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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

 

 

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