Titanium IMI 829
IMI 829 is a high-temperature near-alpha titanium alloy developed for better creep and oxidation resistance than IMI 685 in jet engine discs and blades.
Reference datasheet — IMI 829 is not in the instant-quote catalog. Upload your part and an engineer will quote it in this grade or suggest the closest stocked equivalent.
Values for the BETA-STA condition
IMI 829 tempers and conditions
IMI 829 is supplied in 3 conditions, soft to hard. BETA-STA is the default FabDigit quotes; the values on this page are for it.
Compare all 3 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
Annealed | Supply condition for forging stock and semi-finished bar before final beta solution treatment and ageing. | 820 | 930 | 13 | 31 HRC | 1.1 % IACS |
BETA-STADefault beta solution treated (≈1050 °C, air/oil cool) and aged ≈625 °C | Standard rotating-grade condition for discs, blades and rings; best creep and oxidation performance to ~580 °C. | 865 | 980 | 11 | 33 HRC | 1.1 % IACS |
Α+β STA | Finer, more equiaxed structure for parts needing better low-cycle fatigue and room-temperature ductility at some loss of creep strength. | 890 | 1,000 | 13 | 34 HRC | 1.1 % IACS |
What is IMI 829?
IMI 829 is a high-temperature near-alpha titanium alloy developed for better creep and oxidation resistance than IMI 685 in jet engine discs and blades. Beta-STA material provides 865 MPa yield, 980 MPa tensile, 11% elongation and service to 580 °C, and is supplied as forged discs, rings and blade stock in BETA-STA, alpha-beta STA and annealed conditions. Machinability is very low (15), weld ductility stays below base metal, and processing is hot-work only. IMI 834 is the step up for roughly 600 °C duty, with IMI 685 as the lower-temperature predecessor. IMI 829 has a density of 4.54 g/cm³ (0.164 lb/in³), heavier than 80% of titanium grades. It melts at 1,550°C (2,822 °F). IMI 829 has a yield strength of 865 MPa (125 ksi) and a tensile strength of 980 MPa (142 ksi) — stronger than 74% of titanium grades. Elongation at break is 11% and the elastic modulus is 120 GPa (17.4 Msi).
What is IMI 829 used for?
- Turbine engine discs
- Compressor blades
- HP compressor disc and drum forgings
- Engine rings and spacers
- Static hot-section brackets
- Blade and vane roots
- Shaft and spool forgings
Advantages
- High service temperature — 580°C (1,076 °F), better than 99% of titanium grades
- Stiff — 120 GPa (17.4 Msi), better than 98% of titanium grades
Limitations
- Difficult to weld — 45/100, worse than 92% of titanium grades
- Limited ductility — 11%, worse than 87% of titanium grades
- Limited formability — 20/100, worse than 83% of titanium grades
IMI 829 properties
Typical room-temperature values for IMI 829-BETA-STA; bars are the position among titanium grades.
Physical3
IMI 829 has a density of 4.54 g/cm³ (0.164 lb/in³), heavier than 80% of titanium grades. It melts at 1,550°C (2,822 °F).
Mechanical16
IMI 829 has a yield strength of 865 MPa (125 ksi) and a tensile strength of 980 MPa (142 ksi) — stronger than 74% of titanium grades. Elongation at break is 11% and the elastic modulus is 120 GPa (17.4 Msi).
Thermal6
IMI 829 is rated for continuous service to 580°C (1,076 °F). It conducts heat at 7 W/m·K (4.04 BTU/hr·ft·°F), worse than 76% of titanium grades. Thermal expansion is 9.5 µm/m·K (5.28 µin/in·°F).
Electrical3
IMI 829 conducts electricity at 1.1 % IACS, worse than 67% of titanium grades.
Chemical & Environmental3
Corrosion resistance is excellent (85/100), worse than 93% of titanium grades.
Sustainability4
Producing a kilogram of IMI 829 takes about 700 MJ of energy and emits 43 kg of CO₂ — more than 74% of titanium grades. Typical recycled content is 15%.
Manufacturability8
IMI 829's machinability is poor (15/100, worse than 97% of titanium grades); weldability fair (45/100); formability poor (20/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Strength versus weight in the titanium family
Yield strength against density for every titanium grade FabDigit runs. IMI 829 is highlighted; hover a dot for its name, or open the interactive family chart.
Working with IMI 829
Is IMI 829 easy to machine?
Machine like a high-strength near-alpha Ti: rigid setup, sharp uncoated-carbide or coated carbide, 20–35 m/min turning, heavy flood coolant, positive rake and no dwell to avoid work hardening and fire risk from fine chips.
Can IMI 829 be welded?
