What is an alloy? Definition

Since the dawn of time, man has never ceased to want to improve his daily life. For his needs, he has learned to use natural elements such as wood or stone. But from the discovery of metal, specific needs were created, and the material needed to satisfy them had to be sought. The alloy of metals was therefore born as a result, to meet this demand which is now vital. Today, this science continues, but to understand its objectives, it is important to know its definition.

Simple definition

The word alloy etymologically belongs to the same family as alliance and ally. Deriving from the root allier, from the Latin “alligare” which means to attach, it logically induces an idea of association or addition. The alloy of metals is thus defined simply by the association of two or more metals together, with the aim of obtaining a new element. It also happens that the alloy involves a metal and other chemical elements such as carbon (found in steel or cast iron), or silicon (found in aluminium). As the metal is generally known for its strength, the alloy can only be obtained by bringing this solid state back to the liquid state, so that it can be mixed more easily. It is then important to bring it to its melting temperature to successfully complete the alloying operation.

The different alloying structures

When metals reach their melting point, they can be combined to make a new material. However, alloying metals can lead to two quite distinct results. In the first case, we speak of a homogeneous structure. In other words, the atoms of the two components combine to form an order that can be regularly ordered or, on the contrary, random. In the opposite case, several atoms of one of the metals are placed next to a single atom of the other. In this case, it is a heterogeneous structure.

The objectives of the alloy

Each metal has its own physical properties. Some are known for their strength, others for their malleability, for example. The main purpose of alloying metals is therefore to obtain a new material with all the properties of each one. In another context, it can be intended to accentuate or cancel a physical property. This procedure generally occurs when the metal is mixed with another chemical element.

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