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Kovar1 Controlled Expansion Alloy
Kovar1 (aka ASTM F-15, Pernifer 29182, Dilvar P13 and NILO K4) is a controlled expansion alloy. It is a Nickel Iron alloy with 29% Nickel, 17% Cobalt and the remaining balance is Iron. The expansion characteristics of Kovar match both borosilicate (or Pyrex) glasses and alumina ceramics, making it one of the most popular of the controlled expansion alloys for hermetic sealing applications. Kovar is produced to ensure good properties for machining and deep drawing, and is a porosity free product.
Kovar Products
Ed Fagan Europe Ltd. stocks Kovar in a variety of forms and dimensions. Below are most of the standard stock form/sizes. If you do not see the size or form of Kovar that you require, please call one of our materials experts; our sales people are very knowledgeable and can assist you. We can cut, slit, shear, or center less grind Kovar to your exact specifications, and we also have tremendous versatility when it comes to custom sizes, packages, and unusual materials.
| Kovar Sheet | |
Kovar Sheet Thickness |
Kovar Sheet Thickness |
0.254 mm Kovar Sheet |
1.574 mm Kovar Sheet |
0.381 mm Kovar Sheet |
1.778 mm Kovar Sheet |
0.509 mm Kovar Sheet |
2.032 mm Kovar Sheet |
0.635 mm Kovar Sheet |
2.108 mm Kovar Sheet |
0.762 mm Kovar Sheet |
2.286 mm Kovar Sheet |
0.889 mm Kovar Sheet |
2.540 mm Kovar Sheet |
1.016 mm Kovar Sheet |
2.667 mm Kovar Sheet |
1.270 mm Kovar Sheet |
3.175 mm Kovar Sheet |
1.524 mm Kovar Sheet |
|
| Kovar Plate | |
Kovar Plate Thickness |
Kovar Plate Thickness |
4.165 mm Kovar Plate |
9.525 mm Kovar Plate |
4.749 mm Kovar Plate |
11.099 mm Kovar Plate |
5.842 mm Kovar Plate |
12.70 mm Kovar Plate |
6.350 mm Kovar Plate |
15.875 mm Kovar Plate |
7.137 mm Kovar Plate |
19.050 mm Kovar Plate |
7.924 mm Kovar Plate |
25.40 mm Kovar Plate |
| Kovar Rod | |
Kovar Rod Diameter |
Kovar Rod Diameter |
1.270 mm Kovar Rod |
22.225 mm Kovar Rod |
1.524 mm Kovar Rod |
25.40 mm Kovar Rod |
1.587 mm Kovar Rod |
28.575 mm Kovar Rod |
2.285 mm Kovar Rod |
31.750 mm Kovar Rod |
2.362 mm Kovar Rod |
34.925 mm Kovar Rod |
2.438 mm Kovar Rod |
38.10 mm Kovar Rod |
2.540 mm Kovar Rod |
41.275 mm Kovar Rod |
3.175 mm Kovar Rod |
44.450 mm Kovar Rod |
3.962 mm Kovar Rod |
47.625 mm Kovar Rod |
4.762 mm Kovar Rod |
50.80 mm Kovar Rod |
6.350 mm Kovar Rod |
57.150 mm Kovar Rod |
7.924 mm Kovar Rod |
63.50 mm Kovar Rod |
9.525 mm Kovar Rod |
77.470 mm Kovar Rod |
12.70 mm Kovar Rod |
88.90 mm Kovar Rod |
15.875 mm Kovar Rod |
152.40 mm Kovar Rod |
19.050 mm Kovar Rod |
|
| Kovar Strip/Coil Annealed | |
Kovar Strip/Coil Thickness |
Kovar Strip/Coil Thickness |
0.127 mm Kovar Strip/Coil |
0.762 mm Kovar Strip/Coil |
0.254 mm Kovar Strip/Coil |
1.016 mm Kovar Strip/Coil |
0.381 mm Kovar Strip/Coil |
1.270 mm Kovar Strip/Coil |
0.508 mm Kovar Strip/Coil |
1.524 mm Kovar Strip/Coil |
0.635 mm Kovar Strip/Coil |
|
| Kovar Strip/Coil Tempered | |
Kovar Strip/Coil Thickness |
Kovar Strip/Coil Thickness |
0.254 mm Kovar Strip/Coil |
0.381 mm Kovar Strip/Coil |
Kovar Applications
Power tubes, microwave tubes, transistors, diodes, hybrid packages, and other kinds of scientific instruments.
