Modification of LPSO Structure in Mg-Ni-Y Alloy with Strontium

Abstract:

Effects of Sr levels on microstructure of the LPSO structure-containing Mg_98.5-xNi_0.5Y_1.0Sr_x(x=0, 0.05, 0.10, 0.20 at.%) alloy were studied by SEM/EDS and XRD. Without Sr addition, the Mg_98.5Ni_0.5Y_1.0 alloy consists of α-Mg and LPSO structure and the block LPSO structure is distributed along the grain boundary. After adding 0.05 at.% Sr element into Mg_98.5Ni_0.5Y_1.0 alloy, the amount of dendrites decreased. With the increase of Sr content, the size of α-Mg grains decreases firstly and then increases. Meanwhile, the LPSO structure is refined. The addition of Sr element also results in the obvious increment of the amount of lamellar structure, which stretched from the grain boundary to the matrix. The excessive Sr in high Sr-content alloys participates in the form of Mg-Ni-Y-Sr compound, which is distributed in the vicinity of LPSO structure. In addition, the Sr can also promote the formation of Ni-rich and Y-rich phases.

• Periodical: Materials Science Forum (Volume 941)
• Pages: 869-874
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.941.869
• Online since: December 2018
• Authors: Xiong Yang, Shu Sen Wu, Shu Lin Lü*, Liang Yan Hao, Xiao Gang Fang
• Keywords: Lamellar Structure, LPSO Structure, Mg-Ni-Y-Sr Alloy, Sr Modification

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