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Generally, the good combination of pre-deformation and aging can improve the mechanical strength of the Al-Cu-Li-Mg alloys. However, the effects of pre-deformation on competitive precipitation relationship and precipitation strengthening have not been clarified in detail in Al-Cu-Li-Mg alloys with high Mg. In the present study, the effects of pre-deformation level on the microstructure and mechanical properties of an Al-2.95Cu-1.55Li-0.57Mg-0.18Zr alloy have been investigated. It is found that the introduction of dislocation by 5% pre-deformation can facilitate the precipitation of new successive composite precipitates and T 1 precipitates along the sub-grain boundaries or dislocations and inhibit the precipitation of dispersive GPB zones which is the main precipitates of the alloys without pre-deformation. The introduction of 5% pre-deformation can enhance the mechanical properties considerably. When the pre-deformation level increases from 5 to 15%, the number density of the successive composite precipitates and T 1 precipitates increases, and the aspect ratio of T 1 precipitates decreases. The decrease in T 1 precipitate aspect ratio and the increment of the successive composite precipitates result in the reduction in precipitation strengthening. Therefore, the increase in pre-deformation level from 5 to 15% does not further improve the mechanical properties of the alloys, although the dislocation strengthening increases continuously.

The effects of homogenization treatment on the electrical conductivity, tensile strength and microstructure of Al-B electrician round rod were investigated by means of tensile test, optical microscopy(OM), scanning electron microscopy (SEM), energy dispersive spectroscopy(EDS). The results indicate that during homogenization the grain boundary of samples became thinner, microstructure was more compact and well-distributed. As-cast Al electrician round rod has favorable comprehensive properties under homogenization at 430 for 3 h, the electrical ℃ conductivity and tensile strength reach to 58.1%IACS and 100MPa, respectively. Compared to the sample without homogenization, the electrical conductivity increased by 2.1%IACS in the case of tensile strength was not reduced. After 83% rolling processing of specimen with better comprehensive performance, the electrical conductivity and tensile strength of samples reach to 55.24%IACS and 209MPa, respectively.

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