Microstructure of the Hypoeutectic Al-Mg Alloy Solidified at 4 GPa High Pressure

Zhen-Ling Wang¹, Yu-Cheng Yu¹, Zun-Jie Wei²ª¤

(1.College of Materials Science and Engineering, Heilongjiang University of Science and Technology, Harbin 150022, China;ª¤ 2.School of Materials Science and Engineering, Harbin Institute of Technology, Harbin 150001, China)ª¤ª¤ª¤



Abstract:

High pressure solidification rules of Al-Mg alloy needs to be discussed further for its wide range of application. Microstructures and phases of Al-25wt£¥Mg alloy solidified at 4 GPa were studied by optical microscope, X-ray diffractmeter, energy dispersive X-ray spectroscopy and transmission electron microscopy (TEM). The microstructure evolution mechanism of Al-25Mg alloy under high pressure was analyzed. The result shows that the alloy consists of ¦Á-Al phase and Al₃Mg₂ phase under normal pressure. However, only Al₁₂Mg₁₇ phase forms without Al₃Mg₂ phase at 4 GPa. In addition, Mg concentration in ¦Á-Al phase increases and that of the lattice constant also increases. The ¦Á-Al dendrite presents the broken arms under normal pressure, after high pressure solidification, the morphology of the dendrite tends to integrate and the size of the dendrite arms decreases.ª¤

Key words:  Al-25Mg alloys  High pressure solidification  microstructure  phaseª¤

DOI£º10.11916/j.issn.1005-9113.2013.05.018

Clc Number:TG146.2+1

Fund: