Microstructure and mechanical properties of an Mg-4.0Sm-1.0Ca alloy during thermomechanical treatment

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• 作者：Xiaoping LUO (罗小萍) ; Daqing FANG (房大庆) ; ^{fangdaqingtykd@163.com" class="auth_mail" title="E-mail the corresponding author} ; Qiushu LI (李秋书) ; Yuesheng CHAI (柴跃生)
• 关键词：Mg-Sm-Ca alloy ; thermomechanical treatment ; microstructure ; mechanical properties ; rare earths
• 刊名：Journal of Rare Earths
• 出版年：2016
• 出版时间：November 2016
• 年：2016
• 卷：34
• 期：11
• 页码：1134-1138
• 全文大小：2493 K

文摘

The microstructure and mechanical properties of an as-cast Mg-4.0Sm-1.0Ca alloy were investigated during thermomechanical treatments consisting of hot extrusion, rolling, and aging at 473 K. Mg₄₁Sm₅ phases containing Ca and needle-like Mg₂Ca phases formed in the Mg matrix, and the average grain size and elongation were 4.2 μm and 27%, respectively, after hot extrusion, which implied an increase in ductility. In addition, after the rolling, the grain size was further refined, and the tensile strength increased to 293 MPa. A new precipitate Mg₃Sm was found in the peak-aged Mg-4.0Sm-1.0Ca alloy and this alloy displayed the best mechanical properties, with a peak hardness of 83 HV and ultimate tensile strength of 313 MPa; these properties were attributed to grain refinement strengthening, solid solution strengthening, work hardening, and precipitation strengthening.