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The Mystery Metal Behind the Machines: DOMADIA™ Dilaton 46 – UNS K94600
A top-tier electronics manufacturer received a call from an aerospace client — their vacuum diodes kept failing mid-orbit due to unseen micro fractures. The cause? A mismatch in thermal expansion between glass seals and their metal counterparts. The fix? DOMADIA™ Dilaton 46 aka Nickel Iron Glass Sealing Alloy 46, also known as UNS K94600 FeNi46.
This alloy wasn’t just a patch — it was a revolution. Behind that solution was a quietly powerful metal: FeNi46, also known as UNS K94600 / DIN 1.3920.
Let’s break down the science, the specs, and the secrets behind the alloy trusted to hold the future together.
What is DOMADIA™ Dilaton 46 (FeNi46)?
DOMADIA™ Dilaton 46 is a precision-engineered iron-nickel alloy containing approximately 46% nickel, carefully designed for controlled thermal expansion. Its standout feature? A thermal expansion coefficient that matches glass and ceramics, making it essential in electronics and sealing applications.
Chemical Composition:
Element | Typical Range (%) |
Iron (Fe) | Balance |
Nickel (Ni) | ~46.0 |
Carbon (C) | ≤ 0.05 |
Manganese (Mn) | ≤ 0.60 |
Silicon (Si) | ≤ 0.30 |
Chromium (Cr) | ≤ 0.25 |
Other Elements | Trace |
Technical Specifications
- UNS K94600 F30
- DIN 1.3920
- Applicable Standards: SEW 385 / DIN 17745 / ASTM F30
- Thermal Expansion (30–300°C): ~6.5 x 10⁻⁶ /°C
- Density: ~8.1 g/cm³
- Curie Temperature: ~230°C
- Electrical Resistivity: ~49 µΩ·cm
- Magnetic Permeability: High
Key Applications

Electronic Glass-to-Metal Sealing
The most critical application: glass sealing in electronic components. FeNi46’s matched thermal expansion ensures crack-free bonds with glass, ideal for:
- Vacuum tubes
- Integrated circuit headers
- X-ray tube components
- hermetic packages including automotive and industrial lamps
Vacuum Sealing Technology
In high-vacuum systems like electron tubes and diodes, DOMADIA™ Dilaton 46 is used for vacuum-tight sealing structures, helping maintain integrity under extreme pressure differentials.
Magnetic Components & Transformers
Its ferromagnetic properties make it perfect for:
- Magnetic recording heads
- Magnetic shielding
- Specialized transformers
Corrosion-Resistant Coatings
When alloyed into intermetallics, DOMADIA™ Dilaton 46 contributes to high-temperature corrosion-resistant coatings — especially for jet engine turbine blades.
Available Forms
DOMADIA™ Dilaton 46 can be supplied in multiple precise geometries, including:

Standards & Certifications
DOMADIA™ Dilaton 46 complies with industry standards across global markets:
- SEW 385
- DIN 17745
- ASTM F30
This ensures reliability for critical applications where performance can’t be compromised.
Why It Matters — And Where It’s Going
The FeNi46 alloy isn’t flashy — it doesn’t sparkle or shine. But it does something far more important: it expands at just the right rate to protect your technology. From aerospace to quantum electronics, this alloy has earned its place in the hall of engineering fame.
And now, DOMADIA™ Dilaton 46 makes that science accessible, standard-compliant, and form-ready for your exact needs.
Final Thought
If your product depends on precision thermal compatibility, magnetic performance, or vacuum-tight integrity, DOMADIA™ Dilaton 46 might be the most important material you never knew you needed.
Looking for foils? Sheets? Vacuum seal-ready rods?
👉 Contact us now to explore custom solutions for your tech.
Visit our website on https://domadia.net/
Talk to us: Kairav Domadia | Aadil Domadia | Er.Pankaj Domadia | Pragati Sanap | Pooja N N | Shivani Kanojia