Refractory Metal TZM · heat-treated state · default condition
Refractory Metal TZM Stress Relieved
Properties of the Stress Relieved condition, compared with the other TZM tempers.
Standard stocked condition for rod, plate and forgings — best combination of room-temperature strength, ductility and dimensional stability up to ~1300 °C.
What is TZM Stress Relieved?
TZM Stress Relieved is TZM heat treated to Stress Relieved — standard stocked condition for rod, plate and forgings — best combination of room-temperature strength, ductility and dimensional stability up to ~1300 °C. TZM Stress Relieved has a yield strength of 760 MPa (110 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 88% of refractory metal grades. Elongation at break is 15% and the elastic modulus is 315 GPa (45.7 Msi). TZM Stress Relieved has a density of 10.22 g/cm³ (0.369 lb/in³), heavier than 67% of refractory metal grades. It melts at 2,617°C (4,743 °F).
Advantages
- Easy to machine — 45/100, better than 99% of refractory metal grades
- High strength — 760 MPa (110 ksi), better than 88% of refractory metal grades
- High electrical conductivity — 30 % IACS, better than 84% of refractory metal grades
- Conducts heat well — 118 W/m·K (68.2 BTU/hr·ft·°F), better than 81% of refractory metal grades
- Stiff — 315 GPa (45.7 Msi), better than 76% of refractory metal grades
Limitations
- Needs corrosion protection — 45/100, worse than 87% of refractory metal grades
- Difficult to weld — 20/100, worse than 79% of refractory metal grades
TZM Stress Relieved properties
Typical room-temperature values for TZM Stress Relieved — 11 properties are specific to this condition; the rest are grade-level values shared by every TZM temper. Each bar shows where the value sits among the refractory metal grades in FabDigit's library — further right is higher.
Physical3
TZM Stress Relieved has a density of 10.22 g/cm³ (0.369 lb/in³), heavier than 67% of refractory metal grades. It melts at 2,617°C (4,743 °F).
Mechanical16
TZM Stress Relieved has a yield strength of 760 MPa (110 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 88% of refractory metal grades. Elongation at break is 15% and the elastic modulus is 315 GPa (45.7 Msi).
Thermal6
TZM Stress Relieved is rated for continuous service to 1,300°C (2,372 °F). It conducts heat at 118 W/m·K (68.2 BTU/hr·ft·°F), better than 81% of refractory metal grades. Thermal expansion is 5.3 µm/m·K (2.94 µin/in·°F).
Electrical3
TZM Stress Relieved conducts electricity at 30 % IACS, better than 84% of refractory metal grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 87% of refractory metal grades.
Sustainability4
Producing a kilogram of TZM Stress Relieved takes about 380 MJ of energy and emits 26 kg of CO₂ — less than 77% of refractory metal grades. Typical recycled content is 25%.
Manufacturability7
TZM Stress Relieved's machinability is fair (45/100, better than 99% of refractory metal grades); weldability poor (20/100); formability poor (25/100).
Common Calculations5
Values are nominal handbook figures for design screening. Certified mill or lot data ships with every FabDigit order on request.
Other TZM tempers and conditions
TZM is also supplied in 4 other conditions. The full side-by-side table is on the TZM overview.
- Stress RelievedDefaultStandard stocked condition for rod, plate and forgings — best combination of room-temperature strength, ductility and dimensional stability up to ~1300 °C.760 MPa yield · 26 HRC
- Cold WorkedHighest room-temperature strength and hardness (thin sheet, wire, small rod); limited ductility and residual stress, not for service above ~1000 °C.940 MPa yield · 31 HRC
- Vacuum AnnealedChoose when maximum dimensional stability and creep resistance above 1400 °C matter more than room-temperature strength; more brittle at RT because DBTT rises.420 MPa yield · 12 HRC
Working with TZM Stress Relieved
Is TZM easy to machine?
Machines like a hard, abrasive cast iron — sharp positive-rake carbide or PCD tools, rigid setup, generous coolant, avoid dull edges that cause chipping and subsurface cracks; grinding and EDM work well.
