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Precious Metal 90Pt-10Ir-ANN (Annealed)

Heat-treated state · default condition

Default stock condition for wire, strip and contact rivets that must be drawn, coined, bent or welded before use.

High cost $$$$

Values for the ANN condition

Other 90Pt-10Ir tempers and conditions

90Pt-10Ir is listed in 3 conditions; see the grade overview at 90Pt-10Ir.

Compare all 3 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
ANNDefaultThis page
Annealed
Default stock condition for wire, strip and contact rivets that must be drawn, coined, bent or welded before use.20541528125 HB7 % IACS
Half hard
Compromise condition for contact springs and slip-ring wire needing stiffness while retaining some bending ductility.4806208190 HV6.9 % IACS
Hardened
Choose for spring contacts, probe needles and wear surfaces where maximum hardness and elastic stiffness matter more than formability.690830223 HRC6.8 % IACS

What is 90Pt-10Ir-ANN?

90Pt-10Ir-ANN is 90Pt-10Ir heat treated to ANN — default stock condition for wire, strip and contact rivets that must be drawn, coined, bent or welded before use. 90Pt-10Ir-ANN has a yield strength of 205 MPa (29.7 ksi) and a tensile strength of 415 MPa (60.2 ksi) — stronger than 57% of precious metal grades. Elongation at break is 28% and the elastic modulus is 190 GPa (27.6 Msi). 90Pt-10Ir-ANN has a density of 21.55 g/cm³ (0.779 lb/in³), heavier than 99% of precious metal grades. It melts at 1,780°C (3,236 °F).

Advantages

  • Good corrosion resistance — 100/100, better than 98% of precious metal grades
  • High service temperature — 1,200°C (2,192 °F), better than 97% of precious metal grades
  • Stiff — 190 GPa (27.6 Msi), better than 94% of precious metal grades

Limitations

  • Heavy — 21.55 g/cm³ (0.779 lb/in³), worse than 99% of precious metal grades
  • Poor heat conductor — 31 W/m·K (17.9 BTU/hr·ft·°F), worse than 92% of precious metal grades
  • Low electrical conductivity — 7 % IACS, worse than 89% of precious metal grades
  • Difficult to machine — 30/100, worse than 86% of precious metal grades
  • High embodied carbon — 13,500 kg CO₂/kg, worse than 84% of precious metal grades

90Pt-10Ir-ANN properties

Typical room-temperature values for 90Pt-10Ir-ANN; 18 are specific to this condition. Other listed values are 90Pt-10Ir reference data and may not represent this condition. Bars are the position among precious metal grades.

Physical3

90Pt-10Ir-ANN has a density of 21.55 g/cm³ (0.779 lb/in³), heavier than 99% of precious metal grades. It melts at 1,780°C (3,236 °F).

Density21.55 g/cm³0.78 lb/in³
Melting Point (Solidus)1,780°C3,236 °F
Liquidus Temperature1,800°C3,272 °F

Mechanical12

90Pt-10Ir-ANN has a yield strength of 205 MPa (29.7 ksi) and a tensile strength of 415 MPa (60.2 ksi) — stronger than 57% of precious metal grades. Elongation at break is 28% and the elastic modulus is 190 GPa (27.6 Msi).

Elastic (Young's) Modulus190 GPa27.6 Msi
Shear Modulus72 GPa10.4 Msi
Bulk Modulus290 GPa42.1 Msi
Poisson's Ratio0.39
Tensile Strength (Ultimate)415 MPa60.2 ksi
Yield Strength (0.2% offset)205 MPa29.7 ksi
Elongation at Break28%
Reduction in Area60%
Shear Strength280 MPa40.6 ksi
Fatigue Strength (Endurance Limit)190 MPa27.6 ksi
Hardness, Brinell125 HB
Hardness, Vickers130 HV

Thermal6

90Pt-10Ir-ANN is rated for continuous service to 1,200°C (2,192 °F). It conducts heat at 31 W/m·K (17.9 BTU/hr·ft·°F), worse than 92% of precious metal grades. Thermal expansion is 8.8 µm/m·K (4.89 µin/in·°F).

Thermal Conductivity31 W/m·K17.9 BTU/hr·ft·°F
Specific Heat Capacity132 J/kg·K0.03 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)8.8 µm/m·K4.9 µin/in·°F
Latent Heat of Fusion113 J/g48.6 BTU/lb
Max Service Temperature (continuous)1,200°C2,192 °F
Min Service Temperature-269°C-452 °F

Electrical3

90Pt-10Ir-ANN conducts electricity at 7 % IACS, worse than 89% of precious metal grades.

Electrical Conductivity7 % IACS
Electrical Resistivity2.45×10⁻⁷ Ω·m9.65 µΩ·in
Magnetic Responsenon-magnetic

Chemical & Environmental3

Corrosion resistance is excellent (100/100), better than 98% of precious metal grades.

Galvanic Potential (seawater, vs SCE)0.25 V
Corrosion ResistanceExcellent100/100
Chemical Resistance SummaryEssentially inert to all common acids, alkalis, molten glass, body fluids and oxidizing atmospheres; attacked only by aqua regia (slowly), molten alkali cyanides/peroxides, and by halogens or reducing molten metals (Pb, Bi, Sb, Sn) at high temperature.

