China Ualloy-4j29 (Expansion alloy) (Common Name: Kovar, Nilo K, KV-1, Dilver Po, Vacon 12), Find details about China Kovar Bar, Nilo K from Ualloy-4j29 (Expansion alloy) (Common Name: Kovar, Nilo K, KV-1, Dilver Po, Vacon 12)
Ualloy-4J29 (Expansion alloy)
(Common Name: Kovar, Nilo K, KV-1, Dilver Po, Vacon 12)
Ualloy-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.
Ualloy-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.
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.
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 20ºC(OHM*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 | ||
Ualloy-4J29 | Wire | D= 0.1~8mm | ||
Ualloy-4J29 | Strip | W= 5~250mm | T= 0.1mm | |
Ualloy-4J29 | Foil | W= 10~100mm | T= 0.01~0.1 | |
Ualloy-4J29 | Bar | Dia= 8~100mm | L= 50~1000 | |