Ualloy-4j29 (Expansion alloy) (Common Name: Kovar, Nilo K, KV-1, Dilver Po, Vacon 12)

• Customization: Available
• Product Type: Bar,Wire
• Material: Nicr
• Model NO.: 4J29
• Condition: Annealed Polished
• Surface: Bright
• Packing: Wooden Case
• Density: 8.4G/M3
• Size: Customized
• Transport Package: Wooden Case
• Specification: customized
• Trademark: Ualloy
• Origin: China
• Production Capacity: 300t/Year
• Package Size: 100.00cm * 50.00cm * 50.00cm
• Package Gross Weight: 100.000kg

Product Description

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.

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(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