V-4-4values describe: V-4Cr-4Ti
Fusion, private
What it enables
The other low-activation road: vanadium alloys pair with liquid lithium blankets at temperatures RAFM steels cannot hold.
Status and pusher
Fabrication base and oxygen pickup remain the blockers; pushed by US and Japan fusion materials programs.
Watch out
Interstitial oxygen embrittlement governs every process step.
Properties
The values below are candidate: compiled from the sources named, not yet individually validated.
Provisional provenance: EUROfusion and international fusion materials programmes.
Wet cleaning
| Recipe | not established |
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| Forbidden | oxygen pickup during any hot wet process |
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| Limit | interstitial oxygen, which embrittles |
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Vacuum and outgassing
| Outgassing, unbaked (10 h) | insufficient data |
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| Outgassing, baked | insufficient data |
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| Vapour pressure | negligible |
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Temperature
| Bake, assembled | 450 °C |
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| Vacuum degas | 1000 °C |
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| Metallurgical limit | recrystallises ~1100 °C |
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Thermal
| CTE | 9.7 ppm/K |
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| Thermal conductivity | 31 W/m·K |
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| Specific heat | 490 J/kg·K |
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| Melting / softening | 1910 °C |
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Mechanical
| Strength | 300–400 ys MPa |
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| Elongation | 20 % |
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| Young's modulus | 128 GPa |
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| Density | 6.1 g/cm3 |
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Electrical and magnetic
| Relative permeability | ~1.0 |
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| Resistivity | 25 µΩ·cm |
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Engineering
| Process notes | low activation for fusion structures |
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| Availability and cost | research |
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Grades
| V-4Cr-4Ti | the reference heat chemistry |
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Sources · 1
- EUROfusion and international materials programs
← The Matter