29HK / Kovar Plate/Rod Fe Ni alloy bar
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).
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.
Chemical Composition
Grade |
C% |
P% |
S% |
Mn% |
Si% |
|
Cu% |
Cr% |
Mo% |
Ni% |
Co% |
Fe% |
Kovar |
Max 0.03 |
Max 0.020 |
Max 0.020 |
Max 0.50 |
Max 0.30 |
|
Max 0.20 |
Max 0.20 |
Max 0.20 |
28.5-29.5 |
16.8-17.8 |
Bal. |
Specifications
Grade |
UNS |
Werkstoff Nr. |
ASTM |
Kovar |
K94610 |
1.3981 |
F15 |
|
Physical Properties
Grade |
Density |
Melting Point |
Kovar |
8.17 g/cm3 |
1449°C |
Mechanical Properties
Grade |
Tensile Strength N/mm² |
Soft |
1/4 Hard |
1/2 Hard |
3/4 Hard |
Full Hard |
Kovar Strip |
<570 |
520-630 |
590-700 |
600-770 |
>700 |
Kovar Wire |
<585 |
585-725 |
655-795 |
725-860 |
>860 |
Coefficient of Expansion
Alloy |
Linear Coefficient of Thermal Expansion ā,10-6/ºC |
20-200ºC |
20-300ºC |
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 |
Size Range:
*Sheet---Thickness 0.1mm~40.0mm, width:≤300mm,Condition: cold rolled(hot), bright, bright annealed
*Round Wire---Dia 0.1mm~Dia 5.0mm,Condition: cold drawn, bright, bright annealed
*Flat Wire---Dia 0.5mm~Dia 5.0mm,length:≤1000mm,Condition:flat rolled, bright annealed
*Bar---Dia 5.0mm~Dia 8.0mm,length:≤2000mm,Condition:cold drawn,bright, bright annealed
Dia 8.0mm~Dia 32.0mm,length:≤2500mm,Condition:hot rolled,bright, bright annealed
Dia 32.0mm~Dia 180.0mm,length:≤1300mm,Condition:hot forging,peeled, turned, hot treated
*Capillary---OD 8.0mm~1.0mm,ID 0.1mm~8.0mm,length:≤2500mm,Condition: cold drawn, bright, bright annealed
*Pipe---OD 120mm~8.0mm,ID 8.0mm~129mm,length:≤4000mm,Condition: cold drawn, bright, bright annealed