4J29 specification:plate,sheet,strip,rod,bar,wire,tube,etc.
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4J29 KOVAR
4J29 is also known as kovar alloy,ASTM F15,Nilo-K, UNS K94610 ,(FeNi29Co17),
YB/T5231-2005 ,(FeNi29Co18),Lockinvar,Alloy 12B,Sealing Alloy. Iron Nickel cobalt.
Note:
A Nickel-Iron-Cobalt, controlled expansion alloy containing 29% Nickel. It's coefficient of expansion (which decreases with rising temperature to the inflection point), matches the expansion rate of borosilicate glasses and aluminia ceramics. Applications include glass to metal seals in applications requiring high reliability or resistance to thermal shock, ie. high-power transmitting valves,transistor leads and heaters and photography flash bulbs.
1.Alloy grades and chemical composition consistent with the provisions of table 1
the chemical composition of Kovar(%) | ||||||||||
C | P | S | Mn | Si | Cu | Cr | Mo | Ni | Co | Fe |
Not more than≤ |
|
|
| |||||||
0.03 | 0.020 | 0.020 | 0.5 | 0.30 | 0.20 | 0.20 | 0.20 | 28.5-29.5 | 16.8-17.8 | balance |
2.The tensile strength of wire in line with the provisions of Table 2
Status code | State | Tensile strength,N/mm2 |
R 1/4I 1/2I 3/4I I | Soft state 1/4 Hard state 1/2 Hard state 3/4 Hard state Hard state | <585 585-725 655-795 725-860 >860 |
3.Strip tensile strength in line with the provisions of Table 3
Status code | State | Tensile strength,N/mm2 |
R 1/4I 1/2I 3/4I I | Soft state 1/4 Hard state 1/2 Hard state 3/4 Hard state Hard state | <570 520-630 590-700 600-770 >700 |
4.Alloy average linear expansion coefficient in line with the Table 4
Alloy Grades | Specimen heat treatment system | The average linear expansion coefficient a,10-6/ oC | ||
20-300 oC | 20-400 oC | 20-450 oC | ||
kovar | In hydrogen atmosphere heated to 900 ± 20 oC, insulation 1h, and then heated to 1100 ± 20 oC, insulation 15min, to not more than 5 oC / min rate of cooling to below 200 oC released. |
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4.6-5.2 |
5.1-5.5 |
5.Alloy typical expansion coefficient
Alloy Grades
| The average linear expansion coefficient a,10-6/ oC | |||||||
20- 200oC | 20- 300 oC | 20- 400oC | 20- 450oC | 20- 500oC | 20- 600oC | 20- 700oC | 20- 800oC | |
kovar | 5.9 | 5.3 | 5.1 | 5.3 | 6.2 | 7.8 | 9.2 | 10.2 |
