Ohmalloy Material Co.,Ltd
| Supply Ability | 5000kg/month |
| Packaging Details | In Coil |
| Material | 4J29 |
| Supply Type | Wire |
| Color | Primary Color |
| Surface | Bright and Smooth |
| Brand Name | OHMALLOY |
| Model Number | 4J29 |
| Certification | ISO |
| Place of Origin | China(Shanghai) |
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Product Specification
| Supply Ability | 5000kg/month | Packaging Details | In Coil |
| Material | 4J29 | Supply Type | Wire |
| Color | Primary Color | Surface | Bright and Smooth |
| Brand Name | OHMALLOY | Model Number | 4J29 |
| Certification | ISO | Place of Origin | China(Shanghai) |
| High Light | invar alloy ，kovar alloy | ||
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.
| 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 |
| 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 |
| 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 |
Company Details
Business Type:
Manufacturer,Distributor/Wholesaler,Exporter,Trading Company
Year Established:
2008
Total Annual:
4000000-6000000
Employee Number:
20~50
Ecer Certification：
Verified Supplier
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... 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...
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