Kovar Wire for Sealing Glass

• Product Type: Wire
• Material: Feni
• Carbon Content: Low Carbon
• Shape: Wire
• Condition: Soft
• Surface: Bright
• Model NO.: TANKII 429
• Diameter: 0.1-5mm
• MOQ: 30 Kgs
• Sample: Free
• Transport Package: Coil, Waterproof Paper, Wooden Case
• Trademark: TANKII-429
• Origin: China
• HS Code: 750522000
• Production Capacity: 50 Tons Per Month

Product Description

Kovar Wire for Sealing Glass

Grade : Kovar nickel-cobalt ferrous alloy/ 29HK/ 4J29
 
Classification : the alloy of expansion characteristics

Application: Kovar (trademark of CRS Holdings, inc., Delaware[1]) 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
 

Ni 28,5-29,5%	Fe 51,14-54,5%	C 0.03%	Si 0.3%	Mn 0,4 %	S o 0.015%
P 0.015%	o 17-18%	Ti 0.1%	Al 0.2%	Cu 0.2%	Cr 0,1 %

 
 
The thermal properties of alloy
 

Temperature coefficient of linear expansion αsr ? 10-6 K-1 in the temperature range, ° C								inflection point temperature, ° C No less		Heat treatment regime blanks and samples
20-80		20-100	20-300	20-400	20-450	20-500	20-800
-		-	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
Property								sintered		HIPed
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
(25-300 °C)								5.1
(25-400 °C)								4.9
(25-450 °C)								5.3
(25-500 °C)								6.2

 
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 expansion.