One of the most important properties of an aluminum alloy when production of aluminum profiles is its so-called compressibility. It is determined by the maximum permissible speed of pressing profiles. It is the compressibility of the alloy that is one of the most important factors., which determine the cost and efficiency of the entire production process of aluminum profiles. It is known, that the temperature and speed parameters together with the stress state in the deformation zone, mostly in the matrix, play a significant role in increasing the compressibility of a particular aluminum alloy.
The measure of compressibility is the maximum pressing speed without cracking., tears or other surface defects. By the value of the compressibility of an aluminum alloy, besides its chemical composition, influenced by various technological parameters, for example, modes of homogenization of ingots (pillars), method of heating blanks, design and condition of the matrix, etc..
Hard and soft aluminum alloys
According to the difficulty of pressing, all aluminum alloys for the manufacture of aluminum profiles are divided into three groups (table 1): easy and difficult to compress ("soft" and "hard"), as well as an intermediate group of alloys, pressed with medium difficulty ("semi-hard").
Soft alloys aluminum alloys
Soft and semi-hard aluminum alloys are united by, that they are manufactured using similar technology and using the same equipment: joint-to-joint direct pressing, hardening (cooling) on the press, use of a similar pressing tool. Compression rating – relative compressibility – some soft and semi-hard aluminum alloys are presented in the table 2.
Solid aluminum alloys
Hard aluminum alloys extruded as straight, and back pressing: for each pressing, one piece, hardening of aluminum profiles is carried out with separate heating. The relative compressibility of some hard aluminum alloys is shown in the table 3. See more Compressibility aluminum alloys.
A source: Saha P.