Refractory Metal Hafnium Hf-1 (R02001) Annealed
Temper · default condition
UNS R02001 · ASTM B776, B777
Standard stocked condition: maximum ductility for forming, machining and welding.
Values for the Annealed condition
Other Hafnium Hf-1 (R02001) tempers and conditions
Hafnium Hf-1 (R02001) is listed in 6 conditions; see the grade overview at Hafnium Hf-1 (R02001).
Compare all 6 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
vacuum arc remelted / EB-melted ingot | Ingot/consumable stock for remelting into superalloys or for further hot working, not a structural condition. | 200 | 400 | 20 | 150 HB | 5.2 % IACS |
AnnealedDefaultThis page recrystallized (mill-annealed sheet, plate, bar) | Standard stocked condition: maximum ductility for forming, machining and welding. | 240 | 450 | 25 | 165 HB | — |
Hot Worked | Pick for thick plate and forged shapes where a final anneal is not required. | 300 | 480 | 20 | 11 HRC | 5.2 % IACS |
Cold Worked and Stress Relieved | Compromise condition: most cold-work strength retained with restored dimensional stability and some ductility. | 500 | 600 | 10 | 19 HRC | 5.1 % IACS |
Cold worked | Use for springy foil/strip and where higher strength and stiffness-per-thickness are needed. | 580 | 650 | 6 | 24 HRC | 5 % IACS |
Cold drawn | Choose for drawn wire (electrodes, getters, filaments) needing high strength and straightness. | 620 | 700 | 5 | 26 HRC | 4.9 % IACS |
What is Hafnium Hf-1 (R02001) Annealed?
Hafnium Hf-1 (R02001) Annealed is Hafnium Hf-1 (R02001) in the Annealed temper — standard stocked condition: maximum ductility for forming, machining and welding. Hafnium Hf-1 (R02001) Annealed has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 76% of refractory metal grades. Elongation at break is 25% and the elastic modulus is 138 GPa (20 Msi). Hafnium Hf-1 (R02001) Annealed has a density of 13.31 g/cm³ (0.481 lb/in³), heavier than 77% of refractory metal grades. It melts at 2,200°C (3,992 °F).
Limitations
- Heavy — 13.31 g/cm³ (0.481 lb/in³), worse than 77% of refractory metal grades
- Low strength — 240 MPa (34.8 ksi), worse than 76% of refractory metal grades
Hafnium Hf-1 (R02001) Annealed properties
Typical room-temperature values for Hafnium Hf-1 (R02001) Annealed; 10 are specific to this condition. Other listed values are Hafnium Hf-1 (R02001) reference data and may not represent this condition. Bars are the position among refractory metal grades.
Physical3
Hafnium Hf-1 (R02001) Annealed has a density of 13.31 g/cm³ (0.481 lb/in³), heavier than 77% of refractory metal grades. It melts at 2,200°C (3,992 °F).
Mechanical10
Hafnium Hf-1 (R02001) Annealed has a yield strength of 240 MPa (34.8 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 76% of refractory metal grades. Elongation at break is 25% and the elastic modulus is 138 GPa (20 Msi).
Thermal6
Hafnium Hf-1 (R02001) Annealed is rated for continuous service to 500°C (932 °F). It conducts heat at 23 W/m·K (13.3 BTU/hr·ft·°F), worse than 61% of refractory metal grades. Thermal expansion is 6 µm/m·K (3.33 µin/in·°F).
Electrical3
Hafnium Hf-1 (R02001) Annealed conducts electricity at 5.2 % IACS, worse than 55% of refractory metal grades.
Chemical & Environmental2
Corrosion resistance is excellent (85/100), better than 52% of refractory metal grades.
Manufacturability8
Hafnium Hf-1 (R02001) Annealed's machinability is poor (30/100, better than 54% of refractory metal grades); weldability good (60/100); formability good (65/100).
Common Calculations5
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with Hafnium Hf-1 (R02001) Annealed
Is Hafnium Hf-1 (R02001) easy to machine?
Machine like zirconium: sharp positive-rake tools, slow-to-moderate speeds with heavy feed, flood coolant to avoid galling, and collect chips/fines wet — dry swarf is pyrophoric.
Can Hafnium Hf-1 (R02001) be welded?
GTAW/EBW/laser only with full inert-gas trailing shields or a vacuum/glovebox; any O, N or H pickup embrittles the weld, and cleanliness must be surgical.
