预变形对Al-Cu-Li-(Mg-Ag)合金时效析出行为的影响OA北大核心CSTPCD

The effect of pre-deformation on the precipitation behavior of Al-Cu-Li and Al-Cu-Li-(Mg-Ag)alloys during artificial aging(RA)was studied by the Vickers hardness test,transmission electron microscopy(TEM)and differential scanning calorimetry(DSC).The results showed that the precipitation of the θ' phase was the main phase after peak-aging in Al-Cu-Li alloy.Moreover,the dislocation caused by pre-deformation was beneficial to the precipitation of θ' phase in Al-Cu-Li alloy after aging but had little effect on the T1 phase.For the Al-Cu-Li-(Mg-Ag)alloy,the precipitation of the T1 phase and θ' phase was promoted by pre-deformation during RA.After the addition of trace Mg and Ag solute elements,the precipitation phase of Al-Cu-Li-Mg-Ag alloy was mainly the T1 phases after peak-aging,with fewer θ' phases.The number density of the T1 phases and θ' phases increased after the pre-deformation aging of the Al-Cu-Li-(Mg-Ag)alloy,that is,the pre-deformation promoted the precipitation of the T1 phases and θ' phases simultaneously.Within the pre-deformation range of Ɛ = 0～3％,the number density of the T1 phases increased with the increment of pre-deformation,and their size was also becoming more uniform and smaller.Thus,the alloy could obtain more excellent mechanical properties.