Are You Copper And Tellurium

In 1782, something very interesting was discovered in Transylvania. And it wasn't a new species of bloodthirsty vampire!

Franz Joseph Müller von Reichenstein, Main Inspector of Mines, Smelters and Saltworks in Transylvania, discovered and extracted a new metal from an ore of gilt. In 1798 it was given the name Tellurium.

Tellurium is primarily used every bit an alloying agent. It's added to lead to increase its forcefulness and resistance to sulphuric acrid, and to stainless steel to get in easier to machine and mill. But information technology's biggest role is in copper-tellurium alloys.

When did copper-tellurium alloys first appear in standards?

In 1962, CuTeP (C109) appeared in the British Standard BS 2874:1962 Rod for Free Machining Purposes. Nine years later it appeared in BS 2873:1969 Wire for General Purposes. In European Standards, CuTeP (CW118C) showtime appeared in PD 6641:1999 Copper and Copper Alloys - Compendium of Compositions and Products.

Why add tellurium to copper?

A copper-tellurium alloy is called a "costless machining alloy". This is an alloy that, when subjected to machining operations, consumes lower power, gives better surface finish, produces small metallic fries, and results in longer tool life.

The machinability of a material – the relative ease or difficulty with which it can be machined – is measured past its machinability index. Engineers wait at machinability index when selecting a tool material or machine speed for operations such as metal cut or grinding.

On a machinability index scale with 100% equal to free-machining contumely, copper-tellurium alloys come in around 85-90%, compared to pure copper which has a machinability index of approximately 20%. This makes copper-tellurium alloys superior to pure copper in applications requiring products to be drilled, turned or machined, where they lead to increased efficiency on manual and automatic production lines likewise equally a significantly longer tool life.

In addition, the surface finish of these alloys is superior to that of pure copper. A expert surface end is important in plating and soldering and in MIG (Metal Inert Gas) welding nozzles, as a smooth surface resists spatter build-up.

Why are they piece of cake to machine?

The reason for the skilful machinability of copper-tellurium alloys is their microstructure. Tiny particles of Cu₂Te deed as chip breakers leading to brusk chips, which fly off quickly, assuasive a much college machining speed than is possible with pure copper and resulting in a more cost-constructive product for the designer.

Other favourable backdrop

Copper-tellurium alloys display loftier thermal and electrical electrical conductivity (IACS of 93–94%), resistance to hydrogen embrittlement (leading to easy soldering and brazing), good resistance to atmospheric corrosion, and resistance to softening.

Applications

The combination of fantabulous machinability, piece of cake forming, expert corrosion resistance and loftier electrical and thermal conductivity makes copper-tellurium alloys ideal for a range of applications.

Copper-tellurium alloys are ideal for repetitive machining applications at high rates

A good instance is the nozzle tip for a MIG welding gun. Metallic inert gas (MIG) welding is a welding procedure in which an electric arc forms between a consumable wire electrode and the workpiece. The arc heats the metals, causing them to cook and join. The nozzle tip transmits electrical energy to the electrode which passes through it and directs it to the weld area. It must be very accurately machined since it must permit the electrode to pass while maintaining electrical contact. In add-on, the polish surface of the tip resists spatter build-upwardly. This is why copper-tellurium is ideal for this application.

Other applications include relay parts, electrical switches, circuit breaker terminals, electrical connectors, transistor bases, bolts, studs, magnetron bodies and coolers, plasma cutting electrodes and nozzles, and laser nozzles.

Available forms

Copper-tellurium alloys are available as hollow rod, hexagonal, circular and square rod, tube and wire. Profiles may exist bachelor on request to the manufacturers.

Want to know more than most copper-tellurium alloys?

Consult the copper-tellurium alloys page in Copper Development Association's Copper Electrical conductivity Materials Database.

High voltage copper-tellurium pin bodies (Courtesy of KME Deutschland).