China Kovar Strip Kovar Sheet

(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-4J29 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.
Mainly used inelectric vacuumcomponents andemission control,shocktube, igniting tube, glassmagnetron, transistors, sealplug, relay, integrated circuitslead, chassis, brackets and otherhousingsealing.
Normal composition%

Ni28.5~29.5FeBal.Co16.8~17.8Si≤0.3Mo≤0.2Cu≤0.2Cr≤0.2Mn≤0.5C≤0.03P≤0.02S≤0.02

Tensile Strength, MPa Typical Physical properties

Density (g/cm3)8.2Electrical resistivity at 20ºC(mm2/m)0.48Temperature factor of resistivity(20ºC~100ºC)X10-5/ºC3.7~3.9Curie pointTc/ ºC430Elastic Modulus, E/ Gpa138

Coefficient of expansion

θ/ºCα1/10-6ºC-1θ/ºCα1/10-6ºC-120~607.820~5006.220~1006.420~5507.120~2005.920~6007.820~3005.320~7009.220~4005.120~80010.220~4505.320~90011.4

Thermal conductivity

θ/ºC100200300400500λ/ W/(m*ºC)20.621.522.723.725.4

The heat treatment process

Annealing for stress reliefHeated to 470~540ºC and hold 1~2 h. Cold downannealingIn vacuum heated to 750~900ºCHolding time 14 min~1h.Cooling rateNo more than 10 ºC/min cooled to 200 ºC

Style of supply

Alloys NameTypeDimensionUAlloy-4J29WireD=0.1~8mmUAlloy-4J29StripW= 5~250mmT= 0.1mmUAlloy-4J29FoilW= 10~100mmT= 0.01~0.1UAlloy-4J29BarDia=8~100mmL=50~1000