Sustainability4

Producing a kilogram of 90Pt-10Ir-ANN takes about 245,000 MJ of energy and emits 13,500 kg of CO₂ — more than 93% of precious metal grades. Typical recycled content is 30%.

Embodied Energy (primary production)245,000 MJ/kg1.05×10⁸ BTU/lb
Embodied Carbon (primary production)13,500 kg CO₂/kg
Embodied Water280,000 L/kg33,551 gal/lb
Typical Recycled Content30%

Manufacturability8

90Pt-10Ir-ANN's machinability is poor (30/100, worse than 86% of precious metal grades); weldability very good (70/100); formability excellent (90/100).

MachinabilityPoor30/100
Machinability Rating (AISI 1212 = 100 %)25%
WeldabilityVery good70/100
Formability (cold)Excellent90/100
CastabilityFair40/100
Brazeability / SolderabilityVery good70/100
PolishabilityExcellent90/100
Anodizing Responsen/a — noble metal, not anodized; surfaces are used bare or laser-textured

Common Calculations5

Specific Strength (UTS / density)calculated19 kN·m/kg
Specific Stiffness (E / density)calculated8.8 MN·m/kg
Modulus of Resiliencecalculated111 kJ/m³
Thermal Diffusivitycalculated10.9 mm²/s
Thermal Shock Resistance Indexcalculated8

Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.

Working with 90Pt-10Ir-ANN

Is 90Pt-10Ir easy to machine?

Gummy and strongly work-hardening — use sharp carbide or diamond tools, light positive-rake cuts, high speed with copious coolant, and collect all swarf for refining.

Can 90Pt-10Ir be welded?

Excellent for resistance, micro-TIG and laser welding of contacts to Cu/Ni carriers; avoid contamination by Pb/Bi/Si and reducing melts that embrittle PGMs.

Can 90Pt-10Ir be formed, bent or molded?

Anneal at 900–1100 °C in air and cold draw/roll in 30–50 % steps; the 10 % Ir grade takes deeper draws and tighter bends than 85Pt-15Ir before intermediate anneals.

What surface finishes work on 90Pt-10Ir?

Takes a permanent mirror polish with no plating or passivation needed; ultrasonic clean and avoid halide residues on switching surfaces.

90Pt-10Ir 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.

ElementSpec limit (wt %)Nominal
Irsolid-solution strengthener9.5 – 10.510
Other PGM + impuritiestotal, Rh/Pd/Ru/Fe/Cu traces≤ 0.15—
Pt≥ 89.5 (balance)—

90Pt-10Ir-ANN — frequently asked

What is 90Pt-10Ir-ANN used for?

90Pt-10Ir-ANN is typically used for precision relay contacts, slip rings and electrode tips. In short: most ductile Pt-Ir grade; stable to 1200 °C; fine-wire drawing grade.

What is the yield strength of 90Pt-10Ir-ANN?

90Pt-10Ir-ANN has a typical yield strength of 205 MPa (29.7 ksi) and a tensile strength of 415 MPa (60.2 ksi) — stronger than 57% of precious metal grades. Strength varies by condition: see the 3 listed tempers.

Is 90Pt-10Ir-ANN easy to machine?

Not especially — machinability is rated poor (30/100, worse than 86% of precious metal grades). Gummy and strongly work-hardening — use sharp carbide or diamond tools, light positive-rake cuts, high speed with copious coolant, and collect all swarf for refining.

Can 90Pt-10Ir-ANN be welded?

Yes — weldability is rated very good (70/100). Excellent for resistance, micro-TIG and laser welding of contacts to Cu/Ni carriers; avoid contamination by Pb/Bi/Si and reducing melts that embrittle PGMs.

What surface finishes work on 90Pt-10Ir-ANN?

Takes a permanent mirror polish with no plating or passivation needed; ultrasonic clean and avoid halide residues on switching surfaces.

Can 90Pt-10Ir-ANN be formed, bent or molded?

Anneal at 900–1100 °C in air and cold draw/roll in 30–50 % steps; the 10 % Ir grade takes deeper draws and tighter bends than 85Pt-15Ir before intermediate anneals.

What is the maximum service temperature of 90Pt-10Ir-ANN?

90Pt-10Ir-ANN is rated for continuous use to about 1,200°C (2,192 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between 90Pt-10Ir-ANN and 90Pt-10Ir-H?

ANN is the default condition — default stock condition for wire, strip and contact rivets that must be drawn, coined, bent or welded before use. H: choose for spring contacts, probe needles and wear surfaces where maximum hardness and elastic stiffness matter more than formability. Yield strength is 205 MPa in ANN versus 690 MPa in H.

Sources

  1. ASTM B684 — Platinum-Iridium Electrical Contact Material — ASTM International (2020)
  2. ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (Precious Metals) — ASM International (1990)
  3. Platinum-Iridium alloy property tables — Johnson Matthey / Heraeus (2022)
  4. PGM physical and electrical property compilation — International Platinum Group Metals Association (2021)

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.