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Description
4J29 is 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 lig bulbs, vacuum tubes, cathode ray tubes, and in vacuum systems in chemistry and other...
From factory Glass Sealing Alloy Strip Kovar/Dilver Po/4J29
(Common Name: Kovar, Nilo K, KV-1, Dilver Po, Vacon 12, ASTM F15, W.Nr 1.3912, UNS K94610 Ni29Co18)
| FeNiCo Glass Sealing Alloys | |
| Grade | 4J29,4J44 |
| Size | Strip:(0.03-0.1)mm*(180-250)mm (0.1-1.0)mm*(10-250)mm (1.0-3.0)mm*(100-250)mm Wire:0.1-6.0mm Bar:20-100mm(Hot forging) 2.0-20mm(Cold drawing) |
| Features | It has a certain linear expansion coefficient in the temperature range of -60ºC ~ + 400ºC, which can be matched with hard glass to seal firmly |
| Application | Suitable for 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%
| Grade | C | P | S | Mn | Si | Cu | Cr | Mo | Ni | Co | Fe |
| 4J29 | ≤0.03 | ≤0.02 | ≤0.02 | ≤0.5 | ≤0.3 | ≤0.2 | ≤0.2 | ≤0.2 | 28.5-29.5 | 16.8-17.8 | Bal. |
| 4J44 | ≤0.03 | ≤0.02 | ≤0.02 | ≤0.5 | ≤0.3 | ≤0.2 | ≤0.2 | ≤0.2 | 34.2-35.2 | 8.5-9.5 | Bal. |
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(Om*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 |
