Aluminium castingAluminum does not have polymer transformations and crystallizes in a face-centered cubic lattice. The extensive use of aluminum is due to its low density, high ductility, and therefore ability to handle pressure, and high corrosion resistance. Aluminum is quickly covered with an oxide film, preventing the penetration of aggressive agents to the base metal.
Because of the wide variety of properties, aluminum alloys have received very widespread in the aircraft industry. All aluminum alloys are divided into wrought, casting, and sintered powder.
Wrought aluminum alloys have good ductility. Of those, rods, tubes, sheets, profiles of various sections, wire, forgings, and stampings are produced. For the manufacture of parts and semi-finished products using various methods of forming are used: pressing, forging, hot stamping, bending, rolling, drawing. The plastic deformation is also used for hardening aluminum alloys, as this forms anisotropy of properties. All aluminum alloys can be welded in various ways. In the field of welding, anisotropy of properties is eliminated.
The chemical composition of wrought aluminum alloys is divided into groups that are built on the presence of the main elements included in the chemical composition of the alloys. Casting aluminum alloys in a separate class of alloys, since they share the presence of the basic properties: the fluidity of liquid, bulk and casting shrinkage, and the tendency to form shrinkage cracks and segregation.
There are two classes of aluminum alloys, shared on the basis of the effect of heat treatment on non- strengthening and strengthening heat treatment. These alloys are widely used in the aircraft industry.
Non-strengthening by the heat treatment aluminum alloys create systems based on Al - Mg and Al - Mn. In the structure of these alloys, the solubility of the components in the aluminum does not change and phase transformations during heating and exposure do not occur. Strengthening heat treatment aluminum alloys is the most widely used class of alloys.