The Production of Material with Ultrafine Grain Structure in Al-Zn Alloy in the Process of Rapid Solidification

In the aluminium alloy family, Al-Zn materials with non-standard chemical composition containing Mg and Cu are a new group of alloys, mainly owing to their high strength prop erties. Proper choice of alloying elements, and of the method of molten metal treatment and casting enable further shaping of the propertie s. One of the modern methods to produce materials with submicron structure is a method of Rapid Solidification. The ribbon cast in a melt s pinning device is an intermediate product for furth er plastic working. Using the technique of Rapid Solidification it is not possible to directly produce a solid structural material of the required shape and length. Therefore, the ribbon ofan ultrafine grain or nanom etric structure must be subjected to the operations of fragmentation, compaction, consolidation and hot extrusion. In this article the authors focussed their attentio n on the technological aspect of the above mentione d process and described successive stages of the fabricationof anAlZn9Mg2.5Cu1.8 alloy of ultrafinegrain structure designated for further plastic working, which enables making extruded rods or elements shaped by the die forging technology. Studies described in the articl e were performed under variable parameters determined experimentally in the course of the alloy manufacturing process, including casti ngby RS and subsequent fragmentation .