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Titanium Ti-15Mo-2.7Nb-3Al-0.2Si-CR (Cold rolled)

Supply condition

UNS R58210

Cold-rolled thin strip and MMC matrix foil (0.1–0.3 mm) supplied work-hardened; solution treat or age after lay-up/consolidation.

High cost $$$$

Values for the CR condition

Other Ti-15Mo-2.7Nb-3Al-0.2Si tempers and conditions

Ti-15Mo-2.7Nb-3Al-0.2Si is listed in 4 conditions; see the grade overview at Ti-15Mo-2.7Nb-3Al-0.2Si.

Compare all 4 conditionsHide
Condition · open for datasheetBest forYield MPaTensile MPaElong. %HardnessConductivity
STDefault
Solution annealed
Standard as-supplied condition for sheet, foil and bar: soft, ductile, cold-formable and weldable, aged after fabrication if strength is required.8108401828 HRC—
CRThis page
Cold rolled
Cold-rolled thin strip and MMC matrix foil (0.1–0.3 mm) supplied work-hardened; solution treat or age after lay-up/consolidation.9501,000833 HRC1.3 % IACS
STA 595 °C
Choose when thermal stability up to ~600 °C, creep resistance and better ductility/toughness matter more than peak tensile strength.1,0501,140937 HRC—
STA 538 °C
Pick for maximum room- and elevated-temperature strength in airframe/engine parts once forming and welding are complete.1,2101,310641 HRC—

What is Ti-15Mo-2.7Nb-3Al-0.2Si-CR?

Ti-15Mo-2.7Nb-3Al-0.2Si-CR is Ti-15Mo-2.7Nb-3Al-0.2Si supplied in the CR condition — cold-rolled thin strip and MMC matrix foil (0.1–0.3 mm) supplied work-hardened; solution treat or age after lay-up/consolidation. Ti-15Mo-2.7Nb-3Al-0.2Si-CR has a yield strength of 950 MPa (138 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 88% of titanium grades. Elongation at break is 8% and the elastic modulus is 85 GPa (12.3 Msi). Ti-15Mo-2.7Nb-3Al-0.2Si-CR has a density of 4.94 g/cm³ (0.178 lb/in³), heavier than 97% of titanium grades. It melts at 1,600°C (2,912 °F). ST is the default condition FabDigit quotes; CR is available on request or by drawing note.

Advantages

  • High strength — 950 MPa (138 ksi), better than 88% of titanium grades
  • High service temperature — 400°C (752 °F), better than 78% of titanium grades

Limitations

  • Limited ductility — 8%, worse than 99% of titanium grades
  • Low fracture toughness — 45 MPa·√m (41 ksi·√in), worse than 98% of titanium grades
  • Low stiffness — 85 GPa (12.3 Msi), worse than 95% of titanium grades
  • Difficult to weld — 50/100, worse than 89% of titanium grades

Ti-15Mo-2.7Nb-3Al-0.2Si-CR properties

Typical room-temperature values for Ti-15Mo-2.7Nb-3Al-0.2Si-CR; 22 are specific to this condition. Other listed values are Ti-15Mo-2.7Nb-3Al-0.2Si reference data and may not represent this condition. Bars are the position among titanium grades.

Physical3

Ti-15Mo-2.7Nb-3Al-0.2Si-CR has a density of 4.94 g/cm³ (0.178 lb/in³), heavier than 97% of titanium grades. It melts at 1,600°C (2,912 °F).

Density4.94 g/cm³0.18 lb/in³
Melting Point (Solidus)1,600°C2,912 °F
Liquidus Temperature1,650°C3,002 °F

Mechanical14

Ti-15Mo-2.7Nb-3Al-0.2Si-CR has a yield strength of 950 MPa (138 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 88% of titanium grades. Elongation at break is 8% and the elastic modulus is 85 GPa (12.3 Msi).

