Influence of chemical composition and impurities on microstructure and formation of intermetallic phases in selected aluminum alloys

Abstract

Al-Si-Mg alloys account for the biggest percentage of cast pieces in the world and the automotive industry is one of major consumers of these alloys. The properties of Al alloys are influenced by their chemical composition, technology of casting, methods of forming and heat treatment. Alloying with Sr, Ti, B etc. can improve the structure of casts, the presence of Fe, Mn leads to creation of intermetallic phases of Alx(Fe,Mn)ySiz types. The experimental part complements this contribution with metallography and SEM/EDX analyses of three different specimens of cast Al alloys with and without heat treatment. Also, metallography results are given for Al profiles subjected to different working conditions. The mechanical properties of the cast alloys are evaluated by microhardness. The usability of Al-Si alloys with different elements in the automotive industry is demonstrated in this work.