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Ohmalloy Material Co.,Ltd

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Good quality Bimetallic Strip for sales
Good quality Bimetallic Strip for sales
I search for Nichrome plate long time, and successfully bought it from Ohmalloy material. OHMALLOY provide real good service in alloy service and can always help me in finding the correct resistance alloy.

—— Mike Harness

OHMALLOY can provie me only 1kg Kovar alloy wire 1.0mm with short time, that is really amazing. Thanks

—— Janey

Really professional in thermocouple wire and cable, what i want just can get from OHMALLOY

—— Chris

Enamelled Constantan 0.08mm, i never expect to get only 2kg of it. But OHMALLOY supply it to me with good quality. God Jesus! Such a reliable supplier from china

—— Aaron

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Customized 4J29 Kovar Alloy Sealing Machine / Electronic Devices Kovar Rod

China Customized 4J29 Kovar Alloy Sealing Machine / Electronic Devices Kovar Rod supplier
Customized 4J29 Kovar Alloy Sealing Machine / Electronic Devices Kovar Rod supplier Customized 4J29 Kovar Alloy Sealing Machine / Electronic Devices Kovar Rod supplier

Large Image :  Customized 4J29 Kovar Alloy Sealing Machine / Electronic Devices Kovar Rod

Product Details:

Place of Origin: China(Shanghai)
Brand Name: OHMALLOY
Certification: ISO
Model Number: 4J29

Payment & Shipping Terms:

Minimum Order Quantity: 20kg
Price: negotiable
Packaging Details: With Wooden Box
Supply Ability: 5000kg/month
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Detailed Product Description
Material: 4J29 Supply Type: Rod
Color: Primary Color Surface: Bright And Smooth

OhmAlloy-4J29 (Expansion alloy)
(Common Name: Kovar, Nilo K, KV-1, Dilver Po, Vacon 12)

OhmAlloy-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 is a nickel–cobalt ferrous alloy compositionally identical to Fernico, designed to be compatible with the thermal expansion characteristics of borosilicate glass (~5 × 10−6 /K between 30 and 200 °C, to ~10 × 10−6 /K at 800 °C) in order to allow direct mechanical connections over a range of temperatures. It finds application in electroplated conductors entering glass envelopes of electronic parts such as vacuum tubes (valves), X-ray and microwave tubes and some lightbulbs.

The name Kovar is often used as a general term for Fe–Ni alloys with these particular thermal expansion properties. Note the related particular Fe–Ni alloy Invar which exhibits minimum thermal expansion.

 

OhmAlloy-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.

 

OhmAlloy-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.

 

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.

 

 

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

 

Typical Physical properties

Density (g/cm3) 8.2
Electrical resistivity at 20℃(Ωmm2/m) 0.48
Temperature factor of resistivity(20℃~100℃)X10-5/℃ 3.7~3.9
Curie point Tc/ ℃ 430
Elastic Modulus, E/ Gpa 138

 

 

 

 

Coefficient of expansion

θ/℃ α1/10-6-1 θ/℃ α1/10-6-1
20~60 7.8 20~500 6.2
20~100 6.4 20~550 7.1

 

 

Customized 4J29 Kovar Alloy Sealing Machine / Electronic Devices Kovar Rod                                                                                                                           

Customized 4J29 Kovar Alloy Sealing Machine / Electronic Devices Kovar Rod

 

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Customized 4J29 Kovar Alloy Sealing Machine / Electronic Devices Kovar Rod

Contact Details
Ohmalloy Material Co.,Ltd

Contact Person: Mr. Qiu

Tel: +8613795230939

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