Aluminum Heat Treating
Aluminum heat treating is a process that is used to harden or soften aluminum by heating or cooling it until it reaches the desired level of hardness. Heat treating is an energy-intensive process. In aluminum, the structure and composition of the grains, or crystallites, determines the overall mechanical qualities of the metal. This internal atomic structure changes when it is heated; this in turn changes the metal's mechanical behavior.
Aluminum is valued for its light weight and its resistance to corrosion. Because of these characteristics, aluminum and aluminum alloys are especially important to the aerospace, automotive, and other transportation industries. These industries require many different shapes of aluminum that can be achieved through heat treating.
Many different kinds of equipment are used in the heat treating process. Some of these tools include furnaces, torches, salt bathes, heating blankets, and lasers.
Several important techniques are used in the heat treating process, including annealing, quenching, and tempering. Annealing is a process by which a metal is heated and then cooled very slowly, leaving the metal soft and ductile. Quenching refers to the rapid cooling of metal and it can be used to increase the strength of metal. Tempering, in contrast, is performed to strengthen stainless steel. During the tempering process, the metal is heated to extreme heat, between 400 and 600 degrees Celsius, and maintained at this temperature until the carbon diffuses to produce bainite or pearlite.