Can Hafnium Hf-1 (R02001) be formed, bent or molded?
Cold forms and rolls to foil with generous bend radii (hcp texture gives anisotropy and springback); hot work 700–1000 °C with protection or canning for heavy reductions.
What surface finishes work on Hafnium Hf-1 (R02001)?
Pickle in HNO3–HF mixtures to remove oxide/alpha case, then passivate in nitric; the natural oxide is protective, so plating and painting are rarely used and anodic colouring is only decorative.
Hafnium Hf-1 (R02001) 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 |
|---|---|---|
| Zrresidual zirconium allowed in commercial grade R02001 (nuclear grades restrict Zr and B) | ≤ 4.5 | 2.5 |
| Omax, ppm-level control governs strength/ductility | ≤ 0.13 | 0.08 |
| Fe | ≤ 0.05 | — |
| C | ≤ 0.02 | — |
| N | ≤ 0.01 | — |
| H | ≤ 0 | — |
| Al | ≤ 0.01 | — |
| Cr | ≤ 0.01 | — |
| Nb | ≤ 0.01 | — |
| Ti | ≤ 0.01 | — |
| W | ≤ 0.01 | — |
| Umax (3 ppm) | ≤ 3×10⁻⁴ | — |
| Hfbalance; Hf+Zr essentially 100 % less impurities | balance | — |
Hafnium Hf-1 (R02001) Annealed — frequently asked
What is Hafnium Hf-1 (R02001) Annealed used for?
Hafnium Hf-1 (R02001) Annealed is typically used for plasma cutting electrode tips, superalloy additive for turbine blades, chemical process equipment, capacitor dielectric films and high-temperature coatings. In short: standard commercial-purity hafnium; plasma cutting electrode metal; non-nuclear-purity grade.
What is the yield strength of Hafnium Hf-1 (R02001) Annealed?
Hafnium Hf-1 (R02001) Annealed has a typical yield strength of 240 MPa (34.8 ksi) and a tensile strength of 450 MPa (65.3 ksi) — weaker than 76% of refractory metal grades. Strength varies by condition: see the 6 listed tempers.
Is Hafnium Hf-1 (R02001) Annealed easy to machine?
Not especially — machinability is rated poor (30/100, better than 54% of refractory metal grades). Machine like zirconium: sharp positive-rake tools, slow-to-moderate speeds with heavy feed, flood coolant to avoid galling, and collect chips/fines wet — dry swarf is pyrophoric.
Can Hafnium Hf-1 (R02001) Annealed be welded?
Yes — weldability is rated good (60/100). GTAW/EBW/laser only with full inert-gas trailing shields or a vacuum/glovebox; any O, N or H pickup embrittles the weld, and cleanliness must be surgical.
What surface finishes work on Hafnium Hf-1 (R02001) Annealed?
Pickle in HNO3–HF mixtures to remove oxide/alpha case, then passivate in nitric; the natural oxide is protective, so plating and painting are rarely used and anodic colouring is only decorative.
Can Hafnium Hf-1 (R02001) Annealed be formed, bent or molded?
Cold forms and rolls to foil with generous bend radii (hcp texture gives anisotropy and springback); hot work 700–1000 °C with protection or canning for heavy reductions.
What is the maximum service temperature of Hafnium Hf-1 (R02001) Annealed?
Hafnium Hf-1 (R02001) Annealed is rated for continuous use to about 500°C (932 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between Hafnium Hf-1 (R02001) Annealed and Hafnium Hf-1 (R02001)-CD?
Annealed is the default condition — standard stocked condition: maximum ductility for forming, machining and welding. CD: choose for drawn wire (electrodes, getters, filaments) needing high strength and straightness. Yield strength is 240 MPa in Annealed versus 620 MPa in CD.
Sources
- ASTM B776 — Hafnium and Hafnium Alloy Strip, Sheet, Plate and Foil — ASTM International (2021)
- ASTM B777 — Hafnium and Hafnium Alloy Bar, Rod and Wire — ASTM International (2021)
- ATI Hafnium technical data sheet — ATI (Allegheny Technologies / Wah Chang) (2020)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (refractory & reactive metals) — ASM International (1990)
- CRC Handbook of Chemistry and Physics — physical properties of hafnium — CRC Press (2020)
- ASM Handbook Vol. 13B — Corrosion: Materials (zirconium and hafnium) — ASM International (2005)
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.