Microstructure and Mechanical Properties of As-cast 5182 Aluminum alloy Modified with Al-RE and Al-5Ti-1B Master Alloys

¹ Baotou Aluminum Limited Company, Baotou 014046, China
² Schools of Materials Science and Engineering, Inner Mongolia University of Technology., Hohhot 010051, China

^a nmgshenli@163.com
^b zhaoxuepingguo@163.com
^c shizm@imut.edu.cn
^* Corresponding author: nmgshenli@163.com

Abstract

The modification effects of Al-RE (rare earth) and Al-5Ti-1B master alloys on the microstructure and mechanical properties of as-cast 5182 aluminum alloys were studied. Experimental results show that both of the modifications refine the α-Al grains and the Mg₂Si and (FeMn)Al₆ eutectics. The Mg₂Al₃ phases exist in the forms of thin flake (β′-Mg₂Al₃) and small granule (β-Mg₂Al₃) for the unmodified 5182 aluminum alloy. Modifications with 0.1 wt% Al-5Ti-1B and 0.2 wt% Al-RE yield longer flakes of β′-Mg₂Al₃ and small amounts of β-Mg₂Al₃ granules. The other contents of the modifiers reduce the longer flakes of β′-Mg2Al3 but facilitate formation of the particles and islands of β-Mg2Al3. The 0.2 wt% of Al-RE modification yields the finest microstructure and the largest ductility; the 0.2 wt% of Al-5Ti-1B modification has better microstructure and the highest tensile strength.