Kovar® (UNS K94610) ASTM F15 Alloy
Ed Fagan Inc. is a leading global supplier of the nickel-iron-cobalt alloy, Kovar® Alloy (ASTM F15). This unique controlled expansion alloy is a combination of 29% nickel, 17% cobalt and the balance iron. Developed in the 1930’s, under the guidance of Westinghouse it was the first stress-free, glass-to-metal seal capable of maintaining its integrity in a range of environments. Today it is still the preferred alloy for hermetic sealing.
Product expansion characteristics match both borosilicate (Pyrex®) glasses and alumina ceramics making it one of the most popular of the controlled expansion alloys for hermetic sealing applications. A porosity free product, it is produced to ensure good properties for machining and deep drawing.
In manufacturing ASTM F15 Alloy, controls are exercised at various stages to assure close limits of thermal expansion and other desired properties. Procedural tests to measure uniformity and high-quality are thermal expansion, transformation, cupping, for “drawability”, Rockwell hardness, grain size, free from gas and glass sealing. Rod and wire soundness are assured by subjecting the primary bar stock to ultrasonic testing and microscopic examination of the ends. Thorough inspection of sheets guards against surface defects.
Kovar® or ASTM F15 Alloy is manufactured not to undergo phase transformation from gamma to alpha at temperatures above minus 80 °C (minus 176 °F). Actual transformation is considerably lower. Where extremely low temperatures are service requirements, special selected alloy melts with specific transformation points can be supplied. Kovar® ( ASTM F15) is a stock material from Ed Fagan Inc. and has been tested by our mills to not transform to -196°C.
For over fifty years, Ed Fagan Inc. has been a leading supplier of Kovar® and controlled expansion alloys. With warehouses in NJ and CA, our stock of coil, strip, plate, round bar/rod, sheet and wire rod is available in numerous sizes, tempers and conditions to meet the global demands of customers. All standard stock items are ready-to-ship for those in immediate need of materials.
Various manufacturers have produced ASTM F15 under their own brand names. Perhaps, these names are familiar to you, Kovar®, Pernifer® 2918, Dilver® P1 and NILO® K.
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Dilver is a registered trademark of Aperam Alloys Imphy, France
Kovar is a registered trademark of CRS Holdings LTD., Delaware, USA
NILO is a registered trademark of Huntington Alloys Corp., West Virginia, USA.
Pernifer is a registered trademark of VDM Metals GmbH, Germany