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Bright Low Expansion Alloys Kovar 4J29 Wire 29HK Wire For Glass Sealing Alloy
Bright Low Expansion Alloys Kovar 4J29 Wire 29HK Wire For Glass Sealing Alloy
Bright Low Expansion Alloys Kovar 4J29 Wire 29HK Wire For Glass Sealing Alloy
Bright Low Expansion Alloys Kovar 4J29 Wire 29HK Wire For Glass Sealing Alloy
Bright Low Expansion Alloys Kovar 4J29 Wire 29HK Wire For Glass Sealing Alloy
Bright Low Expansion Alloys Kovar 4J29 Wire 29HK Wire For Glass Sealing Alloy
Bright Low Expansion Alloys Kovar 4J29 Wire 29HK Wire For Glass Sealing Alloy
Bright Low Expansion Alloys Kovar 4J29 Wire 29HK Wire For Glass Sealing Alloy
Specifications
Brand Name :
OHMALLOY
Model Number :
4J29
Certification :
SGS,ISO
Place of Origin :
China(Shanghai）
MOQ :
30KG
Price :
20-50USD/KG
Payment Terms :
L/C, T/T, , MoneyGram
Supply Ability :
25000 KG per month
Delivery Time :
25-35 working days
Packaging Details :
Plastic shaft, Roll bag, Drum
Material :
Fe Ni Alloy
Density :
8.2 G/cm3
Wire Diameter Range :
0.05mm-8mm
Package :
Plastic shaft, Roll bag, Drum
Common Name :
Kovar, Nilo K, KV-1, Dilver Po, Vacon 12
Surface :
Bright
Application :
Sealing Material For Glass
Temperature Factor Of Resistivity(20℃~100℃)X10-5/℃ :
3.7~3.9
Description

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.
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.

Application: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


Bright Low Expansion Alloys Kovar 4J29 Wire 29HK Wire For Glass Sealing Alloy

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
20~200 5.9 20~600 7.8
20~300 5.3 20~700 9.2
20~400 5.1 20~800 10.2
20~450 5.3 20~900 11.4



Thermal conductivity

θ/℃ 100 200 300 400 500
λ/ W/(m*℃) 20.6 21.5 22.7 23.7 25.4

The heat treatment process
Annealing for stress relief Heated to 470~540℃ and hold 1~2 h. Cold down
annealing In vacuum heated to 750~900℃
Holding time 14 min~1h.
Cooling rate No more than 10 ℃/min cooled to 200 ℃


Style of supply

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

Product tags

aluminum wire sizing

,

phosphorized steel wire

,

24 awg silicone wire
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Bright Low Expansion Alloys Kovar 4J29 Wire 29HK Wire For Glass Sealing Alloy

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Product Detail
Brand Name :
OHMALLOY
Model Number :
4J29
Certification :
SGS,ISO
Place of Origin :
China(Shanghai）
MOQ :
30KG
Price :
20-50USD/KG
Contact Supplier
Bright Low Expansion Alloys Kovar 4J29 Wire 29HK Wire For Glass Sealing Alloy
Bright Low Expansion Alloys Kovar 4J29 Wire 29HK Wire For Glass Sealing Alloy
Bright Low Expansion Alloys Kovar 4J29 Wire 29HK Wire For Glass Sealing Alloy
Bright Low Expansion Alloys Kovar 4J29 Wire 29HK Wire For Glass Sealing Alloy

Ohmalloy Material Co.,Ltd

Verified Supplier
10 Years
shanghai, shanghai
Since 2008
Business Type :
Manufacturer, Distributor/Wholesaler, Exporter, Trading Company
Main Products :
FeCrAl Alloy, Nickel Strip, Bimetallic Strip
Total Annual :
4000000-6000000
Employee Number :
20~50
Certification Level :
Verified Supplier
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