4j42 iron-nickel fixed expansion alloy is a series of fixed expansion alloys that can be matched with soft glass and ceramics with different expansion coefficients in a given temperature range by adjusting the nickel content. Its expansion coefficient and Curie point increase with the increase of nickel content. . This alloy is a widely used sealing structure material in the electric vacuum industry.
4J42 application overview and special requirements:
4J42 is a typical grade of glass-sealed alloy. It has been used for a long time in aviation factories and has stable performance.
4J42 alloy is mainly used for sealing with soft glass, ceramics, etc., to make leads, frames and sealing plugs for electronic tubes, transistors and integrated circuits.
In the application, the selected sealing material should match the expansion coefficient of the alloy. The grain size should be controlled during heat treatment to ensure that the material has good deep drawing properties. When using forged and rolled materials, the air tightness of the materials should be strictly inspected.
Similar Grade:
Russia U.S. U.K. Japan France Germany
42H Glass Sealing42
Uniseal42 Nilo42
Invar D
NSD N42 Vacodil 42
Nilo42
C Mn Si P S Al Co Ni Fe
≤
0.05 0.80 0.30 0.020 0.020 0.10 - 41.5~42.5 margin
4J42 physical and chemical properties:
4J42 melting temperature: 1430ºC.
Thermal conductivity of 4J42: λ=14.6W/(m·ºC).
4J42 specific heat capacity: 502J/(kg•ºC).
4J42 density: ρ=8.12g/cm3.
4J42 electrical properties: resistivity ρ=0.61μΩ·m.
4J42 Curie point: Tc=360ºC.
4J42 chemical properties The alloy has good corrosion resistance in the atmosphere, fresh water and sea water.
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