Can TZM be welded?
Fusion welding (EB, laser, GTAW in chamber) recrystallizes and embrittles the joint — prefer vacuum brazing, mechanical fastening or friction/diffusion bonding for structural parts.
Can TZM be formed, bent or molded?
Form warm (200–500 °C, higher for recrystallized stock) to stay above the DBTT; generous bend radii, no sharp cold bends, and stress relieve at 900–1100 °C after heavy work.
What surface finishes work on TZM?
Cannot be anodized; use electropolishing or mechanical polish for clean vacuum surfaces and Si-Cr-Fe silicide, aluminide or CVD coatings when the part must see air above ~500 °C.
TZM 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 |
|---|---|---|
| Ticarbide former, main strengthener | 0.4 – 0.55 | 0.5 |
| Zr | 0.06 – 0.12 | 0.08 |
| Cforms TiC/ZrC dispersoids | 0.01 – 0.04 | 0.03 |
| O | ≤ 0.03 | — |
| N | ≤ 0 | — |
| Fe | ≤ 0.01 | — |
| Ni | ≤ 0.01 | — |
| Si | ≤ 0.01 | — |
| Mobalance, ≥99.2 % with additions | balance | — |
TZM Stress Relieved — frequently asked
What is TZM Stress Relieved used for?
TZM Stress Relieved is typically used for rocket nozzles and thrust chamber inserts, hot-work extrusion and forging dies, furnace hot-zone structures and fixtures, die-casting core pins and shot sleeves, isothermal forging tooling and X-ray rotating anode substrates. In short: higher-strength molybdenum alloy.
What is the yield strength of TZM Stress Relieved?
TZM Stress Relieved has a typical yield strength of 760 MPa (110 ksi) and a tensile strength of 900 MPa (131 ksi) — stronger than 88% of refractory metal grades. Strength varies by condition: see the 5 listed tempers.
Is TZM Stress Relieved easy to machine?
Reasonably — machinability is rated fair (45/100, better than 99% of refractory metal grades). Machines like a hard, abrasive cast iron — sharp positive-rake carbide or PCD tools, rigid setup, generous coolant, avoid dull edges that cause chipping and subsurface cracks; grinding and EDM work well.
Can TZM Stress Relieved be welded?
Not readily — weldability is rated poor (20/100). Fusion welding (EB, laser, GTAW in chamber) recrystallizes and embrittles the joint — prefer vacuum brazing, mechanical fastening or friction/diffusion bonding for structural parts.
What surface finishes work on TZM Stress Relieved?
Cannot be anodized; use electropolishing or mechanical polish for clean vacuum surfaces and Si-Cr-Fe silicide, aluminide or CVD coatings when the part must see air above ~500 °C.
Can TZM Stress Relieved be formed, bent or molded?
Form warm (200–500 °C, higher for recrystallized stock) to stay above the DBTT; generous bend radii, no sharp cold bends, and stress relieve at 900–1100 °C after heavy work.
What is the maximum service temperature of TZM Stress Relieved?
TZM Stress Relieved is rated for continuous use to about 1,300°C (2,372 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
Can FabDigit make parts in TZM Stress Relieved?
Yes — TZM Stress Relieved is available for CNC machining and sheet metal with instant online pricing. Upload a STEP file to get a price and a DFM check.
Sources
- ASTM B387 — Molybdenum and Molybdenum Alloy Bar, Rod, and Wire (Type 364 TZM) — ASTM International (2018)
- ASTM B386 — Molybdenum and Molybdenum Alloy Plate, Sheet, Strip, Foil — ASTM International (2018)
- TZM molybdenum alloy material properties — Plansee SE (2023)
- ASM Handbook Vol. 2 — Properties of Refractory Metals and Alloys — ASM International (1990)
- Molybdenum and TZM technical data — H.C. Starck Solutions / Ed Fagan Inc. (2022)
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.