微观组织的影响
(中南大学 材料科学与工程学院，长沙 410083)
摘 要: 采用显微硬度测试、拉伸实验、X射线衍射分析和透射电镜观察，研究微量Ge对低Cu/Mg比Al-Cu-Mg合金的时效特性及微观组织演变的影响。结果表明：在Al-1.5Cu-4.0Mg(质量分数，%)合金中添加少量Ge能加速合金的时效进程、提高合金的时效硬化和强化效果，添加0.25%Ge(质量分数)的合金时效强化效果优于添加0.5%Ge合金的；微量Ge的添加能促进Al-1.5Cu-4.0Mg合金中T相的均匀形核析出，并使之细小弥散分布；微量Ge能降低缺陷浓度，抑制S相非均匀形核，导致S相析出的体积分数略微减低。
关键字: 铝合金；时效特性；显微组织；Ge
microstructure of Al-1.5Cu-4.0Mg alloy
（School of Materials Science and Engineering, Central South University, Changsha 410083, China）
Abstract:The effects of trace Ge additions on the aging behavior and microstructure of Al-Cu-Mg alloy with low ratio of Cu to Mg were investigated by the microhardness test, tensile test, XRD and TEM. The results indicate that the trace addition of Ge can increase the aging rate and enhance the effect of aging hardening and strengthening. Compared with Al-1.5Cu-4.0Mg-0.5Ge (mass fraction, %) alloy, the addition of 0.25%Ge has more favorable effect on aging strengthening. The trace addition of Ge can promote the homogeneous nucleation and the dispersive distribution of T phase and reduce the density of defects and the heterogeneous nucleation of S phase, resulting in slight reduction of the volume fraction of S phase.
Key words: aluminum alloy; aging characteristics; microstructure; Ge
