The effect of Ce/La misch metal addition on the microstructural evolution of as-cast and as-soluted Mg-5.3Zn-0.5Ca(wt.%) alloys was systematically investigated. It was found that Ce/La could effectively refine the as-...The effect of Ce/La misch metal addition on the microstructural evolution of as-cast and as-soluted Mg-5.3Zn-0.5Ca(wt.%) alloys was systematically investigated. It was found that Ce/La could effectively refine the as-cast alloy and restrain grain growth during solution treatment, which was derived from the constitutional supercooling during solidification process and the formation of stable intermetallic compounds Ce Mg12 and Mg17La2. Furthermore, Ce/La microalloying and solution treatment resulted in an evolution from the original lamellar Ca2Mg6Zn3/α-Mg to the divorced eutectic structure. The thermal stability of Mg-Zn-Ca alloy could be effectively improved by Ce/La addition, because the low-melting-point binary Mg-Zn phase was transformed to Mg x Zn y-Ca-(Ce/La) phase with higher thermal stability and the amount of Ca2Mg6Zn3/α-Mg eutectic structure was reduced.展开更多
An environment-friendly cerium-based sealing treatment was developed to improve the surface integrity and corrosion resistance of Mg–Al hydrotalcite film on AZ91D magnesium alloy. The cerium dioxide was generated thr...An environment-friendly cerium-based sealing treatment was developed to improve the surface integrity and corrosion resistance of Mg–Al hydrotalcite film on AZ91D magnesium alloy. The cerium dioxide was generated through three stages namely nucleation, growth and dissolution, modifying the surface of AZ91D Mg alloy, and the hydrotalcite film became integral after being treated for 30 min. The results of polarization curves showed that the anti-corrosive performance of the hydrotalcite film was enhanced by the sealing treatment. Moreover, the immersion tests and electrochemical impedance spectrum measurements also demonstrated that the sealed hydrotalcite film provided a longer-term protection of magnesium alloy from corrosion as compared to the unsealed one.展开更多
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
基金Project (51001034) supported by the National Natural Science Foundation of ChinaProjects (2008AA4CH044, 2009AA1AG065,2010AA4BE031) supported by the Key Project of Science and Technology of Harbin City, China+2 种基金Project (HEUCF201210004) supported by the Fundamental Research Funds for the Central Universities,ChinaProject (20092304120020) supported by the Research Fund for the Doctoral Program of Higher Education,ChinaProject (11553054) supported by the Project of Science and Technology of Heilongjiang Province Education Department,China
基金supported by the National Natural Science Foundation of China(51401200)Natural Science Foundation of Jilin Province(20140520099JH)+4 种基金National Science & Technology Pillar Program(2012BAE01B04)Chinese Academy of Sciences of Western Action Plan Project(KZCX2-XB3-06)the National Natural Science Foundation of China Major Project(91122030)National High Technology Research and Development Program of China(2011AA03A407)National Natural Science Foundation for Creative Research Group(20921002)
文摘The effect of Ce/La misch metal addition on the microstructural evolution of as-cast and as-soluted Mg-5.3Zn-0.5Ca(wt.%) alloys was systematically investigated. It was found that Ce/La could effectively refine the as-cast alloy and restrain grain growth during solution treatment, which was derived from the constitutional supercooling during solidification process and the formation of stable intermetallic compounds Ce Mg12 and Mg17La2. Furthermore, Ce/La microalloying and solution treatment resulted in an evolution from the original lamellar Ca2Mg6Zn3/α-Mg to the divorced eutectic structure. The thermal stability of Mg-Zn-Ca alloy could be effectively improved by Ce/La addition, because the low-melting-point binary Mg-Zn phase was transformed to Mg x Zn y-Ca-(Ce/La) phase with higher thermal stability and the amount of Ca2Mg6Zn3/α-Mg eutectic structure was reduced.
基金supported by the Jiangsu Key Laboratory of Advanced Structural Materials and Application Technology (No. ASMA201407)the Innovative Foundation Project for Students of Jiangsu Province (No. 201511276012Z)the Innovative Foundation Project for Students of Nanjing Institute of Technology (No. TB201617004)
文摘An environment-friendly cerium-based sealing treatment was developed to improve the surface integrity and corrosion resistance of Mg–Al hydrotalcite film on AZ91D magnesium alloy. The cerium dioxide was generated through three stages namely nucleation, growth and dissolution, modifying the surface of AZ91D Mg alloy, and the hydrotalcite film became integral after being treated for 30 min. The results of polarization curves showed that the anti-corrosive performance of the hydrotalcite film was enhanced by the sealing treatment. Moreover, the immersion tests and electrochemical impedance spectrum measurements also demonstrated that the sealed hydrotalcite film provided a longer-term protection of magnesium alloy from corrosion as compared to the unsealed one.
基金The National Natural Science Foundation of China(51361010)Natural Science Foundation of Jiangxi province(20114BAB216015)+1 种基金ScientificResearch Fund of Jiangxi Provincial Education Department(GJJ12320)The State Key Laboratory of Solidification Processing in NWPU(SKLSP201321)
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。
