7×××铝合金退火过程中二次Al_3(Sc,Zr)粒子的析出行为

Precipitation behavior of Al_3(Sc,Zr) secondary particles in 7××× aluminum alloys during annealing

采用透射电子显微镜,研究含钪Al-Zn-Mg-Cu-Zr系铸态合金在退火过程中二次Al3(Sc,Zr)粒子的析出形貌、尺寸及分布。结果表明:含0.20%Sc的7系铝合金铸态试样在450℃退火2h后,α(Al)基体内析出呈豆瓣状的二次Al3(Sc,Zr)粒子;在450℃退火32h后,Al3(Sc,Zr)粒子尺寸为16～23nm;在450℃退火32h后的二次Al3(Sc,Zr)相与α(Al)基体完全共格。

The microstructures,sizes and distribution of Al3（Sc,Zr） secondary particles in Al-Zn-Mg-Cu-Zr alloy containing Zr during annealing were studied by transmission electron microscopy.The results show that the bean-like Al3（Sc,Zr） secondary particles precipitate from α（Al） matrix in Al-Zn-Mg-Cu-Zr as-cast alloy with 0.20%Sc after annealing at 450 ℃ for 2 h.The size of the Al3（Sc,Zr） secondary particles is 16-23 nm after annealing at 450 ℃ for 32 h.These particles are completely coherent with the α（Al） matrix.