The effects of pressure on structural,elastic and electronic properties of Mg_(x)La(x=1,2,3)compounds are investigated by using CASTEP program based on the density functional theory.The calculated equilibrium lattice ...The effects of pressure on structural,elastic and electronic properties of Mg_(x)La(x=1,2,3)compounds are investigated by using CASTEP program based on the density functional theory.The calculated equilibrium lattice parameters at zero pressure agree well with available experimental and theoretical values.The calculated DOS show that the structure of these compounds remains mechanically stable and structural phase transformation is not induced with increasing pressure from 0 to 30 GPa,and their structural stability increases with pressure.The ductility of MgLa can be improved by increasing pressure,which is the same as Mg_(2)La in 0-20 GPa,while brittle behavior turns into ductile behavior in 0-5 GPa for Mg_(3)La.The resistance to volume deformation of Mg_(x)La(x=1,2,3)compounds can be improved as the pressure increases.The shear deformation resistance and elastic stiffness of Mg_(3)La can be enhanced by rising pressure,but MgLa and Mg_(2)La increase first and then decrease when pressure is up to 25 GPa.In addition,the three compounds exhibit the elastic anisotropy with pressure.展开更多
利用扫描电镜(SEM)、X射线衍射(XRD)等检测分析稀土元素La对Mg-6%Al-5%Pb(AP65)镁合金(质量分数)显微组织的影响,并采用恒电流法、动电位极化扫描法和析氢法研究La含量对AP65镁合金的腐蚀电化学性能的影响。结果表明:加入La能够使AP65...利用扫描电镜(SEM)、X射线衍射(XRD)等检测分析稀土元素La对Mg-6%Al-5%Pb(AP65)镁合金(质量分数)显微组织的影响,并采用恒电流法、动电位极化扫描法和析氢法研究La含量对AP65镁合金的腐蚀电化学性能的影响。结果表明:加入La能够使AP65镁合金α-Mg组织得到细化,生成针状稀土相Mg80(Al,La)17和块状稀土相Mg17(Al,La)12;添加La提高了AP65镁合金的电化学活性、耐腐蚀性能和阳极效率,使AP65的平均电位负移;当La含量为2%(质量分数)时,平均电位最负为-1.73 V(vs SCE)。添加6%La使AP65镁合金的平均析氢速率从1.75 m L/(cm2·h)下降到0.02 m L/(cm2·h),并且使阳极效率从74.30%上升到82.31%。展开更多
基金Projects(2012BAE01B04)supported by the National Key and Technology R&D Program of ChinaProject(KZCX2-XB3-06)supported by Western Action Program,Chinese Academy of Sciences
基金National Science and Technology Support Program(2012BAE01B04)Qinghai Province Natural Science Foundation of China(2014-ZJ-934Q)Western Action Program,Chinese Academy of Sciences(KZCX2-XB3-06)
基金National Natural Science Foundation of China(Nos.U1610123,51674226,51574207,51574206)Science and Technology Major Project of Shanxi Province(No.MC2016-06)+3 种基金International Science and Technology Cooperation Project of Shanxi Province(No.2015081041)Research Project Supported by Shanxi Scholarship Council of China(No.2016-Key 2)Transformation of Scientific and Technological Achievements Special Guide Project of Shanxi Province(No.201604D131029)China Postdoctoral Scien ce Foundation(No.2017M611202)。
文摘The effects of pressure on structural,elastic and electronic properties of Mg_(x)La(x=1,2,3)compounds are investigated by using CASTEP program based on the density functional theory.The calculated equilibrium lattice parameters at zero pressure agree well with available experimental and theoretical values.The calculated DOS show that the structure of these compounds remains mechanically stable and structural phase transformation is not induced with increasing pressure from 0 to 30 GPa,and their structural stability increases with pressure.The ductility of MgLa can be improved by increasing pressure,which is the same as Mg_(2)La in 0-20 GPa,while brittle behavior turns into ductile behavior in 0-5 GPa for Mg_(3)La.The resistance to volume deformation of Mg_(x)La(x=1,2,3)compounds can be improved as the pressure increases.The shear deformation resistance and elastic stiffness of Mg_(3)La can be enhanced by rising pressure,but MgLa and Mg_(2)La increase first and then decrease when pressure is up to 25 GPa.In addition,the three compounds exhibit the elastic anisotropy with pressure.
文摘利用扫描电镜(SEM)、X射线衍射(XRD)等检测分析稀土元素La对Mg-6%Al-5%Pb(AP65)镁合金(质量分数)显微组织的影响,并采用恒电流法、动电位极化扫描法和析氢法研究La含量对AP65镁合金的腐蚀电化学性能的影响。结果表明:加入La能够使AP65镁合金α-Mg组织得到细化,生成针状稀土相Mg80(Al,La)17和块状稀土相Mg17(Al,La)12;添加La提高了AP65镁合金的电化学活性、耐腐蚀性能和阳极效率,使AP65的平均电位负移;当La含量为2%(质量分数)时,平均电位最负为-1.73 V(vs SCE)。添加6%La使AP65镁合金的平均析氢速率从1.75 m L/(cm2·h)下降到0.02 m L/(cm2·h),并且使阳极效率从74.30%上升到82.31%。
