ABSTRACT
Copper has many applications, both as pure metal and an alloy base metal. It is malleable and ductile metal and can be easily rolled, drawn or forged. The tensile strength and hardness of copper can be improved by cold working although the ductility is reduced. Conversely, the annealing can improve the ductility at the expense of the tensile strength and hardness. The importance of copper is due mainly to its very high coefcient of electrical conductivity. The metal also has very good thermal conductivity and corrosion resistance. The impurities present in copper can have serious effects upon the properties of the metal. The electrical conductivity is reduced by 25% due to the presence of 0.04% phosphorus. Although the addition of 1% Cd improves the strength when used in telephone wires, it has minimal effect on the electrical conductivity. Copper is rapidly attacked by sulphuric acid, hydrochloric acid, nitric acid, ammonia, sodium hydroxide, potassium hydroxide and amines. Copper can be safely used with sulphurous acid (in paper industry); neutral salts, for example sodium chloride; hydrocarbons; alcohols; acetic acid; aldehydes; ketones; ethers and lactic and tannic acid.
