Technical Information - cold rolled Copper Foils and Copper Strips CW020A

Basic information and applications CW020A

With a copper content of at least 99.95% and a low oxygen and phosphorus content, the alloy CW020A is of higher quality than the commonly used types of copper E-Cu (UNS D11000) and SF-Cu (UNS C12200).

This material is used in general electrical engineering such as cable straps and connectors, transformer coils, semiconductor carriers and stamped and bent parts (e.g. for seals).

Further application examples: heat dissipation plates and heat exchangers as well as vacuum technology.

The material is not approved as a spring material. Brass or bronze should be used for springs and copper-beryllium should be used for very high spring forces.

If there are high purity requirements, the material 2.00 = OFE copper with a copper content of at least 99.99% should be used.

Delivery condition

Structure: cold rolled, not hardenable

Surface: no information available

Tensile strength: approx. 360 N/mm² (with a thickness of 0.50mm only >300N/mm²)

Tolerances

Thickness tolerance*: +/- 10%

Width tolerance*: -0 / + 0.40mm

Straightness: normal

Flatness*: wave height max. 1.0 mm

*Information applies to cold-rolled copper foils and copper strips 2.0070

Mechanical details

Yield strength Rp0.2: > 320 N / mm²

Elongation A 50: > 2%

Hardness: at least 110 HV

With good edge processing after cutting (e.g. by surface grinding) the following values ​​can be achieved:

Alternating bending stress (medium stress = 0):

The bending fatigue strength is defined as the maximum bending stress amplitude at which a material can withstand 10 ⁷ load cycles under symmetrical alternating load without breaking. It depends on the tested strength condition and is about 30% of the tensile strength Rm.

Tension threshold stress (minimum stress = 0):

No information possible

Because the fatigue strength depends on various factors such as the ambient conditions and the edge properties, no values ​​can be guaranteed.

In the case of heavy loads or bends that are not perpendicular to the rolling direction, the use of spring materials such as bronze or copper beryllium is required.

Alloy Designations

Material - Composition*

* for the exact composition can be documented in the form of a test certificate 2.2 or 3.1 (according to DIN 10 204) for each batch.

Physical Information

Processing information CW020A

Punching: The cutting gap should correspond to approximately 10% of the strip thickness. The corner radii should be at least 0.25 and the punch diameter at least twice the tape thickness.

Laser cutting: Due to the high thermal conductivity of copper, this material can only be laser cut moderately.

Etching: SE-Cu is very easy to etch.

Bending: Soft versions of copper can be easily bent with a bending radius of 0. In the hard-rolled version available from us, the minimum bending radius should not be less than 1 x strip thickness.

Surface grinding: Since copper cannot be magnetized, it cannot be clamped on magnetic chucks of grinding machines.

Welding & Soldering: The material is well suited for inert gas welding and medium-sized for laser welding. Resistance welding should be avoided. However, the heat input at the weld seam can lead to a structural change that reduces the strength.

Copper can be soldered very well.

Chemical resistance CW020A

Resistant to: industrial atmosphere (formation of dark or green protective layers), industrial and drinking water (max. Flow speed approx. 1.5-2 m / s), pure water vapor, non-oxidizing acids, alkalis (with the exception of ammoniacal and cyanide-containing compounds), neutral salt solutions.
Not resistant to: oxidizing acids, moist ammonia and halogen-containing gases, hydrogen sulfide, sea water, especially at high flow rates.

Important NOTE

The technical information listed above or the information provided on the nature or use of the materials serve for description and are not a guarantee of properties. The information with which we want to advise you corresponds to our experience and that of our upstream suppliers. We cannot guarantee the results of processing and application. (03/2024)