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CuNi44 Flat Wire (ASTM C71500/DIN CuNi44) Nickel-Copper Alloy for Electrical Components
Product Description
CuNi44 Flat Wire
Product Advantages and Grade Distinctions
CuNi44 flat wire stands out for its exceptional electrical resistance stability and mechanical workability, making it a superior choice for precision electrical components. Compared to similar copper-nickel alloys like CuNi10 (Constantan) and CuNi30, CuNi44 offers a higher resistivity (49 μΩ·cm vs. 45 μΩ·cm for CuNi30) and a lower temperature coefficient of resistance (TCR), ensuring minimal resistance drift in temperature-fluctuating environments. Unlike CuNi10, which excels in thermocouple applications, CuNi44’s balanced combination of formability and resistance stability makes it ideal for high-precision resistors, strain gauges, and current shunts. Its flat cross-section design further enhances heat dissipation and contact uniformity compared to round wires, reducing hot spots in high-current applications.
Standard Designations
- Alloy Grade: CuNi44 (Copper-Nickel 44)
- UNS Number: C71500
- DIN Standard: DIN 17664
- ASTM Standard: ASTM B122
Key Features
- Superior Resistance Stability: TCR of ±40 ppm/°C (-50°C to 150°C), outperforming CuNi30 (±50 ppm/°C) in precision applications.
- High Resistivity: 49 ± 2 μΩ·cm at 20°C, ensuring efficient current control in compact designs.
- Flat Profile Benefits: Increased surface area for better heat dissipation; improved contact with substrates in resistor manufacturing.
- Excellent Formability: Can be rolled to tight dimensional tolerances (thickness 0.05mm–0.5mm, width 0.2mm–10mm) with consistent mechanical properties.
- Corrosion Resistance: Resists atmospheric corrosion and freshwater exposure, suitable for harsh industrial environments.
Technical Specifications
|
Attribute
|
Value
|
|
Thickness Range
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0.05mm – 0.5mm
|
|
Width Range
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0.2mm – 10mm
|
|
Thickness Tolerance
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±0.001mm (≤0.1mm); ±0.002mm (>0.1mm)
|
|
Width Tolerance
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±0.02mm
|
|
Aspect Ratio (Width:Thickness)
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2:1 – 20:1 (custom ratios available)
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|
Tensile Strength
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450 – 550 MPa (annealed)
|
|
Elongation
|
≥20% (annealed)
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|
Hardness (HV)
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130 – 170 (annealed); 210 – 260 (half-hard)
|
Chemical Composition (Typical, %)
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Element
|
Content (%)
|
|
Nickel (Ni)
|
43.0 – 45.0
|
|
Copper (Cu)
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Balance (55.0 – 57.0)
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|
Iron (Fe)
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≤0.5
|
|
Manganese (Mn)
|
≤1.0
|
|
Silicon (Si)
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≤0.1
|
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Carbon (C)
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≤0.05
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Product Specifications
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Item
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Specification
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Surface Finish
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Bright annealed (Ra ≤0.2μm)
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Supply Form
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Continuous rolls (50m – 300m) or cut lengths
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Packaging
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Vacuum-sealed with anti-oxidation paper; plastic spools
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Processing Options
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Custom slitting, annealing, or insulation coating
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Compliance
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RoHS, REACH certified; material test reports available
|
Typical Applications
- Precision wirewound resistors and current shunts
- Strain gauge grids and load cells
- Heating elements in medical devices
- EMI shielding in high-frequency circuits
- Electrical contacts in automotive sensors
We provide tailored solutions for specific dimensional requirements. Free samples (1m lengths) and comparative performance data with CuNi30/CuNi10 are available upon request.
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