4J52 Hermetic Sealing Tube CTE 7.6*10^(-6)/°C AS9100 Compliant

Alloy 52 Hermetic Sealing Tube (Vacodil 52) | CTE 9.9×10^(-6)/°C | AS9100 Compliant | Glass-to-Metal Seals | Aerospace & Medical Grade

Technical Specifications

Property Value Standard

Composition Ni 51.5±0.3%, Cr 0.15±0.05%, Mn 0.8%, Si 0.15%, Bal. Fe ASTM F30

CTE (20-450°C) 9.9±0.2x10^(-6)/K ASTM E228

Glass Matching Range 8.8-10.5×10^(-6)/K (DW-30 to Corning 7052) ISO 3585

Sealing Temperature 850-1000°C (H2 atmosphere) MIL-STD-889

Leak Rate Performance <1×10^(-11) mbar·L/s (He) ASTM E493

Global Standards Compliance

Region Standard Designation

Aerospace AS9100 Rev. D -

USA ASTM F30 UNS K94610

Europe EN 10305-4 FeNi52

Medical ISO 13485 -

Vacuum ASTM E493 Hermetic Seals

Material Characteristics

Thermal Expansion Control:

• Precise CTE tuning through nickel content (48-53% Ni)
• Curie point increases linearly with Ni% (400-520°C range)
• Minimal thermal hysteresis during thermal cycling

Microstructural Requirements:

• Grain size: ASTM 7-8 (30-50μm) for optimal deep-drawing
• Inclusion rating: ASTM E45 ≤1.0 (Type A & B)
• Surface oxide control: <0.5μm thickness

Glass Matching Guide

Glass Type CTE (×10^(-6)/°C) Matched Alloy 52 Variant

Corning 7052 (Borosilicate) 4.6 Ni 52% (Standard)

Schott 8250 9.9 Ni 51.5%

DW-30 (Tungsten Seal) 10.5 Ni 53%

Alumina Ceramic (96%) 6.8 Ni 50% + Cu modifier

Normal composition%

Typical Physical properties

Coefficient of expansion

Grain size of Alloy52
The grain size of the alloy deep-drawing belt should not be less than level 7, and the grain size less than level 7 should not exceed 10% of the area. When the average grain size of the strip with a thickness of less than 0.13mm is estimated, the number of grains along the thickness of the strip should be no less than 8.

Welding performance of Alloy52
The combined gold has good welding performance and can be brazed and spot welded. The combination of gold and soft glass should be pre-oxidized before sealing.

Coefficient of Expansion