OF-Cu Copper

Designation

OF-Cu (Oxygen-Free Copper)
Alternate names: C11000 (ASTM), Cu-OF (EN), 2.0040 (DIN 1708)

Key Features

1. Ultra-High Purity: Copper content ≥99.95%, oxygen ≤0.06%, with minimal impurities.

2. Exceptional Conductivity: Electrical conductivity ≥100% IACS, second only to silver, ideal for high-precision electrical components.

3. High Thermal Conductivity: Thermal conductivity ≥391 W/(m·K), excellent heat dissipation.

4. Corrosion Resistance: Resistant to atmospheric corrosion but susceptible to hydrogen embrittlement in high-temperature reducing atmospheres.

5. Workability: Suitable for cold/hot working (wire drawing, forging, stamping), weldable, and brazeable.

Product Forms & Specifications

Form	Specifications
Copper Rod	Diameter: 3mm–150mm; Length: 1000mm–6000mm
Copper Tube	OD: 5mm–200mm; Wall Thickness: 0.5mm–10mm
Copper Sheet/Strip	Thickness: 0.1mm–50mm; Width: 100mm–1200mm
Copper Wire	Diameter: 0.05mm–10mm; Custom spool lengths
Copper Foil	Thickness: 0.005mm–0.1mm; Width: 10mm–500mm
Custom Profiles	Tailored to drawings (e.g., lead frames, terminals)

Chemical Composition

Element	Cu	O	Total Impurities
Content	≥99.95%	≤0.06%	≤0.05%
Note: Typical impurity limits (%): Pb≤0.005, Fe≤0.005, S≤0.005, Bi≤0.001

Physical Properties

Property	Value
Density	8.94 g/cm³
Melting Point	1083°C
Thermal Conductivity (20°C)	391 W/(m·K)
Electrical Conductivity (20°C)	101–102% IACS
Resistivity (20°C)	1.673×10⁻⁸ Ω·m
Thermal Expansion Coefficient	16.5×10⁻⁶/K (20–300°C)

Mechanical Properties

Condition	Tensile Strength (MPa)	Yield Strength (MPa)	Elongation (%)	Hardness (HV)
Soft State	200–250	60–80	≥40	35–45
Hard State	350–420	330–380	2–8	85–95
Note: Hard state data based on cold-working processes.

Core Advantages

1. High Purity & Conductivity: Ensures zero signal interference in high-end electronics.

2. High-Temperature Stability: Withstands 920°C brazing in hydrogen environments (requires O₂ ≤0.03%).

3. Low Gas Emission: Ideal for vacuum devices (e.g., magnetrons, traveling wave tubes).

Applications

• Electronics: IC lead frames, vacuum switch contacts, superconducting magnet stabilizers.

• Power Transmission: Busbars, cables, transformer windings.

• Aerospace: Rocket engine cooling ducts, satellite waveguide components.

• Vacuum Devices: High-power transmitter tubes, vacuum capacitors.

Processing Guidelines

1. Cold Working:

Anneal at 500–700°C (under protective atmosphere) to relieve stress.

2. Hot Working:

Hot-rolling temperature range: 750–875°C; avoid oxidation.

3. Welding:

Avoid welding in reducing atmospheres >370°C to prevent hydrogen embrittlement.

4. Surface Treatment:

Use sulfuric acid + hydrogen peroxide for pickling; avoid nitric acid.

Key Application Scenarios

Industry	Typical Components	Performance Requirements
Electrovacuum	Magnetrons, vacuum capacitor brazes	High-temperature H₂ resistance, low gas release
New Energy	EV charging pile terminals	High current capacity, arc erosion resistance
Medical Equipment	MRI coils, electrosurgical tools	Non-magnetic interference, signal fidelity

FAQ

Q1: How does OF-Cu differ from regular copper?

A1: OF-Cu has lower oxygen (≤0.06% vs. ≤0.1% in regular copper), higher conductivity, and reduced hydrogen embrittlement risk.

Q2: How to avoid hydrogen embrittlement?

A2: Control oxygen content ≤0.03% and avoid high-temperature H₂ exposure during processing.

Q3: Heat treatment specifications?

A3: Anneal at 500–700°C; hot work at 750–875°C.

Standards Reference

Standard	Code	Scope
Germany	DIN 1708-1973	Chemical composition, material codes
China	GB/T 5231-2020	Classification & properties of wrought copper
USA	ASTM B152/B152M-21	Technical requirements for sheet/strip/foil

Note: Actual parameters may vary due to production processes or heat treatment. Refer to factory test reports for precise specifications.