Tolyatti State University, Tolyatti, Russia

A. I. Kovtunov, Professor of the Chair for Welding, Material Processing and Related Processes, Doctor of Technical Sciences, e-mail: akovtunov@rambler.ru
Yu. Yu. Khokhlov, Head of the Laboratory of the Chair for Welding, Material Processing and Related Processes
P. N. Selyanin, Senior Teacher of the Chair for Welding, Material Processing and Related Processes

Foamed metals, most often aluminum foam, are increasingly used in industry due to their low density, high damping properties, and ability to absorb acoustic and electromagnetic oscillations. A promising material is porous magnesium, which, compared to aluminum, has a lower density and higher damping properties. It is also used in medicine due to its good biocompatibility and mechanical properties similar to those of native bone. The production of castings from porous magnesium by filtering the liquid melt through soluble granules and then dissolving them in water has significant limitations on the thickness of resulting products and pore sizes. Due to the intense heat removal into the granular filling during gravity pouring of magnesium melt, it is not possible to obtain porous castings with a pore size of less than 4 mm. To reduce the pore size and increase the thickness of the resulting porous magnesium castings, it is proposed to conduct preliminary vacuum degassing the mold with granules before pouring. In the course of studying the processes of impregnation of a mold with watersoluble granules, it was found that preliminary vacuuming is an effective method of increasing the depth of impregnation when forming porous castings from magnesium and magnesium alloys. Vacuuming provides an increase in the rate of filtration of magnesium melt through the granular filling of the mold and enables an almost 10-fold increase in the thickness of the resulting porous magnesium products depending on the vacuum level, as well as production of porous magnesium castings with a pore size of up to 1 mm, which is 4 times smaller than the pore size of magnesium castings, obtained by gravity filling.
The work was carried out with financial support from the Ministry of Education and Science of the Russian Federation within the framework of state assignment No. 075-03-2023-260 (FEMR-2023-0003).

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