Kovar Properties
| Kovar Alloy Physical Properties | ||
Density |
lb/cu in |
0.302 |
Specific Gravity |
|
8.36 |
Curie Temp |
°F |
815 |
|
°C |
435 |
Melting Point |
°F |
2640 |
|
°C |
1449 |
Electrical Resistivity |
Micro-ohm-cm |
40 |
|
ohm-cir mil/ft |
294 |
Thermal Conductivity |
W/cm °C |
0.17 |
|
BTU-in/sq. ft-hr- |
120 |
Specific Heat |
Cal/g- °C |
0.11 |
|
BTU/lbm- °F |
0.11 |
Thermal Expansion |
ppm / °F (75°F to 842°F) |
2.9 |
|
ppm / °C (25°C to 450°F) |
5.3 |
| Kovar Mechanical Properties | ||
Tensile Strength |
ksi |
75 |
|
MPa |
518 |
Yield Strength |
ksi |
40 |
|
MPa |
276 |
Elongation |
% in 2 in. |
30 |
Typical Hardness Ann. |
Rockwell HRB |
80 |
Modulus of Elasticity |
Mpsi |
30 |
|
kMPa |
207 |
| Kovar Chemistry | |
maximum % unless noted |
|
Iron |
Bal |
Nominal Nickel |
29 |
Nominal Cobalt |
17 |
Carbon |
0.02 |
Silicon |
0.20 |
Chromium |
0.20 |
| Kovar Specifications | ||
ASTM F-15/F-1466 |
MIL 1-23011 CL 1 |
AMS 1-23011 CL 1 |
| Kovar Alloy Linear Coefficient of Thermal Expansion | |||
Degree C |
Degree C |
||
30-100 |
-- |
30-450 |
5.1 - 5.5 |
30-150 |
-- |
30-475 |
-- |
30-200 |
5.5 |
30-500 |
6.2 |
30-250 |
-- |
30-525 |
-- |
30-300 |
5.1 |
30-550 |
-- |
30-325 |
-- |
30-600 |
7.9 |
30-350 |
-- |
30-700 |
9.3 |
30-375 |
-- |
30-800 |
10.4 |
30-400 |
4.6 - 5.2 |
30-900 |
11.5 |
30-425 |
-- |
30-1000 |
-- |
Underscored face values are the limits specified in MIL-I-23011C
|
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ED FAGAN Europe Ltd. supplies the highest quality special purpose alloys and metals for Aerospace/Aviation, Defence, Magnetic, Electronics, Telecommunications, Lighting, Optical, Ceramics, Heat Treating, Medical, and other high-technology industries.
1. Trademark Carpenter Technology Corp., Reading PA
2. Trademark ThyseenKrupp-VDM, Germany
3. Trademark Imphy Alloys, France
4. Trademark Special Metals Corporation, USA
Controlled Expansion Alloys
Ed Fagan Europe Ltd. stocks a variety of similar alloys for low expansion, controlled expansion, glass-to-metal or ceramic sealing applications that may also satisfy your needs. EFI carries:Invar
Kovar
42 Alloy
42-6 Alloy
46 Alloy
48 Alloy
52 Alloy
And we also have a large selection of other types of specialty metals and alloys for high technology applications, including:
Electrical/Electronic Nickel
Soft Magnetic Alloys
Refractory Metals and Alloys
Hard to Find Materials