Refractory Metal TZC-RX (Recrystallized)
Heat-treated state
Only used where full microstructural stability at very high service temperature outweighs the loss of room-temperature toughness (DBTT rises well above RT).
Values for the RX condition
Other TZC tempers and conditions
TZC is listed in 4 conditions; see the grade overview at TZC.
Compare all 4 conditionsHide
| Condition · open for datasheet | Best for | Yield MPa | Tensile MPa | Elong. % | Hardness | Conductivity |
|---|---|---|---|---|---|---|
RXThis page Recrystallized | Only used where full microstructural stability at very high service temperature outweighs the loss of room-temperature toughness (DBTT rises well above RT). | 560 | 700 | 4 | 20 HRC | 22 % IACS |
SRDefault Stress relieved | The standard stocked condition: retains most worked strength while removing residual stress for dimensional stability during machining and thermal cycling. | 930 | 1,050 | 8 | 30 HRC | 105 W/m·K |
As-welded deposit | Highest as-fabricated strength; pick for heavy sections where residual stress is acceptable and machining follows. | 1,030 | 1,150 | 6 | 32 HRC | 19.5 % IACS |
Cold worked | Small-diameter rod, wire and thin sheet delivered in the worked state for maximum strength and best low-temperature ductility. | 1,180 | 1,300 | 5 | 35 HRC | 19 % IACS |
What is TZC-RX?
TZC-RX is TZC heat treated to RX — only used where full microstructural stability at very high service temperature outweighs the loss of room-temperature toughness (DBTT rises well above RT). TZC-RX has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 78% of refractory metal grades. Elongation at break is 4% and the elastic modulus is 310 GPa (45 Msi). TZC-RX has a density of 10.05 g/cm³ (0.363 lb/in³), heavier than 60% of refractory metal grades. It melts at 2,590°C (4,694 °F). SR is the default condition FabDigit quotes; RX is available on request or by drawing note.
Advantages
- High service temperature — 1,700°C (3,092 °F), better than 90% of refractory metal grades
- Low embodied carbon — 15 kg CO₂/kg, better than 86% of refractory metal grades
- High electrical conductivity — 22 % IACS, better than 80% of refractory metal grades
- Conducts heat well — 110 W/m·K (63.6 BTU/hr·ft·°F), better than 79% of refractory metal grades
- High strength — 560 MPa (81.2 ksi), better than 78% of refractory metal grades
Limitations
- Limited formability — 8/100, worse than 90% of refractory metal grades
- Low fracture toughness — 12 MPa·√m (10.9 ksi·√in), worse than 87% of refractory metal grades
- Needs corrosion protection — 45/100, worse than 86% of refractory metal grades
- Limited ductility — 4%, worse than 84% of refractory metal grades
- Difficult to weld — 20/100, worse than 79% of refractory metal grades
TZC-RX properties
Typical room-temperature values for TZC-RX; 23 are specific to this condition. Other listed values are TZC reference data and may not represent this condition. Bars are the position among refractory metal grades.
Physical3
TZC-RX has a density of 10.05 g/cm³ (0.363 lb/in³), heavier than 60% of refractory metal grades. It melts at 2,590°C (4,694 °F).
Mechanical15
TZC-RX has a yield strength of 560 MPa (81.2 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 78% of refractory metal grades. Elongation at break is 4% and the elastic modulus is 310 GPa (45 Msi).
Thermal6
TZC-RX is rated for continuous service to 1,700°C (3,092 °F). It conducts heat at 110 W/m·K (63.6 BTU/hr·ft·°F), better than 79% of refractory metal grades. Thermal expansion is 5.3 µm/m·K (2.94 µin/in·°F).
Electrical3
TZC-RX conducts electricity at 22 % IACS, better than 80% of refractory metal grades.
Chemical & Environmental3
Corrosion resistance is fair (45/100), worse than 86% of refractory metal grades.
Sustainability4
Producing a kilogram of TZC-RX takes about 210 MJ of energy and emits 15 kg of CO₂ — less than 84% of refractory metal grades. Typical recycled content is 25%.
Manufacturability8
TZC-RX's machinability is fair (38/100, better than 90% of refractory metal grades); weldability poor (20/100); formability not recommended (8/100).
