基于固体与分子经验电子(Empirical electron theory of solids and molecules,EET)理论,计算了Ω相的价电子结构,分析了主键络的空间分布形态,研究了最强共价键与位错运动、共价电子密度与析出相强度、成键能力与析出相稳定性的关系。...基于固体与分子经验电子(Empirical electron theory of solids and molecules,EET)理论,计算了Ω相的价电子结构,分析了主键络的空间分布形态,研究了最强共价键与位错运动、共价电子密度与析出相强度、成键能力与析出相稳定性的关系。结果表明:Ω相共价主干键络呈三维“梅花”状分布,“花心”由Cu-Cu原子最强共价键连接;基体α最强共价键的键合力n1α为0.20857,Ω相的n1Ω为0.49056,基体{111}晶面上析出的Ω相使{111}晶面上位错滑移的阻力增加135.20%;从共价电子密度看,Ω相强度比S、θ′相的分别大2.67%和15.83%;从成键能力看,Ω相的稳定性比S和θ′相的分别大91.31%和291.92%;从共价电子结构看,{111}晶面析出的Ω相的沉淀硬化能力比{001}晶面析出的S、θ′相强。展开更多
The effect of trace elements Mg and Ag on the aging precipitation has been studied. It has been shown that both Mg and Ag have no obvious effect on the aging pre- cipitates but influence the nucleation and growth velo...The effect of trace elements Mg and Ag on the aging precipitation has been studied. It has been shown that both Mg and Ag have no obvious effect on the aging pre- cipitates but influence the nucleation and growth velocities of the precipitates in binary Al-Cu alloy if added separately. However, when Al-Cu alloy contains both elements Mg and Ag, Mg and Ag atoms strongly attract each other and form atom clusters along the matrix {111} planes. These atom clusters help the Cu atoms aggregate and nucleate het- erogeneously along the matrix {111} planes, which makes Mg atom clusters the optimized nucleation sites for Ω phase and inhibit the nucleation of θ′ phase.展开更多
基金funded by the National Key Research and Development Program of China(No.2021YFB3700801)by the State Key Laboratory of Powder Metallurgy,Central South University,Changsha,China。
文摘基于固体与分子经验电子(Empirical electron theory of solids and molecules,EET)理论,计算了Ω相的价电子结构,分析了主键络的空间分布形态,研究了最强共价键与位错运动、共价电子密度与析出相强度、成键能力与析出相稳定性的关系。结果表明:Ω相共价主干键络呈三维“梅花”状分布,“花心”由Cu-Cu原子最强共价键连接;基体α最强共价键的键合力n1α为0.20857,Ω相的n1Ω为0.49056,基体{111}晶面上析出的Ω相使{111}晶面上位错滑移的阻力增加135.20%;从共价电子密度看,Ω相强度比S、θ′相的分别大2.67%和15.83%;从成键能力看,Ω相的稳定性比S和θ′相的分别大91.31%和291.92%;从共价电子结构看,{111}晶面析出的Ω相的沉淀硬化能力比{001}晶面析出的S、θ′相强。
文摘The effect of trace elements Mg and Ag on the aging precipitation has been studied. It has been shown that both Mg and Ag have no obvious effect on the aging pre- cipitates but influence the nucleation and growth velocities of the precipitates in binary Al-Cu alloy if added separately. However, when Al-Cu alloy contains both elements Mg and Ag, Mg and Ag atoms strongly attract each other and form atom clusters along the matrix {111} planes. These atom clusters help the Cu atoms aggregate and nucleate het- erogeneously along the matrix {111} planes, which makes Mg atom clusters the optimized nucleation sites for Ω phase and inhibit the nucleation of θ′ phase.
