Mechanical properties of intermetallic alloys of the Fe – Al system obtained by a combined process from dispersed wastes of mechanical engineering

Abstract

The article describes the combined process of obtaining intermetallic alloys of the Fe-Al system from dispersed wastes of mechanical engineering. This process is based on a combination of electroslag casting with simultaneous self-propagating high-temperature synthesis. The formation of an intermetallic alloy occurs due to the use as a consumable electrode of a thin-walled steel tube filled with a charge consisting of a mixture of dispersed mechanical engineering waste (chip waste of steel, silumin, forge cinder, fluorspar), ground to a powdery state. Intermetallic compounds of the Fe-Al system have a unique high complex of physical-mechanical and service properties, they can effectively resist the corrosive effects of aggressive media and abrasive wear. These properties of the materials are of practical interest for a wide range of engineering industries. The materials based on iron aluminide Fe3Al should be especially noted. These materials have a low density (~6.7 g/cm3) in comparison with many high-temperature complex alloyed steels and alloys and at the same time their cost is significantly lower. The latter circumstance is due to the fact that in order to ensure a given level of service properties at high temperatures there is no need to use scarce alloying elements. However, there is a rather significant drawback of these materials. It is the brittleness of intermetallic phases, which hinders their widespread use. However, this drawback is leveled by technological methods of synthesizing the materials, leading to a decrease in grain size, elimination of water vapor in charge materials and the gas phase and alloying with chromium. The purpose of this study is to develop the technological foundations for obtaining intermetallic compounds of the Fe-Al system, which differ in the savings of energy and material resources with the recycling of dispersed wastes from mechanical engineering.