Refractory Metal TZM
UNS R03640, R03630 · ASTM B387 Grade 363 · also Mo-Ti-Zr
TZM is a molybdenum alloy with titanium, zirconium and carbon additions (ASTM B387 Grade 363, UNS R03630) whose fine carbides raise the recrystallization temperature and creep resistance.
Reference datasheet — TZM 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 Stress Relieved condition
TZM tempers and conditions
TZM is supplied in 5 conditions, soft to hard. Stress Relieved is the default FabDigit quotes; the values on this page are for it.
Compare all 5 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
powder-metallurgy blank, unworked | Pressed-and-sintered blank before forging/rolling; residual porosity means low strength and ductility — normally an intermediate product, occasionally sold for crucibles and furnace parts. | 350 | 450 | 4 | 170 HB | 27 % IACS |
fully recrystallized in vacuum | Choose when maximum dimensional stability and creep resistance above 1400 °C matter more than room-temperature strength; more brittle at RT because DBTT rises. | 420 | 560 | 25 | 12 HRC | 126 W/m·K |
vacuum arc cast and wrought-worked billet | Vacuum-arc-cast route giving very low interstitial content and coarse grain — preferred for large forged dies and high-temperature creep parts. | 560 | 700 | 18 | 20 HRC | 32 % IACS |
Stress RelievedDefault wrought, stress relieved below recrystallization | Standard stocked condition for rod, plate and forgings — best combination of room-temperature strength, ductility and dimensional stability up to ~1300 °C. | 760 | 900 | 15 | 26 HRC | 118 W/m·K |
as-swaged / as-rolled, unrecrystallized | Highest room-temperature strength and hardness (thin sheet, wire, small rod); limited ductility and residual stress, not for service above ~1000 °C. | 940 | 1,050 | 8 | 31 HRC | 29 % IACS |
What is TZM?
TZM is a molybdenum alloy with titanium, zirconium and carbon additions (ASTM B387 Grade 363, UNS R03630) whose fine carbides raise the recrystallization temperature and creep resistance. It provides 760 MPa yield, 900 MPa tensile and 15 % elongation at room temperature, retains strength above 1000 °C and is used to about 1300 °C in plate, bar, forgings and arc-cast or sintered stock. It oxidizes rapidly in air, so vacuum, inert gas or a silicide coating is required; fusion welding recrystallizes and embrittles joints, and cost is high. Pure Mo is the cheaper choice when hot strength is not critical. TZM has a density of 10.22 g/cm³ (0.369 lb/in³), heavier than 68% of refractory metal grades. It melts at 2,617°C (4,743 °F). TZM 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).
What is TZM 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
- X-ray rotating anode substrates
- Sintering furnace boats and support rails
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 83% 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 78% of refractory metal grades
Limitations
- Needs corrosion protection — 45/100, worse than 86% of refractory metal grades
- Difficult to weld — 20/100, worse than 79% of refractory metal grades
TZM properties
Typical room-temperature values for TZM-Stress Relieved; bars are the position among refractory metal grades.
Physical3
TZM has a density of 10.22 g/cm³ (0.369 lb/in³), heavier than 68% of refractory metal grades. It melts at 2,617°C (4,743 °F).
Mechanical16
TZM 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 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 conducts electricity at 30 % IACS, better than 83% of refractory metal grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 86% of refractory metal grades.
Sustainability4
Producing a kilogram of TZM takes about 380 MJ of energy and emits 26 kg of CO₂ — less than 78% of refractory metal grades. Typical recycled content is 25%.
Manufacturability7
TZM'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.
Strength versus weight in the refractory metal family
Yield strength against density for every refractory metal grade FabDigit runs. TZM is highlighted; hover a dot for its name, or open the interactive family chart.
Working with TZM
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.
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 |
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.
Equivalent designations
Standards and trade names that resolve to Refractory Metal TZM in FabDigit's catalog. Equivalence is nominal — check the exact specification when certification matters.
- UNS
- R03640R03630
- ASTM
- B387 Grade 363
- Trade names
- Mo-Ti-Zr
How much does TZM cost?
TZM is a specialty-cost refractory metal ($$$$$), pricier than about 100% 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.
TZM — frequently asked
What is TZM used for?
TZM 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?
TZM 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 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 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?
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 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?
TZM 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.
How much does TZM cost?
TZM is a specialty-cost refractory metal ($$$$$), pricier than about 100% 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
- 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; 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.