采用各种分析手段研究Y和Ce元素在镁中的存在形式和热力学行为,以及稀土元素对镁合金组织的影响。结果表明,镁合金的晶界处先形成Mg12Ce相,继而生成Mg24Y5相。镁合金经过固溶和时效处理后,在晶界和晶粒内分别析出Mg12Ce和Mg24Y5相;随时...采用各种分析手段研究Y和Ce元素在镁中的存在形式和热力学行为,以及稀土元素对镁合金组织的影响。结果表明,镁合金的晶界处先形成Mg12Ce相,继而生成Mg24Y5相。镁合金经过固溶和时效处理后,在晶界和晶粒内分别析出Mg12Ce和Mg24Y5相;随时效时间延长,晶粒内逐渐出现更稳定的呈点状分布的相,它由Mg24Y5、Mg2Y及Mg Y 3种化合物组成,晶界上也出现了由多种镁铈金属间化合物组成的相,镁合金硬度随时效时间先升高后降低再升高。展开更多
The effects of Ce, Y and Gd additions on the as-cast microstructure and mechanical properties of Mg-3Sn-2Sr alloy were investigated and compared by scanning electron microscopy, X-ray diffraction, differential scannin...The effects of Ce, Y and Gd additions on the as-cast microstructure and mechanical properties of Mg-3Sn-2Sr alloy were investigated and compared by scanning electron microscopy, X-ray diffraction, differential scanning calorimetry analysis, tensile and creep tests. The results indicate that the Mg-3Sn-2Sr ternary alloy is mainly composed ofα-Mg, primary and eutectic SrMgSn, and Mg2Sn phases. After the additions of 1.0%Ce, 1.0%Y and 1.0%Gd to the Mg-3Sn-2Sr alloy, the Mg12Ce, YMgSn, GdMgSn and/or Mg17Sr2 phases are formed, respectively. At the same time, the formation of the primary SrMgSn phase is suppressed and the coarse needle-like primary SrMgSn phase is modified and refined. In addition, the additions of 1.0% Ce, 1.0% Y and 1.0% Gd to the Mg-3Sn-2Sr alloy can simultaneously improve the tensile and creep properties of the alloy. Among the Ce-, Y-and Gd-containing alloys, the tensile properties of the Ce-containing alloy are relatively higher than those of the Y-and Gd-containing alloys.展开更多
With the aim to further improve the mechanical properties of Mg-A1-RE-based alloy, Mg-3.0Al-1.8Ce-0.3Y-0.2Mn alloy was prepared by high-pressure die-casting technique. The microstructure, thermal stability of intermet...With the aim to further improve the mechanical properties of Mg-A1-RE-based alloy, Mg-3.0Al-1.8Ce-0.3Y-0.2Mn alloy was prepared by high-pressure die-casting technique. The microstructure, thermal stability of intermetallic phases and mechanical properties were investigated. The results show that the alloy is composed of fine primary a-Mg dendrites and eutectic in the interdendritic regions. The intermetallic phases in eutectic are Aln（Ce,Y）3 and A12（Ce,Y） with the former being the dominant one. The thermal stability of Al11（ce,Y）3 is conditioned. It is basically stable at temperature up to 200℃ within 800 h, while most of the Al11（Ce,Y）3 intermetallics transform to A12（Ce,Y） at higher temperature of 450 ℃ for 800 h. The alloy exhibits remarkably improved strength both at room temperature and 200℃, which is mainly attributed to the reinforcement of dendrite boundaries with Alll（Ce,Y）3 intermetallics, small dendritic arm spacing effect as well as the solid solution strengthening with Y element.展开更多
文摘采用各种分析手段研究Y和Ce元素在镁中的存在形式和热力学行为,以及稀土元素对镁合金组织的影响。结果表明,镁合金的晶界处先形成Mg12Ce相,继而生成Mg24Y5相。镁合金经过固溶和时效处理后,在晶界和晶粒内分别析出Mg12Ce和Mg24Y5相;随时效时间延长,晶粒内逐渐出现更稳定的呈点状分布的相,它由Mg24Y5、Mg2Y及Mg Y 3种化合物组成,晶界上也出现了由多种镁铈金属间化合物组成的相,镁合金硬度随时效时间先升高后降低再升高。
基金Project(CSTC2013jcyjC60001)supported by the Chongqing Science and Technology Commission of ChinaProject(KJ120834)supported by the Chongqing Education Commission of ChinaProject(CQUT1205)supported by the Open Funds from Key Laboratory of Manufacture and Test Techniques for Automobile Parts,Ministry of Education,Chongqing University of Technology,China
文摘The effects of Ce, Y and Gd additions on the as-cast microstructure and mechanical properties of Mg-3Sn-2Sr alloy were investigated and compared by scanning electron microscopy, X-ray diffraction, differential scanning calorimetry analysis, tensile and creep tests. The results indicate that the Mg-3Sn-2Sr ternary alloy is mainly composed ofα-Mg, primary and eutectic SrMgSn, and Mg2Sn phases. After the additions of 1.0%Ce, 1.0%Y and 1.0%Gd to the Mg-3Sn-2Sr alloy, the Mg12Ce, YMgSn, GdMgSn and/or Mg17Sr2 phases are formed, respectively. At the same time, the formation of the primary SrMgSn phase is suppressed and the coarse needle-like primary SrMgSn phase is modified and refined. In addition, the additions of 1.0% Ce, 1.0% Y and 1.0% Gd to the Mg-3Sn-2Sr alloy can simultaneously improve the tensile and creep properties of the alloy. Among the Ce-, Y-and Gd-containing alloys, the tensile properties of the Ce-containing alloy are relatively higher than those of the Y-and Gd-containing alloys.
基金Project (HEUCFR1128) supported by the Fundamental Research Funds for the Central Universities,ChinaProject (2010AA4BE031)supported by the Key Project of Science and Technology of Harbin City,China+1 种基金Projects (20100471015,20100471046) supported by the China Postdoctoral Science FoundationProject (LBH-Z09217) supported by the Heilongjiang Postdoctorial Fund,China
文摘With the aim to further improve the mechanical properties of Mg-A1-RE-based alloy, Mg-3.0Al-1.8Ce-0.3Y-0.2Mn alloy was prepared by high-pressure die-casting technique. The microstructure, thermal stability of intermetallic phases and mechanical properties were investigated. The results show that the alloy is composed of fine primary a-Mg dendrites and eutectic in the interdendritic regions. The intermetallic phases in eutectic are Aln（Ce,Y）3 and A12（Ce,Y） with the former being the dominant one. The thermal stability of Al11（ce,Y）3 is conditioned. It is basically stable at temperature up to 200℃ within 800 h, while most of the Al11（Ce,Y）3 intermetallics transform to A12（Ce,Y） at higher temperature of 450 ℃ for 800 h. The alloy exhibits remarkably improved strength both at room temperature and 200℃, which is mainly attributed to the reinforcement of dendrite boundaries with Alll（Ce,Y）3 intermetallics, small dendritic arm spacing effect as well as the solid solution strengthening with Y element.
