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​1.Definition of invar

Invar alloy---National standard called expansion alloy, is a kind of nickel and iron that contains 36% of nickel,63.8% of iron and 0.2% of carbon, its low thermal expansion coefficient, can keep fixed length in wide temperature range.


2. Basic properties

Invar alloy belongs to high nickel alloy base on iron, usually containing 32% - 36% Ni, also contains small elements of S, P, C and others, the rest of 60% invar alloy has the following properties:

a.Small expansion coefficient

b.Strength, hardness is not high

c.Low thermal conductivity

d.High plasticity and toughness


3.physical characteristics

The majority of metals or gold are both in expands when heated , but due to the ferromagnetic of invar alloy, its expansion coefficient is extremely low in a certain temperature range, sometimes even to zero or negative.


4.chemical characteristics

This alloy in magnetic temperature near the Curie point significantly reduce the thermal expansion coefficient, the so-called abnormal thermal expansion occurs abnormal (negative), which can be obtained the coefficient of expansion of very small or close to zeroa in wide range of temperatures near room temperature, the composition of this alloy is 64% of Fe and 36% of Ni and appear face-centered cubic structure, its grade is 4j36.


5.Production application

Is mainly used to manufacture gauge, thermometer, range finder, clock and watch escapement, gauge block, the resonant cavity of microwave equipment, gravimeter components, thermal bimetal component materials, optical instrument parts, etc.

Name FeNi36 alloy 4j36 Invar 0.05-3mm nickel iron alloy strip foil sheet
Standard ASTM B906
Certification IOS9001:2015,ISO/TS 16949:2009
Wall thickness 0.05-3.0mm
width 5.0-420mm
Grade 4J29 4j36 4J42 4J50 Invar36 FeNi36
Delivery time Within 25 days after receiving deposit
Payment term T/T,L/C
Supply ability 80tons per month
Packing Export standard package with polywood case or ISPM 15 stamped wooden case
Application: 4J36 is a special low expansion iron-nickel alloy with ultra-low expansion coefficient. The control of carbon and manganese components is very important. Cold deformation can reduce the coefficient of thermal expansion, and heat treatment in a specific temperature range can stabilize the coefficient of thermal expansion. Low expansion alloy 4J36 has a low expansion coefficient and good plasticity within the atmospheric temperature variation of -60-80 degrees, which is used to make components with a size close to constant within the temperature variation range, widely used in radio, precision instrument, instrument and other industries, making standard measuring tools, microwave resonant cavity, bimetallic wave layer and other application scope: thermostat, 5G filter, OLED screen, LNG ship