INVESTIGATING THE PROCESS OF HOT EXTRUSION OF REINFORCED HIGH-STRENGTH ALUMINUM CAST ALLOYS AND PECULIARITIES OF THEIR STRUCTURE FORMATION AND PROPERTIES

Abstract

At creating new materials with functional properties, metal-based composite materials, which are solid-proof and dispersed with grain particles (fixed) and reinforced with metal fibers are of great interest. At that, the dimensions of the disperse particles (phase) vary from

0.01 to 0.1 micrometres, the volumetric content is from 1 to 15 wt. %, and the size of the dispersed grain exceeds 1.0 mcm., the volumetric content is ~ 25 wt. %, whereas the diameter of the metal fibers varies from one to several tens and one hundred micrometers, and the volumetric content is from several to about 70 wt. % and more.

The tensile state of hot extraction of reinforced aluminum cast alloys are studied and the peculiarities of the structure formation and properties are studied.

It is shown that all the forces and voltages change during the process, depending on the speed and deformation conditions at the initial and subsequent stages of the process, the physical condition of the metal and the metal contact surface of the container.

The main standards that determine the nature of deformation at hot extrusion with one passage conical pipeline are established. It has been revealed that during direct compression, the structure is inhomogeneous, and the boundary of strength increases from the center to the surface and from the front to the press. In the case of not high extrusion coefficients, the difference of mechanical properties between the central and the surface layers of the press increases, but in the case of high extrusion coefficients, this difference sharply decreases and often totally dissapears, which is conditioned by the reduction of intensities of the mechanical properties in the case of large extrusion factors in metals and alloys.