【摘要】 采用第一原理赝势平面波法,计算了单独添加微量SC、ZR及复合添加SC、ZR后AL-MG体系的能量与电子结构。结果显示:与纯AL和AL-MG比较,AL-SC、AL-MG-SC、AL3-SC、AL-ZR、AL-MG-ZR、AL3-ZR、AL-SC-ZR、AL-MG-SC-ZR的负合金形成热与结合能增大,表明这些晶胞在AL-MG合金体系中易形成且结构稳定;对电子态密度进一步分析发现,与单独添加SC或ZR相比,复合添加SC、ZR时,晶体在费米能级附近的低能区有更多的成键电子;复合添加SC和ZR,合金体系结晶凝固时,有更多的晶粒提供非均匀形核作用的场所,因而晶粒细化的效果明显好于单独添加SC或ZR。更多还原

【Abstract】 Energy and electron structure of trace Sc,Zr,respectively,and mixed Sc,Zr adding into Al alloy based on the first-principle pseudopotential plane-wave method were investigated.The results show that the cohesive energies and generation heating of Al-Sc,Al-Mg-Sc,Al₃Sc,Al-Zr,Al-Mg-Zr,Al₃Zr,Al-Sc-Zr,Al-Mg-Sc-Zr are higher than those of pure Al and Al-Mg alloy,exhibiting the easy generation and structure stability of these crystal cells in Al-Mg system alloy.Through further analyzing the densities of states （DOS）of the crystal cell,it is found that there are more amounts of bonding electron numbers near the Feimi level of the alloy system with mixed Sc and Zr addition than those of ones with Sc or Zr addition,respectively.The refinement effects of mixed Sc and Zr addition are superior to those of Sc or Zr addition,respectively,which is contributed to more grain as the heterogeneous nucleation sites with mixed Sc and Zr addition during solidification process.更多还原