Values are nominal handbook figures for design screening. Confirm any required mill or lot documentation when quoting.
Working with TZC-RX
Is TZC easy to machine?
Use sharp, rigid setups with carbide or CBN tools, positive rake, generous coolant and light finishing passes; hard TiC/ZrC particles abrade edges and the alloy tends to chip rather than form continuous chips.
Can TZC be welded?
Fusion welding is not recommended — the heat-affected zone recrystallizes and grain-boundary embrittlement causes cracking; join by vacuum brazing, mechanical fastening or electron-beam welding with strict pre/post-heat.
Can TZC be formed, bent or molded?
Form only warm (typically 300–800 °C) with heated tooling; cold bending or blanking of thick sections cracks because the ductile–brittle transition is near room temperature.
What surface finishes work on TZC?
Grind or lap for tight tolerance, then apply silicide (MoSi₂), aluminide or Pt-group coating for air service above 500 °C; no anodizing route exists.
TZC 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 |
|---|---|---|
| Ti | 1 – 1.5 | 1.2 |
| Zr | 0.15 – 0.4 | 0.3 |
| Cforms TiC/ZrC strengthening dispersion | 0.1 – 0.25 | 0.15 |
| O | ≤ 0.03 | 0.01 |
| N | ≤ 0.01 | 0 |
| Fe | ≤ 0.01 | — |
| Ni | ≤ 0.01 | — |
| Si | ≤ 0.01 | — |
| Mo | balance | — |
TZC-RX — frequently asked
What is TZC-RX used for?
TZC-RX is typically used for hot-work forging dies, extrusion tooling for superalloys, rocket/aerospace hot-section parts and glass-forming molds. In short: stronger, more creep-resistant than TZM; highest-temperature Mo tooling alloy; not fusion weldable.
What is the yield strength of TZC-RX?
TZC-RX has a typical yield strength of 560 MPa (81.2 ksi) and a tensile strength of 700 MPa (102 ksi) — stronger than 78% of refractory metal grades. Strength varies by condition: see the 4 listed tempers.
Is TZC-RX easy to machine?
Not especially — machinability is rated fair (38/100, better than 90% of refractory metal grades). Use sharp, rigid setups with carbide or CBN tools, positive rake, generous coolant and light finishing passes; hard TiC/ZrC particles abrade edges and the alloy tends to chip rather than form continuous chips.
Can TZC-RX be welded?
Not readily — weldability is rated poor (20/100). Fusion welding is not recommended — the heat-affected zone recrystallizes and grain-boundary embrittlement causes cracking; join by vacuum brazing, mechanical fastening or electron-beam welding with strict pre/post-heat.
What surface finishes work on TZC-RX?
Grind or lap for tight tolerance, then apply silicide (MoSi₂), aluminide or Pt-group coating for air service above 500 °C; no anodizing route exists.
Can TZC-RX be formed, bent or molded?
Form only warm (typically 300–800 °C) with heated tooling; cold bending or blanking of thick sections cracks because the ductile–brittle transition is near room temperature.
What is the maximum service temperature of TZC-RX?
TZC-RX is rated for continuous use to about 1,700°C (3,092 °F). Strength falls off well before that limit — check the elevated-temperature data for load-bearing parts.
What is the difference between TZC-SR and TZC-RX?
SR is the default condition — the standard stocked condition: retains most worked strength while removing residual stress for dimensional stability during machining and thermal cycling. RX: only used where full microstructural stability at very high service temperature outweighs the loss of room-temperature toughness (DBTT rises well above RT). Yield strength is 930 MPa in SR versus 560 MPa in RX.
Sources
- ASTM B387 — Molybdenum and Molybdenum Alloy Bar, Rod, and Wire — ASTM International (2018)
- ASM Handbook Vol. 2 — Properties and Selection: Nonferrous Alloys and Special-Purpose Materials (refractory metals) — ASM International (1990)
- Molybdenum alloys (TZM/TZC/MHC) technical data — Plansee SE (2023)
- Refractory Metals and Alloys — mechanical and creep property compilations — International Molybdenum Association / TMS literature (2015)
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.