Elastic (Young's) Modulus85 GPa12.3 Msi
Shear Modulus30 GPa4.4 Msi
Bulk Modulus79 GPa11.5 Msi
Poisson's Ratio0.33
Tensile Strength (Ultimate)1,000 MPa145 ksi
Yield Strength (0.2% offset)950 MPa138 ksi
Elongation at Break8%
Reduction in Area20%
Compressive Strength1,000 MPa145 ksi
Shear Strength620 MPa89.9 ksi
Fatigue Strength (Endurance Limit)520 MPa75.4 ksi
Fracture Toughness (K_IC)45 MPa·√m41 ksi·√in
Hardness, Rockwell C33 HRC
Hardness, Vickers330 HV

Thermal6

Ti-15Mo-2.7Nb-3Al-0.2Si-CR is rated for continuous service to 400°C (752 °F). It conducts heat at 7.6 W/m·K (4.39 BTU/hr·ft·°F), worse than 59% of titanium grades. Thermal expansion is 7.7 µm/m·K (4.28 µin/in·°F).

Thermal Conductivity7.6 W/m·K4.4 BTU/hr·ft·°F
Specific Heat Capacity500 J/kg·K0.12 BTU/lb·°F
Thermal Expansion (CTE, 20–100 °C)7.7 µm/m·K4.3 µin/in·°F
Latent Heat of Fusion360 J/g155 BTU/lb
Max Service Temperature (continuous)400°C752 °F
Min Service Temperature-70°C-94 °F

Electrical3

Ti-15Mo-2.7Nb-3Al-0.2Si-CR conducts electricity at 1.3 % IACS, worse than 52% of titanium grades.

Electrical Conductivity1.3 % IACS
Electrical Resistivity1.4×10⁻⁶ Ω·m55.1 µΩ·in
Magnetic Responsenon-magnetic

Chemical & Environmental3

Corrosion resistance is excellent (92/100), better than 53% of titanium grades.

Galvanic Potential (seawater, vs SCE)-0.1 V
Corrosion ResistanceExcellent92/100
Chemical Resistance SummaryExcellent in seawater, chlorides and hot-salt environments; the 15 % Mo markedly improves resistance to reducing acids (HCl, H2SO4) and crevice corrosion versus Ti-6Al-4V; attacked by HF, hot concentrated oxidizing chlorides, and absorbs hydrogen above ~80 °C in strong acids.

Sustainability4

Producing a kilogram of Ti-15Mo-2.7Nb-3Al-0.2Si-CR takes about 700 MJ of energy and emits 42 kg of CO₂ — more than 74% of titanium grades. Typical recycled content is 15%.

Embodied Energy (primary production)700 MJ/kg300,946 BTU/lb
Embodied Carbon (primary production)42 kg CO₂/kg
Embodied Water550 L/kg65.9 gal/lb
Typical Recycled Content15%

Manufacturability8

Ti-15Mo-2.7Nb-3Al-0.2Si-CR's machinability is poor (15/100, worse than 97% of titanium grades); weldability fair (50/100); formability fair (45/100).

MachinabilityPoor15/100
Machinability Rating (AISI 1212 = 100 %)12%
WeldabilityFair50/100
Formability (cold)Fair45/100
CastabilityPoor30/100
Brazeability / SolderabilityFair45/100
PolishabilityVery good70/100
Anodizing Responsegood — anodizes to interference colours (Type II/III Ti anodize) and can be given oxide/lubricious coatings; not a load-bearing coating

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

Working with Ti-15Mo-2.7Nb-3Al-0.2Si-CR

Is Ti-15Mo-2.7Nb-3Al-0.2Si easy to machine?

Machine like a tough β-Ti alloy: rigid setups, sharp uncoated carbide or PVD-coated tools, low surface speed (15–30 m/min aged), heavy positive rake, generous flood coolant to counter the 7.6 W/m·K conductivity; avoid dwelling and rubbing which work-hardens the surface.

Can Ti-15Mo-2.7Nb-3Al-0.2Si be welded?

GTAW, plasma and EB/laser welding are practical in the solution-treated condition with full inert-gas or vacuum shielding; welds age-harden with the parent but ductility drops, so post-weld solution treat + age (or age only) and avoid welding fully aged material.

Can Ti-15Mo-2.7Nb-3Al-0.2Si be formed, bent or molded?

Excellent cold formability for a high-strength Ti alloy in the ST condition — cold rollable to thin foil, brake-formable with generous radii and ~2–3× springback allowance; hot form/superplastically form 700–815 °C, then age.

What surface finishes work on Ti-15Mo-2.7Nb-3Al-0.2Si?

