Kovar Alloy® standard specification for Iron-Nickel-Cobalt Sealing Alloy
Sheet Thickness:0.1mm~3.5mm
Plate Thickness:3.5mm~4.0mm
Bar Dia 32.0mm~Dia180.0mm
Pipe OD 120mm~8.0mm,ID 8.0~129
Wire Dia 0.1mm-Dia5.0mm
Products Application
It is applied to hard glass to metal seals
Description
Kovar Alloy is a vacuum melted, iron-nickel-cobalt, low expansion alloy whose chemical composition is controlled within narrow limits to assure precise uniform thermal expansion properties. Extensive quality controls are employed in the manufacture of this alloy to ensure uniform physical and mechanical properties for ease in deep drawing, coining, stamping and machining.
Parameter
TABLE 1 Chemical Requirement
Element Composition,%
C ≤ 0.03
P≤ 0.020
S≤ 0.020
MN≤ 0.50
SI≤ 0.30
CU≤ 0.20
CR≤ 0.20
MO≤ 0.20
NI 28.5-29.5
CO 16.8-17.8
FE remainder
Notes:
1.Under the condition that the average coefficient of the linar expansion meets the requirements of the standard,the content of nickel and cobalt are allowed to deviate from the stated range.
2.the shape and dimensions of the alloys are in compliance with GB/T14985
TABLE 2 Physical Requirement
Property Target
Specific gravity 8.36
Density lb/cu in 0.302 / kg/cu m 8359
Thermal conductivity Btu-in/ft²/hr/°F120 / W/m-K173
Curie temperature °F815 / 435°C
Melting Point °F 2640 / °C1450
Modulus of elasticity psi x 10(6) 20 / psi x 10(6) 138
Electrical resistivity ohm-cir mil/ft 294 / microhm-mm 490
TABLE 3 Tensile Strength of wire
Symbol Status Tensile Strength/MPa
R annealed <585
1/4 I 1/4hard 585-725
1/2I 1/2hard 655-795
3/4I 3/4hard 725-860
I unannealed >860
TABLE 4 Tensile Strength of strip
Symbol Status Tensile Strength/MPa
R annealed <570
1/4 I 1/4hard 520-630
1/2I 1/2hard 590-770
3/4I 3/4hard 600-770
I unannealed >700
TABLE 5 Hardness of Deep Stamping Strip
State Thickness Hardness,HV
>2.5 ≤170
Deep Stamping ≤2.5 ≤165
TABLE 6 Coefficient of Linear Expansion
Heat Treatment of the Sample 20-300°C 20-400 °C 20-450 °C
Heat to temperature of 900±20℃ in the hydrogen,
hold for 1h;re-heat to 1100±20℃, hold for 15 min.;
cooled to 200℃ at a rate less than 5℃/min 4.6-5.2 5.1-5.5
Factory and facility
Why US ?
1.Specialized in manufacturing high-precision alloy for 23+ years
2.We can tailoring your unique requirements with ASTM, UNS ,GOST, standards.
3. We can produce more people cannot produce products
4. Short Lead-time
5. Leading Edge Technology
6. Good quality control in production process, ISO9001:2008, SGS, CQC, approved.
