CAST BAR OF AN ALUMINUM ALLOY FOR WROUGHT PRODUCTS, HAVING IMPROVED MECHANICAL PROPERTIES AND WORKABILITY, AS WELL AS PROCESS FOR PRODUCING THE SAME

摘要

A CAST BAR OF AN ALUMINUM ALLOY FOR WROUGHTPRODUCTS, HAVING IMPROVED MECHANICAL PROPERTIESAND WORKABILITY, AS WELL AS PROCESS FORPRODUCING THE SAMEABSTRACTIn AA standard 5000 series aluminum base alloysfor wrought products, the large-sized products havebeen usually produced using large billets which hadnon-uniform cast structure, and the small-sizedproducts have been usually produced by using extrudedbars which had a disadvantageous directional property.The continuously cast bar of aluminum base alloys forwrought product according to the present invention: isof homogeneous structure; is free of defects; exhibitsexcellent mechanical properties, and; can be subjected,as cast or after a heat, treatment, to a workingoperation such as forging. A critical value of thesecondary dendrite arm spacing (DAS) and a criticalvalue of the size of the grain diameter and secondphase particles, which critical values are substanti-ally lower than those in the conventional aluminumalloy ingot, are responsible for fine cast structurecapable of remarkably enhancing the workability andthe mechanical properties of the aluminum base alloyshaving the following compositions.AA 5000 series alloy: 2.0-6.0 Mg; 0.03-0.3% Cr,and; balance Al.