SU1338977A1 - Method of hot briquetting of pellets from aluminium alloys - Google Patents

Abstract

The invention relates to powder metallurgy, in particular to the processing of metals by pressure with welding during plastic deformation. The goal is to increase the mechanical properties. In the method of hot briquetting of aluminum alloy pellets, heated pellets are poured into a container and compacted them in the direction of the briquette axis at a temperature of 0.85 - 0.9 melting points and strain rates of 10 - 10 s. 1 tab. OO from 00 (X vj vj

Description

113

This invention relates to yoroshko. metallurgy, in particular to metal forming with welding in the process of plastic deformation.

The aim of the invention is to increase the mechanical-PROPERTIES of the briquettes. At high strain rates (10 - s and higher), the setting occurs only in some areas of the contact of the granules. Further development of the interaction does not occur and micropores remain between the granules, which cause low mechanical properties of the briquettes. At very low deformation rates (10

10 s and below) the duration of the briquetting process increases dramatically, the welding time is measured in tens of minutes. There is a slight decrease in the mechanical properties of the briquette. Briquetting under optimal conditions (- с) is accompanied by intensification of such important processes from the point of view of welding as the movement of structural defects, intergranular grain, diffusion, etc. This requires less energy to be consumed than under normal deformation conditions. The intensification of diffusion processes to heal the discontinuities arising from the mutual displacement of the grains, as well as the discontinuities that occur on the contact surface of the gran ul during joint plastic deformation during briquetting, leads to a high-quality graining of the granules and, consequently, to an increase in the mechanical properties of the briquette.

Example. Briquetted alloy CAC, -1. Briquetting is carried out on a vertical hydraulic press with a force of 1 MN, in a container with a diameter of 34.5 mm. Poan travel speed

Sona during briquetting is determined from the expression

z z-h, where is the strain rate;

h - the current height of the briquette.

The deformation rate during the briquetting process is kept constant, for which the speed of movement of the punch is reduced.

The table presents the results of mechanical testing of samples (temporary tensile strength Cg and

relative elongation S) cut from briquettes obtained from granules of the CAC-1 alloy at various temperature and speed parameters according to the proposed and known methods.

From the data in the table it can be seen that the proposed method of briquetting allows to increase the strength indicators (temporary tensile strength) by 2–8%, the ductility parameters (relative elongation) by 10–30%,

Thus, the proposed method, in comparison with the known, allows to increase the mechanical properties of briquettes, especially plasticity indicators, which makes it possible to use them as a blank for subsequent stamping.

Claims (1)

Invention Formula The method of hot briquetting of aluminum alloy granules, including placing the heated granules into a container and compacting them in the direction of the briquette axis, which, in order to give mechanical properties, compaction is carried out at a temperature of 0.85 - 0.9 melting point and speeds deformat-mats and 10-10- s-.