Al-Zn-Mg-Cu合金时效过程的小角度x射线散射研究

通过同步辐射小角度x射线散射方法（SAXS），研究了三种Al_Zn_ Mg_Cu合金沉淀析出过程显微结构参数（析出相尺寸和体积分数），随时效温度和时效时间 的演化，同时分析了Zn含量对合金沉淀析出过程的影响.结果表明，三种合金（A，B，C） 在实验条件下析出相均属于纳米尺度，析出相的最大体积分数随Zn含量的增加而增加，最大体积分数分别为0.023—0.028，0.052—0.054和0.04.在一定时效温度下，体积分数随时效时间的变化规律，符合析出相的形核、核长大和粗化动力学过程.  关键词： 小角度x射线散射 Al_Zn_Mg_Cu合金 时效 析出相尺寸 析出相体积分数

Small angle x-ray scattering study of precipitation in Al-Zn-Mg-Cu alloys

The evolution of microstructural parameters (mean size and volume fracti on) of precipitates in three types of Al_Zn_Mg_Cu alloys during ageing has been studied by synchrotron_radiation small angle x_ray scattering (SAXS). The influe nce of Zn content on the precipitation has been analyzed. The results show that the precipitates are in nanometer scale for the three types alloys (A, B, C) . Th e maxima of the precipitate volume fractions forA, Band Cincrease wi th Zn content and are about 0.023—0.028, 0.052—0.054 and 0.04 respectively The evolution of volume fra ction at a certain temperature is consistent with the kinetic process of precipi tate nucleation, growth and Ostwald ripening.