Premium Factory Price: Glass Sealing Alloy Kovar Metal 4J29 for Reliable Seals

4J29 is also known as Kovar alloy; it has a linear expansion coefficient similar to that of silicon boron hard glass at 20 to 450°C, so it is often called a glass seal alloy in production and processing. This alloy is a typical Fe-Ni-Co hard glass sealing alloy used internationally, with a high Curie point and good low-temperature microstructure stability. The alloy's oxide film is dense, can be well infiltrated by glass, and does not interact with mercury. It is suitable for use in mercury-containing discharge meters. It is the main sealing structure material for electric vacuum devices. It is mainly used for electric vacuum components and emission tubes. Glass sealing of oscillating tube, ignition tube, magnetron, transistor, sealing plug, relay, integrated circuit lead wire, chassis, housing bracket, etc. In the application, it should be ensured that the selected glass matches the expansion coefficient of the alloy, and its low-temperature structural stability can be strictly checked according to the temperature of use. Appropriate heat treatment should be carried out during processing to ensure that the material has good deep drawing elongation. The alloy is heated to 900°C±20°C in a hydrogen atmosphere for 1 hour, then heated to 1100°C±20°C, held for 15 minutes, and cooled to below 200°C at a rate of no more than 5°C/min.When forging materials are used, their air tightness should be strictly inspected. Chemical 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

Status number	State	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

Physical properties

Density	Resistivity at 20℃	Temperature coefficient of resistance (20℃~100℃)	Elastic modulus	Curie point
(g/cm³)	(Ωmm²/m)	X10^-5/℃	E/ Gpa	T_c/ ℃
8.2	0.48	3.7~3.9	138	430

Coefficient of expansion

θ/℃	α₁/10^-6℃^-1	θ/℃	α₁/10^-6℃^-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/℃	100	200	300	400	500
λ/ W/(m*℃)	20.6	21.5	22.7	23.7	25.4

Product heat treatment process
Stress relief annealing	Heat to 470~540℃, keep warm for 1~2 h. Cool in the furnace.
Annealing	Heating to 750~900℃ in vacuum
Holding time	14 min~1h.
Cooling method	Cool down to 200 ℃ at a rate not exceeding 10 ℃/min

Supply form and specification

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

Expansion alloy Series: 4J29 4J33 4J36 4J42Shijiazhuang Chengyuan Alloy Material Co., Ltd. is a high-tech enterprise specializing in the production of various alloy materials. It has an advanced and complete production line, including material smelting, surface cleaning, rolling, slitting, and a complete test process. Meet the corresponding quality inspection of different products. The company focuses on the production and supply of various electric heating alloys, expansion alloys, soft magnetic alloys, elastic alloys, high temperature alloys and all kinds of pure metals. The product forms include wire, flat wire, strip, plate, bar, foil, Seamless pipe, wire mesh, powder, etc. can meet the application needs of different customers. The various performance indicators of the product are strictly in accordance with the national standards. If customers put forward non-standard requirements, they can also be implemented by reference. Our products are widely used in heating equipment, machinery manufacturing, electric furnace production, instrumentation, household appliances, mineral mining, aerospace, petroleum and nuclear power and other industries, and have received good market feedback. Our products have stable delivery time, excellent quality, sophisticated packaging, and high repurchase rate. They are not only widely recognized in the domestic market, but also have a good reputation in the international market.

* OEM manufacturer * We will deliver the goods to the warehouse of the customer's agent in any city in China. * Terms of delivery: EXW, FCA, FOB, CIF, CPT, DAP * Mode of transport: Sea, Auto, Railway, Air and Express * Payment terms: Bank Transfer, Western Union, PayPal, Alipay * Quality Certificate: In order to improve the quality of products and services, with each order we provide a quality certificate for goods, which includes measured data - chemical composition, electrical resistivity, tensile strength, elongation, melting number, etc. Cheng Yuan Alloy Material Co., Ltd Email: [email protected] Tel .: +86 13673186216 +86 311 8803 3197