Pickle in HNO3/HF after hot work to remove alpha case; Ti anodize (AMS 2488) or oxide/MoS2 coatings for galling control; grit blast + primer for painting; takes a good mechanical polish but is prone to galling against itself, so use dry-film lube or plating on threads.

Ti-15Mo-2.7Nb-3Al-0.2Si 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
Moβ stabilizer, oxidation/acid resistance14 – 1615
Nb2.2 – 3.22.7
Al2.5 – 3.53
Sicreep and oxidation resistance0.15 – 0.250.2
Fe≤ 0.4—
O≤ 0.17—
C≤ 0.05—
N≤ 0.05—
Hmax, sheet/strip≤ 0.02—
Y≤ 0.01—
Other, eachresidual elements, 0.40 max total≤ 0.1—
Tibalance—

Ti-15Mo-2.7Nb-3Al-0.2Si-CR — frequently asked

What is Ti-15Mo-2.7Nb-3Al-0.2Si-CR used for?

Ti-15Mo-2.7Nb-3Al-0.2Si-CR is typically used for exhaust system components, MMC matrix and high-temperature airframe parts. In short: most oxidation-resistant beta Ti; 480 °C service capability; cold-rollable to foil.

What is the yield strength of Ti-15Mo-2.7Nb-3Al-0.2Si-CR?

Ti-15Mo-2.7Nb-3Al-0.2Si-CR has a typical yield strength of 950 MPa (138 ksi) and a tensile strength of 1,000 MPa (145 ksi) — stronger than 88% of titanium grades. Strength varies by condition: see the 4 listed tempers.

Is Ti-15Mo-2.7Nb-3Al-0.2Si-CR easy to machine?

Not especially — machinability is rated poor (15/100, worse than 97% of titanium grades). Machine like a tough β-Ti alloy: rigid setups, sharp uncoated carbide or PVD-coated tools, low surface speed (15–30 m/min aged), heavy positive rake, generous flood coolant to counter the 7.6 W/m·K conductivity; avoid dwelling and rubbing which work-hardens the surface.

Can Ti-15Mo-2.7Nb-3Al-0.2Si-CR be welded?

With care — weldability is rated fair (50/100). GTAW, plasma and EB/laser welding are practical in the solution-treated condition with full inert-gas or vacuum shielding; welds age-harden with the parent but ductility drops, so post-weld solution treat + age (or age only) and avoid welding fully aged material.

What surface finishes work on Ti-15Mo-2.7Nb-3Al-0.2Si-CR?

Pickle in HNO3/HF after hot work to remove alpha case; Ti anodize (AMS 2488) or oxide/MoS2 coatings for galling control; grit blast + primer for painting; takes a good mechanical polish but is prone to galling against itself, so use dry-film lube or plating on threads.

Can Ti-15Mo-2.7Nb-3Al-0.2Si-CR be formed, bent or molded?

Excellent cold formability for a high-strength Ti alloy in the ST condition — cold rollable to thin foil, brake-formable with generous radii and ~2–3× springback allowance; hot form/superplastically form 700–815 °C, then age.

What is the maximum service temperature of Ti-15Mo-2.7Nb-3Al-0.2Si-CR?

Ti-15Mo-2.7Nb-3Al-0.2Si-CR is rated for continuous use to about 400°C (752 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.

What is the difference between Ti-15Mo-2.7Nb-3Al-0.2Si-ST and Ti-15Mo-2.7Nb-3Al-0.2Si STA-538?

ST is the default condition — standard as-supplied condition for sheet, foil and bar: soft, ductile, cold-formable and weldable, aged after fabrication if strength is required. STA-538: pick for maximum room- and elevated-temperature strength in airframe/engine parts once forming and welding are complete. Yield strength is 810 MPa in ST versus 1,210 MPa in STA-538.

Sources

  1. ASTM B265 / B348 — Titanium Grade 21 (UNS R58210) — ASTM International (2020)
  2. TIMETAL 21S (Beta 21S) alloy data sheet — TIMET (2000)
  3. ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
  4. Materials Properties Handbook: Titanium Alloys — ASM International (1994)
  5. MMPDS / MIL-HDBK-5 titanium alloy chapters (typical values) — Battelle/FAA (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.