Shanghai Tankii Alloy Material Co.,Ltd
| Payment Terms | T/T, Western Union, L/C, Paypal |
| Supply Ability | 30000KG per month |
| Delivery Time | 4-8 weeks |
| Packaging Details | Waterproof paper, Carton and Wooden Case |
| Shape | Strip, Foil, Sheet, Wire |
| Condition | Bright/ Oxidized; Soft/ Hard |
| Standard | YB/T5231-2005 / ГОСТ 14080-78 |
| Color | Silver |
| Weight of coil | 1~45 KG |
| Brand Name | Alloy 4J29 |
| Model Number | Kovar / 4J29 |
| Certification | ISO 9001 and RoHS |
| Place of Origin | China |
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Product Specification
| Payment Terms | T/T, Western Union, L/C, Paypal | Supply Ability | 30000KG per month |
| Delivery Time | 4-8 weeks | Packaging Details | Waterproof paper, Carton and Wooden Case |
| Shape | Strip, Foil, Sheet, Wire | Condition | Bright/ Oxidized; Soft/ Hard |
| Standard | YB/T5231-2005 / ГОСТ 14080-78 | Color | Silver |
| Weight of coil | 1~45 KG | Brand Name | Alloy 4J29 |
| Model Number | Kovar / 4J29 | Certification | ISO 9001 and RoHS |
| Place of Origin | China | ||
| High Light | 4J29 Precision Strip ，Stamping IC Framework Precision Strip ，Shell Metal Ceramic Nickel Alloy Strip | ||
4j29 Strip 0.15mm*20mm for Stamping Shell Metal Ceramic
(Common Name: Kovar, Nilo K, KV-1, Dilver Po, Vacon 12)
Alloy-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)
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.
Alloy-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.
Alloy-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(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 |
Company Details
Business Type:
Manufacturer,Exporter
Year Established:
1981
Total Annual:
8000000-100000000
Employee Number:
90~100
Ecer Certification：
Verified Supplier
Shanghai Tankii Alloy Material Co., Ltd.specialized in production of Resistance Heating Alloy, Nickel Chromium Alloy, Iron Chromium Aluminum Alloy, Nickel Aluminum Alloy, Manganin, Copper Nickel Alloy, thermocouple wire, pure nickel and other precision alloy materials in the form of round wire, ribb... Shanghai Tankii Alloy Material Co., Ltd.specialized in production of Resistance Heating Alloy, Nickel Chromium Alloy, Iron Chromium Aluminum Alloy, Nickel Aluminum Alloy, Manganin, Copper Nickel Alloy, thermocouple wire, pure nickel and other precision alloy materials in the form of round wire, ribb...
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