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4j29 Kovar Alloy Wire Fe-Ni-Co Glass Sealing

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JINXING MATECH CO LTD

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4j29 Kovar Alloy Wire Fe-Ni-Co Glass Sealing

Brand Name : JX

Model Number : 4j29

Certification : ISO

Place of Origin : china

MOQ : 100kgs

Price : Negotiable

Payment Terms : L/C, T/T

Supply Ability : 3000T

Delivery Time : 35days

Packaging Details : Standard wooden case

Product Type : 4j29 Fe-Ni-Co Glass Sealing Alloy Wire Kovar Alloy Wire

Material : Feni Alloy

Carbon Content : low

Transport Package : wooden case

Shape : round bar

Condition : soft

Surface : Bright

Origin : China

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4j29 Fe-Ni-Co Glass Sealing Alloy Wire Kovar Alloy Wire

Kovar Alloy Wire is a iron-nickel-cobalt, low expansion alloy whose chemical composition is controlled within narrow limits to assure precise uniform thermal expansion properties. Kovar alloy has been used for making hermetic seals with the harder Pyrex glasses and ceramic materials.

4J29 (Expansion alloy)
(Common Name: Kovar, Nilo K, KV-1, Dilver Po, Vacon 12)4J29 also known as Kovar alloy. it was 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.

Kovar Alloy Wire Mainly used in electric vacuum components and emission control, shock tube, igniting tube, glass magnetron, transistors, seal plug, relay, integrated circuits lead, chassis, brackets and other housing sealing.

Kovar Alloy Wire Normal composition%

Ni	28.5~29.5	Fe	Bal.	Co	16.8~17.8	Si	≤0.3
Mo	≤0.2	Cu	≤0.2	Cr	≤0.2	Mn	≤0.5
C	≤0.03	P	≤0.02	S	≤0.02

Tensile Strength, MPa

Code of condition	Condition	Wire	Strip
R	Soft	≤585	≤570
1/4I	1/4 Hard	585~725	520~630
1/2I	1/2 Hard	655~795	590~700
3/4I	3/4 Hard	725~860	600~770
I	Hard	≥850	≥700

Kovar Alloy Wire Typical Physical properties

Density (g/cm3)	8.2
Electrical resistivity at 20ºC(Om*mm2/m)	0.48
Temperature factor of resistivity(20ºC~100ºC)X10-5/ºC	3.7~3.9
Curie point Tc/ ºC	430
Elastic Modulus, E/ Gpa	138

Kovar Alloy Wire picture:
4j29 Kovar Alloy Wire Fe-Ni-Co Glass Sealing

4j29 Kovar Alloy Wire Fe-Ni-Co Glass Sealing

4J29 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 oxide and cobalt 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.

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