STRUCTURAL FEATURES AND MECHANICAL PROPERTIES OF RAPIDLY SOLIDIFIED AlSi ALLOYS

Nowadays, manufacturing of materials with unique properties is in the centre of attention of materials engineering. Aluminum and aluminum alloys are widely applied in variety of industries due to their high specific strength and in the following years they will become even more important. Construction elements made from aluminum and its alloys are produced mainly by casting or plastic working processes. In order to obtain the highest mechanical properties in afore mentioned materials their microstructure must be characterized by grain size on the level of sub- or nanoscale. This goal can be achieved on several ways including SPD methods or by applying more unconventional methods such as rapid solidification. In this paper mechanical properties and results of microstructure observations of AlSi5 and AlSi10 has been presented. Materials were obtained by two different methods. At first traditional casting followed by hot extrusion at the temperature of 400 degrees C was applied. The second manufacturing method was rapid solidification. In this case melted aluminum was casted on cold, fast rotating cooper wheel followed by plastic consolidation by hot extrusion. From obtained rods samples were cut for tensile test as well as microstructure observations which were performed both with a use of light and electron microscopy. Microstructure examination results and mechanical properties confirmed that rapid solidification significantly increases mechanical properties by structure refinement.