Heat Treatment of Non-Ferrous Metal Alloys
Non-ferrous metals are malleable and ductile materials that are used in a variety of applications due to their desired mechanical and electrical properties. Heat treatment is an important process step in the manufacture of many non-ferrous metal alloys. Heat treatment is characterized by an increase in temperature over a specified period in order to undergo structural change. These structural changes are beneficial in giving the non-ferrous materials increased hardness and resistance to corrosion among other desirable properties.
Before heat treatment can be successfully carried out, the material must first be heated almost to its melting point, depending on the desired mechanical properties. It is important to note that all non-ferrous metals have a different melting point than ferrous metals due to their different compositions. This temperature must be carefully maintained in order to first obtain annealing.
Annealing is a very important process in heat treating non-ferrous metals. This process is used to remove stresses within the metal and to make additional heating processes easier. It also increases the metal’s plasticity, toughness and ductility. The most common way to anneal non-ferrous metals is to heat them until they reach their critical transformation temperature and then slowly cool them, which can be done naturally or through forced cooling. The cooling rate is dependent upon the alloy, however temperatures ranging from 500-700 degrees Celsius can be used for most aluminum alloys.
The next process used in the heat treatment of non-ferrous metals is stress-relieving. This process helps the material to be able to undergo additional heating or hardening processes that will increase its strength and durability. Depending on the metal or alloy, this process can either be a heated holding process or a cooling process which allows the metal to slowly reach ambient temperature.
The following process in non-ferrous metal heat treatment is tempering. This process helps to reduce the metals brittleness and increase its plasticity and elongation capacity. This occurs during the cooling process, and in order to control the properties of the metal the amount of cooling that is applied must be adjusted accordingly. The tempering process is typically employed with steel alloys, but it can also be used with other non-ferrous metals such as aluminum and titanium.
The last step of the heat treating process is to quench the material. Quenching is used to harden the material, as well as reduce its size to give it better shape control. Quenching is typically done with water or oil, depending on the material and its desired properties, which cools the material quickly. This rapid cooling process helps to improve the wear and abrasion resistance of the metal, as well as improve its tensile strength.
In conclusion, heat treatment is an important process that is used to improve the properties and extend the life of non-ferrous materials. It is important to understand the different processes and their effects on the material in order to successfully heat treat the material to its desired properties.
