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基于固体与分子经验电子理论,计算了Al-Cu-Mg-Ag合金中Ω、S与θ′相的价电子结构,用强化相最强共价键的共价电子对数nA分析并研究了Ω、S、θ′相与合金热稳定性的关系。结果表明,Ω、S与θ′相最强键共价电子对数nA分别为0.6591、0.5626、0.4917;Ω、S与θ′相最强键均远强于合金基体α-Al相的最强键,这是Al-Cu-Mg-Ag合金第二相强化的微观本质;Ω相耐热性高于θ′相与S相的原因在于Ω相原子所成共价键键强优于θ′与S相的共价键键强,这也是为获得具有良好高温性能的Al-Cu-Mg-Ag合金应尽量抑制θ′、S相形核,促进Ω相形核的原因。
Based on the empirical electron theory of solids and molecules, the valence electron structures of Ω, S and θ 'phases in Al-Cu-Mg-Ag alloys were calculated. The covalent electron pair nA of the strongest covalent bond in the strengthening phase was calculated and studied Relationship between Ω, S, θ 'Phase and Thermal Stability of Alloy. The results showed that the maximum nodal bonds of Ω, S and θ 'were 0.6591, 0.5626 and 0.4917, respectively. The strongest bonds of Ω, S and θ' were far stronger than that of the α-Al phase of the alloy matrix Bond, which is the microscopic nature of the second phase strengthening of the Al-Cu-Mg-Ag alloy. The reason why the heat resistance of the Ω phase is higher than that of the θ 'phase and the S phase is that the covalent bond formed by the Ω-phase atoms is superior to θ' And the S phase covalent bond is strong, which is why the Al-Cu-Mg-Ag alloy with good high-temperature performance should be inhibited as far as possible the θ ', S phase nucleation and promote the reason of Ω phase nucleation.