Mechanical and electrochemical behavior of Mg-Al-Si alloys fabricated with formation of fine Mg2Si phase

Abstract

In the present work, Mg-Si-Al alloys were synthesized with the addition of silicon (1, 4, and 6 wt. %) and aluminum (6 wt.%) in magnesium. The objective of this study was the formation of fine Mg2Si phase via powder metallurgy process using high energy ball milling and to investigate the microstructural, mechanical, and corrosion behavior of different composition of alloys. With increasing wt. % of Si, average grain size of Mg2Si phase decreased and compressive fracture strain increased. According to fractographic patterns, it was revealed that AS61 alloy specimens fractured along the grain boundaries. However pure Mg, AS64 & AS66 specimens show shear plane fracture via twinning. The compressive yield strength of pure Mg and AS64 alloy were significantly affected by the twinning. The compressive yield strength of pure Mg and AS64 alloy were lower than AS61 alloy. To understand electrochemical, mechanical and structural integrity of the prepared alloys, tests for corrosion in 0.6 M NaCl solution, bulk density, porosity, and Vickers hardness were also performed.