What is the heat treatment of materials?

The heat treatment of a material (whether it is a use of heat or cold) is intended to modify its properties. Most often, it is a matter of modifying the resistance of metals in order to have new practical applications. Different materials are concerned, including wood, glass, metal and food. For each of them the technique used is different and the applications are also made.

**Principle of heat treatment**

Thanks to the heat treatment of the materials, it is possible to modify their initial molecular structures. This has a direct impact on the shape and strength of these materials, at least at their atomic level. Thermal treatment of wood Thanks to the heat treatment, it is possible to make the wood darker and to give it a more homogeneous appearance. In general, the treated wood becomes more stable. It also becomes more resistant to fungi in the case where it is carried beyond a certain temperature. However, this latter process is done to the detriment of its resistance and its appearance. Thermal treatment of glass By cooking the glass, it is possible to reinforce it to prevent it from breaking too easily. Treatment of steel This is an even more specific treatment because it will be a question of transforming the metal by alternating heating and cooling cycles. By this process, better mechanical properties are obtained from the treated metal such as steel strength, elasticity and its ductility (plastic deformability) is improved.

**The different treatments**

Ductile materials These materials which can be deformed are treated in cases where it is necessary to give them a particular shape. For example, if you want to make a horseshoe. The disorganization of the atoms will harden the object once it has cooled (hardening). By heating less (method of annealing), the atoms are mobile and the softened material eliminates its defects. Precipitates With the precipitates, an important hardness of the metals is obtained. They form with slow cooling. With rapid cooling (quenching) via a gas such as nitrogen, for example, the atoms remain in solution. Here again, with lower heating, the atoms are mobile and this method is used for alloys (aluminum for example) which possess high elastic capacities.