Titanium ERTi-15-ELI (ERTi-15A)
Grade
UNS R54520 · ASTM B863 ERTi-15
Choose for liquid-hydrogen/liquid-helium hardware and any joint needing maximum fracture toughness at -196 to -253 °C.
Values for the ELI condition
Other ERTi-15 tempers and conditions
ERTi-15 is listed in 4 conditions; see the grade overview at ERTi-15.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
ELIThis page ERTi-15A | Choose for liquid-hydrogen/liquid-helium hardware and any joint needing maximum fracture toughness at -196 to -253 °C. | 745 | 810 | 16 | 31 HRC | — |
Stress relieved | Pick when weld residual stress must be cut for dimensional stability, fatigue or stress-corrosion sensitivity, without softening the joint. | 805 | 870 | 13 | 34 HRC | 1.1 % IACS |
Annealed | Use when the whole weldment is annealed with the Grade 6 base metal to homogenise properties and maximise ductility/toughness. | 807 | 861 | 15 | 33 HRC | — |
AWDefault As-welded deposit | Default condition for most Ti-5Al-2.5Sn joints where residual stress is acceptable and no PWHT furnace is available. | 815 | 880 | 11 | 35 HRC | — |
What is ERTi-15-ELI?
ERTi-15-ELI is ERTi-15 in the ELI grade — choose for liquid-hydrogen/liquid-helium hardware and any joint needing maximum fracture toughness at -196 to -253 °C. ERTi-15-ELI has a yield strength of 745 MPa (108 ksi) and a tensile strength of 810 MPa (117 ksi) — stronger than 54% of titanium grades. Elongation at break is 16% and the elastic modulus is 110 GPa (16 Msi). ERTi-15-ELI has a density of 4.48 g/cm³ (0.162 lb/in³), lighter than 71% of titanium grades. It melts at 1,590°C (2,894 °F). AW is the default condition FabDigit quotes; ELI is available on request or by drawing note.
Advantages
- Tough — resists crack growth — 85 MPa·√m (77.4 ksi·√in), better than 91% of titanium grades
- High service temperature — 425°C (797 °F), better than 85% of titanium grades
ERTi-15-ELI properties
Typical room-temperature values for ERTi-15-ELI; 10 are specific to this condition. Other listed values are ERTi-15 reference data and may not represent this condition. Bars are the position among titanium grades.
Physical3
ERTi-15-ELI has a density of 4.48 g/cm³ (0.162 lb/in³), lighter than 71% of titanium grades. It melts at 1,590°C (2,894 °F).
Mechanical16
ERTi-15-ELI has a yield strength of 745 MPa (108 ksi) and a tensile strength of 810 MPa (117 ksi) — stronger than 54% of titanium grades. Elongation at break is 16% and the elastic modulus is 110 GPa (16 Msi).
Thermal6
ERTi-15-ELI is rated for continuous service to 425°C (797 °F). It conducts heat at 7.8 W/m·K (4.51 BTU/hr·ft·°F), worse than 53% of titanium grades. Thermal expansion is 9.4 µm/m·K (5.22 µin/in·°F).
Electrical3
ERTi-15-ELI conducts electricity at 1.1 % IACS, worse than 67% of titanium grades.
Chemical & Environmental3
Corrosion resistance is excellent (90/100), worse than 63% of titanium grades.
Sustainability4
Producing a kilogram of ERTi-15-ELI takes about 650 MJ of energy and emits 42 kg of CO₂ — less than 75% of titanium grades. Typical recycled content is 20%.
Manufacturability7
ERTi-15-ELI's machinability is poor (22/100, worse than 55% of titanium grades); weldability excellent (85/100); formability fair (35/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with ERTi-15-ELI
Is ERTi-15 easy to machine?
Rarely machined as a consumable; the deposited Ti-5Al-2.5Sn machines like Ti-6Al-4V — low speeds (~25–40 m/min carbide), heavy rigid setups, flood coolant, no dwelling to avoid work-hardening and galling.
Can ERTi-15 be welded?
GTAW/GMAW/PAW/EBW with high-purity argon or helium plus trailing shield and backing gas; keep filler and joint degreased and lint-free, interpass <150 °C, and target weld-face color straw or lighter (silver ideal).
