and valve parts for its 3Y-TZP grade.
    - High strength and toughness. CoorsTek's sintered YTZP has a flexural strength of 1240 MPa and a fracture toughness of 13 MPa√m.
    - High-temperature parts with no load. CoorsTek lists a maximum use temperature of 1500 °C for its YTZP.
  watch_out:
    - Hot water and steam. A cited study reports about 12% strength loss after hydrothermal ageing; the paper's ageing test is 134 °C for 5 h in an autoclave.
    - Thermal shock. The limits are 200 °C for Morgan's grade and 350 °C for CoorsTek's YTZP.
    - Grade and maker. Morgan's 3Y-TZP is rated 800 °C, and CoorsTek's YTZP 1500 °C; the test basis of the Morgan rating is not printed.
    - Yttria supply. USGS reports that China tightened its export controls on yttrium metals, oxides, alloys and compounds in April 2025.
  verdict: 3Y-TZP is a strong, tough ceramic for wear and structural parts that stay dry or cool. Its limits are ageing in hot water or steam and thermal shock. Values for the 8YSZ coating and fuel-cell grade are not in this profile yet.