Brass

see also: Etymology of Brass

The brass is a Alliage of Cuivre and Zinc, with the very variable proportions. It often also contains other metals such as the Plomb, the tin, the Nickel, the Chrome and the Magnésium. Nickel is used in the coins or for the plating of brass, because of its resistance to the Oxydation and the Corrosion. Corrosion reveals on the surface brass a layer called Vert-de-gris.

Brass is known since prehistory, the Greeks also knew it in Antiquity. It was discovered good before zinc.

One should not confuse brass with the Bronze, which is an alloy of copper and tin, nor with the Régule, alloy of tin or lead and Antimoine.

Brass is very easy to machine but relatively fragile. One for a long time uses it for the manufacture of precision instruments, decorative elements for furniture, musical instruments, valves and fittings, etc brass is the most used alloys of copper. It is one of the principal metals used by the industry of the Décolletage (manufacture of small parts turned in very great series).

The brass boards are used in decoration for engraving and the guillochage (varnished, it become the plates on the doors of the doctors for example).

Brasses are used also basic for manufacture of the memory-shape alloys.

The Density of brass is of 8 400 kg·m^-3, its thermal Conductivité is approximately 121 W·m^-1·K^-1.

There exist three categories of brass:

simple brasses (binary): they contain only copper and zinc. The zinc addition lowers the temperature of the point melting of alloy like its electric Conductivité, but increases by it the hardness and the mechanical resistance.

brasses with lead (40 % of zinc, 1 % with 3 % of lead): lead improves workability while being disseminated in fine globules which allow a better fragmentation of the chips.

special brasses: the purpose of they are to increase the mechanical properties by the addition of alloy elements (tin, Aluminum, Arsenic, magnesium, nickel, Fer, Silicium…).

Simple: Arm

Random links: