Low Expansion Alloy Kovar 4j29 Wire for Glass Sealing Alloy

• Application: Aviation, Electronics, Industrial, Medical, Chemical
• Standard: JIS, GB, DIN, BS, ASTM, AISI
• Purity: 29%Ni
• Alloy: Alloy
• Type: Fe Ni Wire
• Powder: Not Powder
• Model NO.: 4j29
• Material: Fe- Ni Alloy
• Surface: Smooth and Bright
• Condition: Soft
• Density: 8.1
• Resisivity: 0.78
• Curie Point: 230
• Chemical Composition: Feni36
• Grade: 4j36/ Uns K93600/ AISI/ASTM Invar36/W. Nr 1.3912
• Thermal Conductivity: 11
• Elastic Modulus: 144
• Transport Package: Wooden Case
• Specification: 1.5x200
• Trademark: HUONA
• Origin: Shanghai, China
• HS Code: 7505120000
• Production Capacity: 2000tons/Year

Product Description

Low Expansion Alloy Kovar 4j29 Wire for Glass Sealing Alloy

(Common Name: Kovar, NiFeCo29, NiCoFe294,Nilo K)

Controlled Expansion and Glass Sealing Alloys
German standard number	Tradename	DIN	UNS
1.3912	Alloy 36	17745	K93600/93601
1.3917	Alloy 42	17745	K94100
1.3922	Alloy 48	17745	K94800
1.3981	Pernifer2918	17745	K94610
2.4478	NiFe 47	17745	N14052
2.4486	NiFe47Cr	17745	-

General Description
Kovar is a nominal 29%Ni-17%Co-54%Fe alloy that is a well-known glass-sealing alloy suitable for sealing to hard glasses. Kovar has a nominal expansion coefficient of approximately 5 ppm/°C and inflection temperature of ~450 °C (840 °F).

4J29 also known as Fe-Ni-Co Glass Sealing 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. 

Kovar (ASTM F15) has been used for making hermetic seals with the harder Pyrex glasses and ceramic materials. This alloy has found wide application in power tubes, microwave tubes, transistors, and diodes. In integrated circuits, it has been used for the flat pack and the dual-in-line package.

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.

Chemical Domposition  

alloy	C	Mn	Si	P	S	Ni	Cr	Co	Cu	Mo	Fe
4J29	≤0.03	≤0.50	≤0.30	≤0.020	≤0.020	28.5~29.5	≤0.20	16.8~17.8	≤0.2	≤0.2	balance

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(OMmm^2/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

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

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

Style of supply

Alloys Name	Type	Dimension
4J29	Wire	D= 0.1~8mm
4J29	Strip	W= 5~250mm	T= 0.1mm
4J29	Foil	W= 10~100mm	T= 0.01~0.1mm
4J29	Bar	Dia= 8~100mm	L= 50~1000mm

FAQ 
1. How long i can get the feedback after we sent the enquiry?
A: We will reply you within 12 hours in working day.

2. How can I get some samples?
A: We are pleased to offer you sample, the delivery time is about 4-7 days.

3. Are you a factory?
A: Yes. We are. We have specialized in this field over 10 Year.

4. What is the delivery time?
A:15 days normally, detail delivery date should be decided according to production season and order quantity.