4J50

Product Description:

4J50 is a series of constant expansion alloys that can match soft glasses and ceramics with different expansion coefficients within a given temperature range by adjusting the nickel content. Its expansion coefficient and Curie point increase with the increase in nickel content. This combination alloy is a sealing structural material widely used in the electric vacuum industry. 4J50 is a typical grade of glass-sealed alloy. It has been used in aviation factories for a long time and has stable performance.

Physical properties:

Melting point 1395-1425℃

Density ρ=8.21g/cm³

Resistivity ρ=0.44μΩ·m

Curie point Tc=500℃.

At 4000A/m, the residual magnetic induction intensity Br=1.03T, and the coercive force Hc=10A/m.

Extreme chemical composition:

characteristic:

The alloy has a low coefficient of thermal expansion, good thermal stability and high precision stability, allowing it to maintain stable size and shape under extreme temperatures. In addition, 4J50 iron-nickel fixed expansion alloy also has the advantages of corrosion resistance, high strength, good processability, etc., and can meet the requirements of various high-precision applications.

Application areas:

Used to make precision impedance diaphragms, wet reed and dry reed relays, precision length measurement, and sealing with corresponding soft glass. The selected sealing material should be matched to the expansion coefficient of the alloy in the application. The grain size should be controlled during heat treatment to ensure that the material has good deep drawing tensile properties. When using forged or rolled materials, the air tightness of the materials should be strictly inspected.

form:

Rod, plate, strip, wire, tube