Glass sealed and controlled expansion Kovar alloys
* kovar alloy, ASTM F15, Nilo-K, UNS K94610 (FeNi29Co17), Chinese 4J29
*Specifications:ASTM F15; DIN 17745; S.E.W. 385; Werkstoff Nr. 1.3981; AFNOR NF A54-301

Kovar Alloy, also know as ASTM F-15, NILO K, Pernifer 2918, Rodar, and Dilvar P1 is Nickel-Iron-Cobalt, controlled expansion alloy containing 29% Nickel.

It’s coefficient of expansion (which decreases with rising temperature to the inflection point), matches the expansion rate of borosilicate glasses and aluminia ceramics.

Applications include glass to metal seals in applications requiring high reliability or resistance to thermal shock, ie.high~power transmitting valves, transistor leads and heaters and photography flash bulbs.

Permalloy Invar 4J29 1J50 1J49 Foil Strip Tapes Specification:

Alloy Type	Trade Name	UNS No.	Specifications	Forms Of Supply
				Rod	Strip	Wire	Sheet
Ni29Co17	Kovar	K94610	ASTM F15	√	√	√	√
FeNi36	Invar 36	K93603	ASTM 1684	√	√		√
FeNi32Co5	Super Invar 32-5	KI93500	ASTMF1684	√	√		√
FeNi27Co25	Ceramvar	F1466	ASTMF1466	√	√	√	√
FeNi42	Alloy 42	K94100	ASTM F30	√	√		√
FeNi46	Alloy 46	K94600	ASTM F30	√	√		√
FeNi48	Alloy 48	K94800	ASTMF30	√	√		√
FeNi50	Alloy 52	K95050	ASTM F30	√	√	√	√

Permalloy Invar 4J29 1J50 1J49 Foil Strip Tapes Picture:

 

Item	1J33	3J01	3J9	4J29	4J32	4J33	4J45	FeNi50	Invar36
C	≤0.05	≤0.05	0.22-0.26	≤0.03	≤0.05	≤0.03	≤0.05	≤0.05	≤0.1
Mn	≤0.05	≤1.00	1.80-2.20	≤0.5	0.2-0.6	≤0.5	≤0.8	≤0.8	≤0.5
Fe	Rest
P	≤0.020	≤0.020	≤0.03	≤0.02	≤0.02	≤0.02	≤0.02	≤0.02	≤0.006
S	≤0.020	≤0.020	≤0.020	≤0.02	≤0.02	≤0.02	≤0.02	≤0.02	≤0.04
Si	0.30-0.6	≤0.80	1.30-1.70	≤0.3	≤0.2	≤0.3	≤0.3	≤0.3	≤0.35
Ni	32.8-33.8	34.5-36.5	9.0-10.5	28.5-29.5	31.5-33	28.5-29.5	44.5-45.5	49.5-50.5	35-38
Al	1.0-2.0	1.00-1.80	--	--	--	--	≤0.1	≤0.1	--
Co	--	--	--	16.8-17.8	3.2-4.2	16.8-17.8	-	-	-
Ti	-	2.70-3.20	-	-	-	-	-	-	-
Cu	-	--	--	--	≤0.2	0.4-0.8	≤0.2	--	--
Cr	--	11.5-13.0	19.0-20.5	≤0.2	--	≤0.2	--	--	--
Mo	--	--	1.60-1.85	≤0.2	--	≤0.2	--	--	--