Expansion Alloy Rod
Expansion Alloy Rod
  • Expansion Alloy Rod
  • Expansion Alloy Strip
    • Your Trusted Source for Precision Alloy Manufacturing

    Expansion alloys are specialized materials designed to exhibit controllable thermal expansion properties. These alloys are widely used in applications where the thermal expansion needs to match or remain stable with other materials, such as glass, ceramics, or specific industrial components, or when a specific expansion must be met over a certain temperature range.

    Available grades: 4J29, 4J32, 4J33, 4J50, 4J42

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    • Plate / Sheet
      Plate / Sheet
      Thickness: 0.1mm-50mm
      Width: 50mm-1000mm
      Length: 1000mm-6000mm
    • Strip
      Strip
      Thickness: 0.02mm-1mm
      Width: 3mm-500mm
      Delivery Forms: Bright shiny surface or anodized surface, supplied in spools or cut-to-length
    • Rod
      Rod
      Diameter: Ø3mm-Ø100mm
      Length: 100mm-2000mm
      Delivery Forms: Hot rolled, forged or turned
    • Wire
      Wire
      Diameter: Ø0.03mm-Ø6mm
      Delivery Forms: Bright shiny or anodized, supplied in spools
    • Tube
      Tube
      Outer Diameter: Ø3mm-Ø200mm
      Wall Thickness: 0.5mm-10mm
      Length: 100mm-6000mm
    Chemical Composition
    Elements 4J29 4J36
    Carbon (C) Not greater than 0.03 0.05
    Sulfur (S) 0.02 0.02
    Phosphorus (P) 0.02 0.02
    Manganese (Mn) ≤0.50 0.20-0.60
    Silicon (Si) ≤0.30 ≤0.30
    Nickel (Ni) 28.5-29.5 35.0-37.0
    Chromium (Cr) - -
    Cobalt (Co) 16.8-17.8 -
    Iron (Fe) Rest Rest
    Other Elements
    Thermal Expansion Properties
    Alloy Grade 20°C-100°C 20°C-300°C 20°C-500°C
    4J36 Invar Alloy 1.2×10⁻⁶ /°C 2.5×10⁻⁶ /°C -
    4J29 Kovar Alloy 4.6×10⁻⁶ /°C 5.5×10⁻⁶ /°C 6.2×10⁻⁶ /°C
    Mechanical Properties
    Alloy Grade 4J36 Invar Alloy 4J29 Kovar Alloy
    Density (g/cm³) 8.1 8.2
    Tensile Strength (MPa) 500-600 600-700
    Yield Strength (MPa) 250-350 300-400
    Hardness (HV) 150-200 200-250
    Electrical Properties
    Alloy Grade 4J36 Invar Alloy 4J29 Kovar Alloy
    Electrical Resistivity (10⁻⁶ Ω·cm) 80 50
    Thermal Conductivity (W/m·K) 10-12 16-18
    Features
    • Some expansion alloys, such as Invar alloys, expand almost not at all with temperature changes, while other types can be engineered to have a specific expansion rate.
    • These alloys maintain shape and size stability, even in environments with significant temperature fluctuations.
    • They typically offer enough strength and toughness, making them suitable for complex structural components.
    • They are easy to process with cold and hot working, welding, and other forming techniques.
    • Many expansion alloys also exhibit excellent corrosion resistance.
    Applications
    • Precision instruments and measuring devices: such as balances, microscopes, and laser interferometers
    • Electronics and semiconductors: integrated circuit boards, connectors, resistors, etc.
    • Aerospace: navigation systems, control systems on aircraft and satellites
    • Automotive industry: engine sensors, exhaust system components
    • Energy industry: sensitive equipment in nuclear power plants, thermal power stations, such as instrument panels and controllers
    • Watchmaking: precision components such as gears and mainsprings in high-end watches
    • Lighting industry: metal brackets and connectors in light bulbs and LED lighting fixtures
    Packaging
    • Packaging
    • Packaging
    • Packaging
    • Packaging
    • Packaging
    • Packaging
    Why Choose DLX Alloy?
      • Strict Quality Control
        Strict Quality Control
        • Raw material purity is verified through spectrographic analysis, and key production processes are monitored in real time.
        • Finished products undergo 100% inspection, with a pass rate of over 99%.
        • Products comply with applicable standards, including ASTM and GB, and have obtained ISO, TÜV, CE, RoHS, and other certifications.
      • Reliable Delivery
        Reliable Delivery

        Small-batch orders are delivered within 10–30 days, while large-volume orders usually take around 60 days, helping ensure on-time delivery.

      • Customization and Sample Support
        Customization and Sample Support
        • With over 20 years of industry experience, DLX Alloy provides customized alloy solutions, adjusting material specifications and chemical compositions according to customer requirements and offering professional technical support.
        • Standard and custom are available for fast prototyping, with standard samples ready in 7–10 days.
        • Sample testing supports small-batch testing and validation, helping customers verify material performance through actual test data and reduce trial-and-error costs during R&D.
    Our Expansion Alloy