Copper and Copper Alloy Composites

Copper Composites

A distinction is made between various composite materials in the manufacturing process:

  • Dispersion-hardened copper
  • Composite materials, that contain at least two different metals and are hardened through plating (or weld cladding), recasting, or sintering

Dispersion-hardened copper forms a copper matrix containing embedded components of one or more other materials.  Although there have been various attempts to harden copper through dispersion or fibres without decreasing the conductability, to date it has only been accomplished with fine aluminum oxide ceramic particles using the registered process called Glidcop. This dispersion-hardened copper is, through a patented inner oxidisation procedure, manufactured with a weight proportion of 0.3%, 0.5% and 1.1% aluminum oxide.  Through this inner oxidisation process, the oxide particals are distributed evening through the material.  Depending on the weight content of aluminum, the material has electrical conductivity of 78-92% compared to that of high conductivity copper and, depending on the shape, can claim up to twice the strength.  Aluminum oxide is thermally stable. Unlike copper and low-alloyed copper that soften as they near the smelting point, the composite can come very close to its smelting point without losing its form.  Thus, dispersion-hardened copper can claim a higher strength combined with high conductivity. The combination of the enhanced properties of strength, thermal stability, and conductivity makes Glidcop superior to other composites. 

Plated materials, such as steel or aluminum with one or both sides coated in copper or copper alloy, are commonly available.  Such materials are plated using a mill or through explosive welding.  An example of this technology in use are "CUPAL" conductor rails, which are copper-plated aluminum.  The weld-plating of other materials with copper materials is often performed to prevent wear and corrosion.

In copper and copper alloy castings, such as cooling pipes, the moulding are made of other metals.  In car manufacturing, belt casting technology has a technical importance with copper alloys with 10% lead and 10% tin, and 22% lead and 1,5 % tin respectively that are continually cast onto steel.  The resulting bi-metallic strip is rolled with steel backing into bearings and connectors as well as other parts needed for combustion engines.  Control discs for axial piston pumps, for example, are cast with a copper-tin alloy as a bearing material.

Additionally there are composite materials which are sinter-fused as a porous layer onto a steel strip that will later be immersed in lead, a lead-alloy, graphite, or polymer. Connectors (sleeves?) that are made out of these composites have the strength of steel and the anti-friction properties of the applied materials.