MECHANICAL PROPERTIES OF BILLETS PRODUCED BY HOT EXTRUSION OF MAGNESIUM CHIPS

The process of billets producing from the magnesium alloy chip MA5 by hot extrusion was studied and realized. The process was realized at heating temperatures of 300, 350 and 400°C with average extrusion coefficients of 9, 13 and 24. In the process of hot extrusion occurred compaction in the matrix of blanks produced by cold pressing of chip particles; destruction of oxide films on the surface and distribution throughout the volume of the workpiece dispersed oxide particles during the plastic flow of the material through the die. As a result of the processes of recrystallization and deformation hardening, the intensity of which was determined by the temperatures and the coefficients of extraction, the structure of the material was formed. It is found that the degree of plastic deformation and the temperature of the extrusion process have an ambiguous effect on the mechanical properties of the workpieces in static tests for tension and compression, a certain role is played by the residual porosity. The strength characteristics of the obtained billets are slightly higher than the strength of the deformed cast billets from the MA5 alloy, however, lower in plasticity.