What material is Kovar?
iron-nickel-cobalt alloy
Kovar is an iron-nickel-cobalt alloy with a coefficient of thermal expansion similar to that of hard (borosilicate) glass. This makes it especially suitable for uses which require a matched-expansion seal between metal and glass parts.
What is Kovar used for?
Light bulbs are perhaps the most common example of the use of Kovar, but this alloy is used in many different products. Kovar is also used to manufacture x-ray tubes, microwave tubes, diodes, transistors, and more. Kovar may not be a household name, but this incredible alloy is still used in products in every home.
What is the CTE of Kovar?
materials
| Material Property | Kovar |
|---|---|
| Modulus of Elasticity (GPa) | 138 |
| Poisson’s Ratio | 0.317 |
| Coefficient of Thermal Expansion (1 x 10^-6/°C) | 4.9 – 6.2 |
| Thermal Conductivity (W/m K) | 17 |
Is Kovar stainless steel?
Kovar® – UNS K94610. Kovar® is an iron cobalt nickel alloy with a coefficient of thermal expansion like that of hard glass.
Who makes Kovar?
CRS Holdings, inc.
Kovar (trademark of CRS Holdings, inc., Delaware) is a nickel–cobalt ferrous alloy compositionally identical to Fernico 1, designed to have substantially the same thermal expansion characteristics as borosilicate glass (~5 × 10−6 /K between 30 and 200 °C, to ~10 × 10−6 /K at 800 °C) to allow a tight mechanical joint …
What is Kovar and Invar?
Kovar is a nickel-iron-cobalt alloy known for its excellent thermal expansion characteristics. Invar is a nickel-iron alloy that exhibits superior dimensional stability across. extreme temperatures.
Is Kovar ductile?
Forming. Good ductility makes KOVAR readily formable.
Is Kovar corrosion resistant?
Kovar end uses are usually glass sealing in the electronics industry. Though Nickel has good resistance and it is present at 29% – which is pretty high – you have to account for the 53% iron where the iron oxide has to be controlled for to prevent rusting.
Is Kovar magnetic?
Kovar is magnetic at all temperatures below the Curie point. Magnetic properties will depend upon heat treatment; the lower the hardness, the higher the permeability values and lower hysteresis loss.
Does Kovar oxidize?
The oxide formed on Kovar oxidised in air at 700 and 800 °C has been analysed and shown to be comprised of a layered structure with several different oxides, some of which have been previously overlooked in the literature.