Can ERTi-15 be formed, bent or molded?
Weldments are best formed hot (>600 °C) or after full anneal; cold bending is limited to about 4–5 t radius because of the near-α alloy's low ductility and springback.
What surface finishes work on ERTi-15?
Pickle in HNO₃/HF or grit blast plus pickle to strip alpha case and heat tint; color anodizing works well, and shot peening is used to restore fatigue life on welds.
ERTi-15 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 |
|---|---|---|
| Alα-stabiliser, main solid-solution strengthener | 4.7 – 5.6 | 5.1 |
| Snneutral/α strengthener | 2 – 3 | 2.5 |
| Fe0.25 max for ELI (ERTi-15A) | ≤ 0.4 | 0.2 |
| O0.10 max for ELI grade | ≤ 0.12 | 0.08 |
| C | ≤ 0.05 | 0.02 |
| N | ≤ 0.03 | 0.01 |
| Hcritical for weld ductility | ≤ 0.02 | 0.01 |
| Yyttrium limit for filler metal | ≤ 0.01 | — |
| Other, eachresidual elements | ≤ 0.05 | — |
| Other, totalresidual elements | ≤ 0.3 | — |
| Ti | balance | — |
ERTi-15-ELI — frequently asked
What is ERTi-15-ELI used for?
ERTi-15-ELI is typically used for cryogenic tankage welding, aerospace airframe components and high-temperature titanium structures. In short: cryogenic to 480 °C service; weldable near-alpha alloy; matches Grade 6 base metal.
What is the yield strength of ERTi-15-ELI?
ERTi-15-ELI has a typical yield strength of 745 MPa (108 ksi) and a tensile strength of 810 MPa (117 ksi) — stronger than 54% of titanium grades. Strength varies by condition: see the 4 listed tempers.
Is ERTi-15-ELI easy to machine?
Not especially — machinability is rated poor (22/100, worse than 55% of titanium grades). Rarely machined as a consumable; the deposited Ti-5Al-2.5Sn machines like Ti-6Al-4V — low speeds (~25–40 m/min carbide), heavy rigid setups, flood coolant, no dwelling to avoid work-hardening and galling.
Can ERTi-15-ELI be welded?
Yes — weldability is rated excellent (85/100). GTAW/GMAW/PAW/EBW with high-purity argon or helium plus trailing shield and backing gas; keep filler and joint degreased and lint-free, interpass <150 °C, and target weld-face color straw or lighter (silver ideal).
What surface finishes work on ERTi-15-ELI?
Pickle in HNO₃/HF or grit blast plus pickle to strip alpha case and heat tint; color anodizing works well, and shot peening is used to restore fatigue life on welds.
Can ERTi-15-ELI be formed, bent or molded?
Weldments are best formed hot (>600 °C) or after full anneal; cold bending is limited to about 4–5 t radius because of the near-α alloy's low ductility and springback.
What is the maximum service temperature of ERTi-15-ELI?
ERTi-15-ELI is rated for continuous use to about 425°C (797 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between ERTi-15-AW and ERTi-15-ELI?
AW is the default condition — default condition for most Ti-5Al-2.5Sn joints where residual stress is acceptable and no PWHT furnace is available. ELI: choose for liquid-hydrogen/liquid-helium hardware and any joint needing maximum fracture toughness at -196 to -253 °C. Yield strength is 815 MPa in AW versus 745 MPa in ELI.
Sources
- AWS A5.16/A5.16M — Specification for Titanium and Titanium-Alloy Welding Electrodes and Rods — AWS (2013)
- ASTM B863 — Standard Specification for Titanium and Titanium Alloy Wire — ASTM International (2021)
- ASTM B265 — Titanium and Titanium Alloy Strip, Sheet, and Plate (Grade 6) — ASTM International (2020)
- Materials Properties Handbook: Titanium Alloys (Ti-5Al-2.5Sn chapter) — ASM International (1994)
- ASM Handbook Vol.2 — Properties and Selection: Nonferrous Alloys — ASM International (1990)
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.