El templado es un tratamiento que se emplea para incrementar la dureza de las aleaciones de hierro. Es también una técnica para aumentar la dureza del vidrio. Para los metales, temple se realiza generalmente después de endurecer, para aumentar la dureza, y se realiza calentando el metal a una temperatura mucho más baja que la utilizada para el endurecimiento. La temperatura exacta determina cuanto se reduce la dureza, y depende tanto de la composición específica de la aleación como de las propiedades deseadas en el producto terminado. Por ejemplo, las herramientas muy duras a menudo se templan a bajas temperaturas, mientras que los resortes se templan a temperaturas mucho más altas. En vidrio, el templado se realiza calentando el vidrio y luego enfriando rápidamente la superficie, para aumentar la dureza.

Leer el artículo completo en Wikipedia · CC-BY-SA

In materials science, quenching is the rapid cooling of a workpiece to obtain certain material properties. A type of heat treating, quenching prevents undesired low-temperature processes, such as phase transformations, from occurring. It does this by reducing the window of time during which these undesired reactions are both thermodynamically favorable, and kinetically accessible; for instance, quenching can reduce the crystal grain size of both metallic and plastic materials, increasing their hardness. In metallurgy, quenching is most commonly used to harden steel by introducing martensite, in which case the steel must be rapidly cooled through its eutectoid point, the temperature at which austenite becomes unstable. In steel alloyed with metals such as nickel and manganese, the eutectoid temperature becomes much lower, but the kinetic barriers to phase transformation remain the same. This allows quenching to start at a lower temperature, making the process much easier. High speed steel also has added tungsten, which serves to raise kinetic barriers and give the illusion that the material has been cooled more rapidly than it really has. Even cooling such alloys slowly in air has most of the desired effects of quenching. Extremely rapid cooling can prevent the formation of all crystal structure, resulting in amorphous metal or "metallic glass". If the percentage of carbon is less than 0.4 percent, quenching is not possible.

Leer el artículo completo en Wikipedia · CC-BY-SA