Tellurium Copper Properties
Tellurium is usually added to Copper to improve machinability (“free cutting”). ASTM (American Society for Testing and Materials) specification B301 has 0.5% Tellurium; at concentrations of up to 0.75%, machinability is improved while electrical conductivity and hot working behaviour are maintained. Mechanical properties are similar to tough pitch Copper, while machinability is similar to Brass — the alloy’s hardnesses are increased by precipitation of Copper Telluride.
This alloy is not suited to welding, although it can be welded with gas shielded arc welding or resistance welding; it can be readily soft soldered, silver soldered, or brazed. It can be used as the electrode in electrical discharge machining (EDM) — the alloy is used to replace Copper when grinding wheel loading occurs during fine finishing of the electrode – and the alloy retains the properties of Copper in the EDM process.
Tellurium Copper alloy 145 (TeCu) is considered a free-machining Copper alloy, ideal for parts that require extensive machining, corrosion resistance, or high conductivity. It produces short, clean chips that are easily removable. Tellurium Copper machines more quickly and efficiently than pure Copper.
How it can be processed
- Cold formability
- Hot formability
Tellurium Copper Applications
When a component is specified to be made from a free-machining copper, it is often dual certified. This means that either CuTeP or CuSP may be used, although CuSP may be a more cost-effective choice for certain applications.