What is an alloy

Goldsmith Plaar

Most often, alloys are made by fusing the components together. Sometimes, however, they also arise through the joint reduction of mixed ores, for example in the production of brass in ancient times, which was extracted from zinc-containing copper ores long before zinc was discovered.

In the solid state, an alloy can be produced by so-called sintering. Metals are pressed together under high pressure and heated up strongly. At the same time, the metals do not liquefy. The high temperatures and the close physical contact mean that an exchange of atoms takes place between the lattices of the metals. This process is also known as diffusion.

Alloys are of great technical importance

In technology, alloys are fundamentally more important than pure metals. Their number is probably several hundred thousand. In the case of alloys, it is particularly important that their properties can be precisely determined through the choice of components. The changeable properties are e.g. hardness, elasticity, brittleness. This gives you enormous advantages over pure metals.
In the case of the alloys of precious metals, changes in mechanical and optical properties play a role. Nowadays, however, the lowering of the price by adding cheaper metals plays an essential role. At the same time, the density always decreases.
An article about various common alloys for jewelry can be found here.
Alloys have also played a role in the extraction of gold. The term amalgamation can also be found in an article on gold mining. These are all alloys with a compound of mercury, which are usually poisonous.