GTAW/EBW in high-purity argon or vacuum with full trailing-gas or chamber protection; post-weld stress relief/age at ~600–625 °C is required and weld ductility remains lower than base metal — avoid welds in rotating parts.
Can IMI 829 be formed, bent or molded?
Hot work only: forge/ring-roll in the 950–1050 °C range with controlled final beta reduction; cold forming is impractical, sheet work needs hot sizing or creep forming.
IMI 829 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 |
|---|---|---|
| Alalpha stabiliser | 5 – 6.1 | 5.5 |
| Sn | 3 – 4 | 3.5 |
| Zr | 2.5 – 3.5 | 3 |
| Nbimproves oxidation resistance | 0.7 – 1.3 | 1 |
| Mo | 0.2 – 0.4 | 0.3 |
| Sisilicide precipitation for creep resistance | 0.2 – 0.4 | 0.3 |
| C | ≤ 0.08 | |
| Fe | ≤ 0.2 | |
| Omax, kept low for creep/toughness | ≤ 0.15 | 0.1 |
| N | ≤ 0.05 | |
| H | ≤ 0.01 | |
| Ti | balance |
What surface finishes work on IMI 829?
Grit blast plus pickling to remove alpha case after hot working; shot peening for fatigue, and anodic/chemical oxide or Ti-N type coatings where galling protection is needed.
Surface treatments FabDigit runs on titanium parts — pick them in the quote configurator or call them out on the drawing. Each links to its datasheet in the surface-finish library (thickness, specs, call-out, material verdicts).
Thermal Spray
How much does IMI 829 cost?
IMI 829 is a high-cost titanium ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
IMI 829 — frequently asked
What is IMI 829 used for?
IMI 829 is typically used for turbine engine discs, compressor blades, HP compressor disc and drum forgings, engine rings and spacers, static hot-section brackets and blade and vane roots. In short: 580 °C creep capability; higher-temperature IMI 685 successor; hot-section rotating disc alloy.
What is the yield strength of IMI 829?
IMI 829 has a typical yield strength of 865 MPa (125 ksi) and a tensile strength of 980 MPa (142 ksi) — stronger than 74% of titanium grades. Strength varies by condition: see the 3 listed tempers.
Is IMI 829 easy to machine?
Not especially — machinability is rated poor (15/100, worse than 97% of titanium grades). Machine like a high-strength near-alpha Ti: rigid setup, sharp uncoated-carbide or coated carbide, 20–35 m/min turning, heavy flood coolant, positive rake and no dwell to avoid work hardening and fire risk from fine chips.
Can IMI 829 be welded?
With care — weldability is rated fair (45/100). GTAW/EBW in high-purity argon or vacuum with full trailing-gas or chamber protection; post-weld stress relief/age at ~600–625 °C is required and weld ductility remains lower than base metal — avoid welds in rotating parts.
What surface finishes work on IMI 829?
Grit blast plus pickling to remove alpha case after hot working; shot peening for fatigue, and anodic/chemical oxide or Ti-N type coatings where galling protection is needed.
Can IMI 829 be formed, bent or molded?
Hot work only: forge/ring-roll in the 950–1050 °C range with controlled final beta reduction; cold forming is impractical, sheet work needs hot sizing or creep forming.
What is the maximum service temperature of IMI 829?
IMI 829 is rated for continuous use to about 580°C (1,076 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between IMI 829 BETA-STA and IMI 829-ANN?
BETA-STA is the default condition — standard rotating-grade condition for discs, blades and rings; best creep and oxidation performance to ~580 °C. ANN: supply condition for forging stock and semi-finished bar before final beta solution treatment and ageing. Yield strength is 865 MPa in BETA-STA versus 820 MPa in ANN.
How much does IMI 829 cost?
IMI 829 is a high-cost titanium ($$$$), pricier than about 78% of the materials FabDigit quotes. Part price depends far more on geometry, tolerance and quantity than on the raw stock — upload a CAD file for a live quote.
Sources
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (titanium alloys) — ASM International (1990)
- Materials Properties Handbook: Titanium Alloys — ASM International (1994)
- IMI Titanium high-temperature alloy data (IMI 685 / IMI 829 / IMI 834 family) — IMI Titanium / TIMET UK (1990)
- Titanium and Titanium Alloys — Fundamentals and Applications (Leyens & Peters) — Wiley-VCH (2003)
Property data is compiled from published supplier and standards handbooks and normalised for comparison; hardness values on non-Brinell scales are converted approximately for charting only. Manufacturability limits are FabDigit quote-engine defaults and may be relaxed by engineering review. Nothing on this page is a certification — request mill certs, CoC or material test reports with your order.