In the present study, AA2024-SiO_2np nanocomposites were prepared by the vortex method and effects of SiO₂ content on resulting microstructural and mechanical properties were investigated. The results indicate that the addition of 0.5vol% of nanoparticles decreased the size of the dendrite cell intervals by about 16%. The observed mechanical properties exhibited an improvement of about 17, 28, 10, 157, 8 and 13%, in hardness, ultimate tensile strength, yield strength, tensile elongation, flexural and shear strengths, respectively. With more considerable additions of nanoparticles, scanning electron microscopy investigations confirm that there were more significant amounts of nanoparticle agglomerates in the microstructure, which reduced the mechanical properties of 1vol% SiO_2np reinforced nanocomposite. The primary strengthening mechanisms evaluated appeared to be the effect of grain refinement (Hall–Petch), Orowan strengthening and the mismatch in coefficient of thermal expansion of the reinforcements and the matrix alloy. Evidence of some agglomerations of nanoparticles was recognized on the tensile fractured surfaces of the nanocomposites.

在本研究中，通过涡流法制备了AA2024-SiO _2np纳米复合材料，并研究了SiO ₂含量对所得显微组织和力学性能的影响。结果表明，添加0.5vol％的纳米颗粒将树枝状晶胞间隔的尺寸减小了约16％。观察到的机械性能分别在硬度，极限拉伸强度，屈服强度，拉伸伸长率，弯曲强度和剪切强度方面显示出约17、28、10、157、8和13％的改善。随着纳米粒子的大量添加，扫描电子显微镜研究证实，在微观结构中存在大量纳米粒子团聚体，这降低了1vol％SiO的机械性能。_2np增强纳米复合材料。评估的主要强化机制似乎是晶粒细化（Hall–Petch），Orowan强化以及强化物和基体合金的热膨胀系数不匹配的影响。在纳米复合材料的拉伸断裂表面上发现了一些纳米颗粒附聚的证据。