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运用固体经验电子理论(EET),对掺微量Sc和Zr的Al-Mg合金的价电子结构进行计算.结果表明:在合金熔体凝固过程中,Zr,Sc与Al原子存在强烈的相互作用,首先生成初生的Al3Sc和Al3(ZrxSc1-x)粒子作为合金的非均质晶核,起细化晶粒作用;在合金凝固的过程中,由Zr,Sc与基体Al原子的强烈相互作用,易形成Al-Zr,Al-Sc,Al-Zr-Sc偏聚区.在后续的均匀化热处理过程中,容易从这些偏聚区析出细小的与基体共格的次生Al3Sc和Al3(ZrxSc1-x)粒子.由于这些析出的细小粒子与基体共格,并存在强的Al-Zr,Al-Sc共价键,提升了合金整体的共价键强度,阻碍位错的运动,使合金的硬度和强度都得到提高,合金的热稳定性更好.
The valence electron structures of Al-Mg alloys doped with trace amounts of Sc and Zr were calculated by solid empirical electronic theory (EET). The results show that Zr, Sc and Al atoms strongly interact during solidification of the alloy melt, First of all, primary Al3Sc and Al3 (ZrxSc1-x) particles are generated as the heterogeneous nuclei of the alloy to refine the grain effect. During the solidification of the alloy, Zr and Sc strongly interact with the Al atoms of the matrix Forming Al-Zr, Al-Sc, Al-Zr-Sc segregation zone in the subsequent homogenization heat treatment process, easy segregation from these segregation of small segregation with the matrix of secondary Al3Sc and Al3 (ZrxSc1-x ) Particles. As these precipitated fine particles and the matrix, and the presence of strong Al-Zr, Al-Sc covalent bond, enhance the overall covalent bond strength of the alloy, impede the movement of dislocation, the alloy hardness and The strength is improved, the thermal stability of the alloy is better.