The breakdown of the sent solid solution in magnesium alloys containing rare -earth elements largely determines the properties of these alloys [1, 2]. Plastic deformation makes changes to the nature of the decay [3].
In order to determine the influence of additional deformation on the structure and properties of a pressed alloy of type IMV7-1, rods with a diameter of 90 mm made from one swimming alloy were selected. At the same time, part of the rods was used to prepare samples for research, and the second part of the rods with a diameter of 90 mm went to press the rods with a diameter of 20 mm. In both cases, pressing was carried out at a temperature of 450 s.
It is obvious that a thin bar with a diameter of 20 mm has higher plastic properties 6, f and kcu, but inferior to the bore of the rod with a diameter of 90 mm. This difference between the mechanical properties is explained by the greater elaboration of the metal during double pressing (first up to 90 mm, then up to a diameter of 20 mm) of thin rods, as well as deforming them at a higher rate of metal during pressing, which ensured a more intense recrystallization of the metal during hot deformation.
The microstructure of hot -propressed rods of two diameters is clearly distinguished (rice. 1). In the microstructure of the bar with a diameter of 90 mm, along with recrystallized grains, strips of deformation of a cross -out, polygonized structure are observed. The bar with a diameter of 20 mm has a homogeneous, fine -grained, completely recrystallized structure. Therefore, pressed rods with a diameter of 20 mm turned out to be less hardened than rods with a diameter of 90 mm.
Studies of the influence of strengthening heat treatment on the structure and properties of the hot alloy of IMV7-1 with a diameter of the rod of 90 mm were previously carried out. In order to exclude the influence of previous deformation and output after deformation of the alloy before artificial aging, samples of pressed rods were hardened according to the 450 ° C mode, 1 hour, cooling in the air, and then aged at 200 ° C
Kinetic curves of the mechanical properties of the artificially aged alloy IMV7-1 (rice. 2) have a “step” type, characteristic.
At the same time, the preservation of sufficiently high values of plastic properties is essential: relative lengthening 5 at 10%, relative narrowing of about 22%.
