 |
4J29
DLX
bright
ISO9001
5kg
Industry
Product Description
Kovar Alloy 4j29 Bar is a controlled-expansion iron-nickel-cobalt alloy renowned for its exceptional thermal expansion compatibility with hard glass and ceramics. 4J29 maintains near-zero dimensional variance across extreme temperature fluctuations, establishing itself as the gold standard for hermetic sealing in critical applications. This alloy bar also exhibits outstanding resistance to thermal stress cracking and corrosion in vacuum environments.
Kovar Alloy 4j29 Bar is particularly valued for its unique thermal expansion synchrony and impermeable sealing capabilities. A defining characteristic is its engineered crystallographic structure that remains geometrically stable from cryogenic to elevated temperatures, enabling the fabrication of precision components requiring micron-level tolerance retention during thermal cycling.
Maintains near-zero differential expansion with hard glass/ceramics across -60°C to +450°C, eliminating interfacial stress-induced sealing failures.
Creates impermeable metal-to-nonmetal joints sustaining helium leak rates <10⁻⁹ Pa·m³/sec under vacuum/high pressure, ensuring lifetime sealing reliability.
Forms a dense, stable chromia (Cr₂O₃) protective layer at high temperatures, resisting oxidation in air or oxygen-containing environments.
Zero outgassing in critical vacuum environments.
Resists weak acids, alkaline vapors, and electronic cleaning agents.
Specification
| Kovar Alloy 4j29 Bar Chemical Composition | |
| Elements | 4J29 |
| Carbon (C) | 0.03 |
| Sulfur (S) | 0.02 |
| Phosphorus (P) | 0.02 |
| Manganese (Mn) | ≤0.50 |
| Silicon (Si) | ≤0.30 |
| Nickel (Ni) | 28.5-29.5 |
| Chromium (Cr) | - |
| Cobalt (Co) | 16.8-17.8 |
| Iron (Fe) | Rest |
| Other Elements | - |
| Kovar Alloy 4j29 Bar Mechanical Properties | |
| Alloy Grade | 4J29 Kovar Alloy |
| Density (g/cm³) | 8.2 |
| Tensile Strength (MPa) | 600-700 |
| Yield Strength (MPa) | 300-400 |
| Hardness (HV) | 200-250 |
Application Field
Leveraging unique thermal expansion properties and hermetic reliability, Kovar Alloy 4j29 Bars are critical in:
Microwave/laser device housings: Glass-to-metal seals for TWTs, magnetrons
Vacuum relays/switches: Ceramic-metal brazed contacts
Optoelectronic sensors: Hermetic packaging for IR detector windows
Satellite sensor modules: Pressure/temperature probes in thermal cycling
Aero-engine igniters: Ceramic-insulated sealing assemblies
Space-grade connectors: Vacuum feedthrough RF connectors
Lithography systems: Thermal-compensation substrates for wafer stages
CVD chambers: Process gas seals at elevated temperatures
Ion implanters: Vacuum feedthroughs for precision electrodes
DLX Advantage
CHANGZHOU DLX ALLOY CO, LTD was established in 2002 and has got ISO9001 International Quality Management System Certificate and SGS Certificate. Our factory is professional in researching and producing special alloy material. From melting, drawing, heat treatment, finishing and testing .We offer nickel-based, copper-based, and iron-based alloys, including super alloy, welding materials, anti-corrosion alloy, precision alloy, FeCrAl alloy, NiCr alloy, CuNi alloy, thermocouple and etc, in the form of wire, strip, ribbon, bar, tube, plate.
1.Market Leader - Top 5 in China's nonferrous metal industry
2.Flexible products - Thousands of product specifications,Meet multiple needs of buyers
3.Low MOQ - Can customize samples
4.Short production lead time，fast delivery of whole cabinet
5.Professional inspection equipment - Before delivery, we will use spectrometers, tensile testers and other professional equipment to conduct a comprehensive inspection of the products to ensure that the goods are qualified for acceptance
6.Professional business team - Quickly responds to customer inquiries,24-hour professional quotation online The salesperson will follow the customer's requirements for the use of the product,Professionally recommend more appropriate performance and price products to customers
7.Intact packaging - Packaging according to customer needs.You can customize wooden boxes to ensure that the goods arrive at the destination in good condition
8.Various payment methods - Facilitate customer payment
9.Get good reviews from customers - Old customers have long-term cooperation,The longest is more than 7 years
10.Received various awards - Google is very recognized by us,They give us awards every year
FAQ
4J29 is an iron-nickel-cobalt controlled-expansion alloy. It is used for components where thermal expansion compatibility with a selected glass or ceramic is required.
“Kovar” is a trade name commonly associated with a Fe-Ni-Co controlled-expansion alloy. Do not assume that every material described as 4J29 automatically meets a particular Kovar or ASTM specification. State the exact grade and standard required, and confirm the material documents before ordering.
It may be used in glass-to-metal sealing designs when the alloy, sealing glass, component design and process are compatible. The final seal performance must be verified for the complete assembly and application.
Available sizes depend on current stock and production capability. Send us the required diameter, length and tolerance so we can confirm the options for your order.
