Grade : Kovar nickel-cobalt ferrous alloy/ 29HK/ 4J29
Classification : the alloy of expansion characteristics
Application: Kovar (trademark of CRS Holdings, inc., Delaware) is a
nickel-cobalt ferrous alloy compositionally identical to Fernico 1,
designed to be compatible with the thermal expansion
characteristics of borosilicate glass (~5 × 10?6 /K between 30 and
200 °C, to ~10 × 10?6 /K at 800 °C) in order to allow direct
mechanical connections over a range of temperatures. It finds
application in electroplated conductors entering glass envelopes of
electronic parts such as vacuum tubes (valves), X-ray and microwave
tubes and some lightbulbs.
Chemical Composition in % Kovar
The thermal properties of alloy
|Temperature coefficient of linear expansion αsr ? 10-6 K-1 in the
temperature range, ° C||inflection point temperature, ° C|
|Heat treatment regime blanks and samples|
|-||-||4,6-5,6||4,6-5,2||-||5,9-6,4||-||420||samples and blanks annealing in hydrogen, a vacuum or protective
atmosphere at a temperature (960 ± 20) ° C, holding 1 hr., cooling
with the furnace or container to 200 ° C at a rate not exceeding 10
° C / min|
|Density / g cm3||8.0||8.35|
|Hardness / HV1||160||150|
|Youngs Modulus / GPa||138||138|
|reduction of area at fracture / %||30||30|
|yield strength / MPa||270||270|
|thermal conductivity / W/Km||17|
|Curie Temperature / °C||435|
|electrical resistivity Ω mm2 / m||0.49|
|specific heat J/gK||0.46|
|thermal expansion coefficient/10?6 K?1 (25 - 200 °C)||5.5|
The name Kovar is often used as a general term for Fe-Ni alloys
with these particular thermal expansion properties. Note the
related particular Fe-Ni alloy Invar which exhibits minimum thermal
TANKII, referring to the presence of high-power production, offers
customers buy alloy Kovar in the required quantities and ensures
minimum time shipments of rolled metal products, made on the basis
1) We can provide a free sample for testing but the freight at
2) Mill test certificate will be provided after production, If it
3) Good packing methods to keep goods no damage during delivery
4) We cooperate with many famous forwarder, will try our best to
choose the safty, convenience, quick, and cheap mode of
transportation for our customers.
(1) What is your min order?
For the Thermal spray wire, Our min order is 15kg .
(2) What is the wire weight of each spool?
The wire weight of each spool is around 15kg, also can be produce
according to customers' requirement.
(3)Whether can you provide a Mill Test Certification?
We can provide a Test certification after production.
(4)How can I contact with your company?
Our sales team is ready to serve you via Email, Telephone , Fax or
(5)Do you provide free samples?
Yes, we can provide a free sample for testing, The quantity based
on the material type.The freight is at customer's sides.
(6)What is your payment terms?
We accept 100% TT ( Telegraphic Transfer) in advance for small
orders( value under USD 2000).
For some big orders, we can accept 30% deposit, 70% balance before
shipment. For very small orders , we can accept paypal &
Western union payment.
More detail information, please feel free contact us!