 |
          |
| The term “copper” is used to describe commercially
pure copper (as opposed to copper alloys such as brass). Pure copper is
extremely ductile but It has a low intrinsic strength, this can however
be increased by work hardening. The most popular attribute of copper is
its electrical conductivity and it finds many applications in electrical
engineering. The basics Copper forms the basis of number of very useful alloys (brass, bronze etc) however, remains an extremely useful metal in its own right. Copper has a superior electrical conductivity to all metals other than silver and it has a very high thermal conductivity too. It can be worked very easily making it the material of choice for many applications. Its ability to form a protective oxide film with an attractive green patina has also made it the material of choice for many constructional applications, particularly roofing. Example of copper roofs can be seen throughout Britain today. In its naturally ‘pure’ state there is always some degree of impurity. The high conductivity pure copper used for the production of bus-bars etc. is, as a rule, 99.9% minimum pure, the impurities being silver and oxygen. These impurities do have their drawbacks. The oxygen content causes an adverse reaction at high temperature, and this makes operations such as welding more difficult, and so phosphorus is often added to de-oxidise the copper, making it more suitable for applications where brazing or welding is involved. The softness of ‘commercially pure’ copper makes it a difficult metal to machine. Of course, in it’s more highly alloyed state (particularly with the addition of zinc and lead to form free cutting brass, against which almost all other metals are indexed for their machinability) this is not a problem, but to retain the higher conductivity of copper or its aesthetic appearance, the addition of sulphur gives a greatly increased cutting ability, to as high as 80% on the machinability index. Alloy specifications The system described products in two ways, one using symbols the other using numbers. The symbol system follows the ISO compositional system and a brass made up of a 63/37 ratio of copper and zinc is shown as CuZn37. The numbering system is six-character alpha numeric system with two characters (the first of which will be ‘C’ for copper) followed by three numbers and a letter. Using this system C101 has become CW004.with the W denoting that this is a wrought product. This catalogue displays the old and the new systems (including the symbol based new method). Alloy selection
|
|
| © 2007 Smiths Metal Centres Ltd |
| Terms & Conditions | Privacy | Disclaimer | Contact | |
