【摘要】 研究Al-Mg-Si合金在等温时效过程中的析出强化行为及其对力学性能的影响。利用原位同步辐射小角X射线散射(SAXS)技术和透射电子显微镜(TEM)对纳米析出相及其结构参数(尺寸、体积分数和数密度)进行表征。结果表明，棒状β’’析出相优先沿其纵向尺寸生长，但径向尺寸在时效5 h后达到峰值。如预测与测量的屈服强度和硬度结果所示，纳米析出相的尺寸和体积分数的增大与析出强化定量相关。SAXS为Ashby-Orowan模型提供了更可靠的输入参数，这有助于提高模型的预测精度和泛化能力。研究表明，随着时效时间的延长，Al-Mg-Si合金预测力学性能的演变与β’’析出相的平均半径和体积分数有关。更多还原

【Abstract】 The precipitation strengthening behavior and its effect on mechanical properties of Al-Mg-Si alloy during isothermal aging were investigated. In-situ synchrotron small angle X-ray scattering(SAXS) technique was used to characterize the nanoprecipitates and their structural parameters(size, volume fraction and number density) combined with transmission electron microscopy(TEM). The results show that rod-shaped β’’ precipitates grow preferentially along their longitudinal dimensions, but the radial dimension reaches a plateau after 5 h of aging. The growth of nanoprecipitates in size and volume fraction is quantitatively related to precipitation strengthening, as shown by predictions and measurements of relevant yield strength and hardness. SAXS provides more reliable input parameters for the Ashby-Orowan model, which improves the predictive accuracy and generalizability of the model. The study demonstrates that with increasing the aging time, the evolution of predictive mechanical properties of Al-Mg-Si alloy is dependent on the mean radius and volume fraction of β’’ precipitates.更多还原