由于7xxx铝合金在冷变形状态下的可加工性有限,通过大塑性变形和时效处理强化7xxx铝合金具有挑战性.本研究旨在全面探讨在施加大塑性变形的同时,辅之以两种不同的时效处理工艺:变形前人工时效或变形后自然时效,对7005铝合金的强化作用.采用X射线衍射和扫描电镜研究经上述工艺处理后合金的显微组织演变,并用维氏硬度测试评价合金的强化作用.结果表明,通过施加大塑性变形,辅以变形后自然时效,合金的强化效果最好,其屈服强度提高到400 MPa以上,比常规T6处理后合金的屈服强度提高约1/3.这种高强度主要是由于晶粒细化、位错密度的增加和自然时效过程中析出相体积分数的增加而产生的.结合应用模型推断,自然时效过程中析出相体积分数的增加对合金的强化起决定性作用.“,”Strengthening of aluminium alloys 7xxx through the imposition of severe plastic deformation supplemented by ageing treatments is a challenge due to the limited workability of these alloys in cold deformation regimes. This study aims to comprehensively investigate the strengthening of aluminium alloy 7005 through the imposition of severe plastic deformation supplemented by two different ageing treatments: pre-deformation artificial ageing or post- deformation natural ageing. For this purpose, microstructure evolutions of the alloy processed through mentioned procedures were studied using X-ray diffraction and scanning electron microscopy while the alloy strengthening was evaluated using Vickers hardness measurement. Results show that a superlative strengthening is obtained through the imposition of severe plastic deformation supplemented by post-deformation natural ageing. For instance, the yield strength of the alloy increases to more than 400 MPa, about one-third greater than the counterpart amount after the usual T6 treatment. This superlative strength mainly occurs due to refinement of grains, an increase of dislocation density and an increase of volume fraction of the precipitates that appeared during natural ageing. Considering the applied models, it is inferred that the increase of volume fraction of precipitates that appeared during natural ageing has a determinative role in the strengthening of the alloy.