Prod Model: |
Ohmalloy4j29 |
Certificate: |
SGS, ISO, RoHS |
Sample: |
Free Sample |
Resistivity(μΩ.M): |
0.48 |
Density, G/cm3: |
8.2 |
Surface Treatment: |
Bright or Oxidation |
Width: |
9~250 mm |
Application: |
Sealing Material |
Elastic Modulus, E/ Gpa: |
138 |
Temperature Factor Of Resistivity: |
3.7~3.9 |
Curie Point Tc/ ºC: |
430 |
Product Type: |
Strip |
Material: |
Feni Alloy |
Carbon Content: |
No |
PCD: |
No |
ET: |
No |
Hole: |
No |
Product Description
OHMALLOY
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-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 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 |
Coefficient of expansion
θ/ºC | α1/10-6ºC-1 | θ/ºC | α1/10-6ºC-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/ºC | 100 | 200 | 300 | 400 | 500 |
λ/ W/(m*ºC) | 20.6 | 21.5 | 22.7 | 23.7 | 25.4 |
The heat treatment process |
Annealing for stress relief | Heated to 470~540ºC and hold 1~2 h. Cold down |
annealing | In vacuum heated to 750~900ºC |
Holding time | 14 min~1h. |
Cooling rate | No more than 10 ºC/min cooled to 200 ºC |
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 |
FAQ
1. What's the minimum quantity customer can order?
If we have your size in stock, we can provide any quantity you want.
If we do not have, for spool wire, we can produce 1 spool, about 2-3kg. For coil wire, 25kg.
2. How can you pay for small sample amount?
We have Western union account, wire transfer for sample amount also ok.
3. Customer do not have express account. How will us arrange the delivery for sample order?
Just need to provide your address information, we will check the express cost, you can arrange the express cost together with sample value.
4. What's our payment terms?
We can accept LC T/T payment terms, it also depending on delivery and total amount. Let's talk more in details after getting your detailed requirements.
5. Do you provide free samples?
If you want several meters and we have stock of your size, we can provide, customer need to bear the International express cost.
6. What's our working time?
We will give you reply through email/phone Online contact tool within 24 hours. No matter working day or holidays.
Ohmalloy Material Co., Ltd is a high-tech enterprise which specialized in making all kinds of alloy such as high resistance alloy, low-resistance copper nickel alloy, precision alloy, FeCrAl alloy and thermocouple Alloy.
Ohmalloy Material Co., Ltd have a full production line from melting, surface cleaning, rolling and slitting, full set of testing machine and can meet all kinds of technical requirement from customer. Our product is widely used in heating equipment, big steel mill, mineral, electrical equipment, food machinery, auto industry, aerospace industry. Our product not only is popular in domestic market, but also been exported to all over the world.
Our company aims to be the best-quality alloy producer in the world. We insist on developing the more advanced alloy strip technology, to serve all the customer, improve people's living level, make a more green earth in the future.
Our company supplies different kinds of products. With high quality and reasonable price. We stick to the principle of "quality first, service first, continuous improvement and innovation to meet the customers" for the management and "zero defect, zero complaints" as the quality objective. To perfect our service, we provide the products with good quality at the reasonable price.