Specifications
Brand Name :
TANKII
Model Number :
4J29
Certification :
ISO9001:2008
Place of Origin :
Shanghai, China
MOQ :
30kg
Price :
To negotiate
Supply Ability :
200+TON+MONTH
Delivery Time :
7-12 days
Packaging Details :
Spool, Coil, Carton,Wooden case with Plastic Film Accordin to custom's requirements
Payment Terms :
L/C, T/T, Western Union, MoneyGram
Material :
Iron Nickel Cobalt
Port :
Shanghai
Surface :
Silver, No oil
Shape :
Round/ Square Pipe Tube
Resistance :
Low
Grade :
Precision Alloy
Description

4j29 Kovar Iron Nickel Cobalt Alloy Pipe Low Resistance Square / Round Tube Pipe

General Description:

4J29, is a nickel-cobalt ferrous alloy compositionally identical to Fernico 1, designed to have substantially the same thermal expansion characteristics as borosilicate glass (~5 × 10−6 /K between 30 and 200 °C, to ~10 × 10−6 /K at 800 °C) in order to allow a tight mechanical joint between the two materials over a range of temperatures. It finds application in glass-to-metal seals in scientific apparatus, and conductors entering glass envelopes of electronic parts such as vacuum tubes (valves), X-ray and microwave tubes and some lightbulbs.

Kovar not only has thermal expansion similar to glass, but its nonlinear thermal expansion curve can often be made to match a glass, thus allowing the joint to tolerate a wide temperature range. Chemically, it bonds to glass via the intermediate oxide layer of nickel(II) oxide and cobalt(II) oxide; the proportion of iron oxide is low due to its reduction with cobalt. The bond strength is highly dependent on the oxide layer thickness and character. The presence of cobalt makes the oxide layer easier to melt and dissolve in the molten glass. A grey, grey-blue or grey-brown color indicates a good seal. A metallic color indicates lack of oxide, while black color indicates overly oxidized metal, in both cases leading to a weak joint.

4J29was invented to meet the need for a reliable glass-to-metal seal, which is required in electronic devices such as light bulbs, vacuum tubes, cathode ray tubes, and in vacuum systems in chemistry and other scientific research. Most metals cannot seal to glass because their coefficient of thermal expansion is not the same as glass, so as the joint cools after fabrication the stresses due to the differential expansion rates of the glass and metal cause the joint to crack.

Chemical Composition:

Fe Ni Co C Si Mn
balance 29% 17% < 0.01% 0.2% 0.3%

Main properties:

Property sintered HIPed
Density g /cm3 8.0 8.35
Hardness / HV1 160 150
Youngs Modulus / GPa 138 138
Reduction of area at fracture / % 30 30
Yield Strength / MPa 270 270
Thermal conductivity / W/K∙m 17
Curie temperature / °C 435
Electrical resistivity Ω mm2 / m 0.49
Specific heat J/g∙K 0.46
Thermal expansion coefficient/10−6 K−1 (25 – 200 °C) 5.5
(25–300 °C) 5.1
(25–400 °C) 4.9
(25–450 °C) 5.3
(25–500 °C) 6.2

Style of supply:

Alloys Name Type Dimension
4J29 Wire D= 0.1~8mm
4J29 Strip W= 5~250mm T= 0.1mm
4J29 Foil W= 10~100mm T= 0.01~0.1
4J29 Bar Dia= 8~100mm L= 50~1000

4j29 Kovar Iron Nickel Cobalt Alloy Pipe Low Resistance Square / Round Tube Pipe4j29 Kovar Iron Nickel Cobalt Alloy Pipe Low Resistance Square / Round Tube Pipe4j29 Kovar Iron Nickel Cobalt Alloy Pipe Low Resistance Square / Round Tube Pipe

4j29 Kovar Iron Nickel Cobalt Alloy Pipe Low Resistance Square / Round Tube Pipe

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4j29 Kovar Iron Nickel Cobalt Alloy Pipe Low Resistance Square / Round Tube Pipe

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Brand Name :
TANKII
Model Number :
4J29
Certification :
ISO9001:2008
Place of Origin :
Shanghai, China
MOQ :
30kg
Price :
To negotiate
Contact Supplier
4j29 Kovar Iron Nickel Cobalt Alloy Pipe Low Resistance Square / Round Tube Pipe
4j29 Kovar Iron Nickel Cobalt Alloy Pipe Low Resistance Square / Round Tube Pipe
4j29 Kovar Iron Nickel Cobalt Alloy Pipe Low Resistance Square / Round Tube Pipe
4j29 Kovar Iron Nickel Cobalt Alloy Pipe Low Resistance Square / Round Tube Pipe

Shanghai Tankii Alloy Material Co.,Ltd

Verified Supplier
11 Years
shanghai, shanghai
Since 1981
Business Type :
Manufacturer, Exporter
Total Annual :
8000000-100000000
Employee Number :
90~100
Certification Level :
Verified Supplier
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