微觀組織的影響
(中南大學(xué) 材料科學(xué)與工程學(xué)院，長(zhǎng)沙 410083)
摘 要: 采用顯微硬度測(cè)試、拉伸實(shí)驗(yàn)、X射線衍射分析和透射電鏡觀察，研究微量Ge對(duì)低Cu/Mg比Al-Cu-Mg合金的時(shí)效特性及微觀組織演變的影響。結(jié)果表明：在Al-1.5Cu-4.0Mg(質(zhì)量分?jǐn)?shù)，%)合金中添加少量Ge能加速合金的時(shí)效進(jìn)程、提高合金的時(shí)效硬化和強(qiáng)化效果，添加0.25%Ge(質(zhì)量分?jǐn)?shù))的合金時(shí)效強(qiáng)化效果優(yōu)于添加0.5%Ge合金的；微量Ge的添加能促進(jìn)Al-1.5Cu-4.0Mg合金中T相的均勻形核析出，并使之細(xì)小彌散分布；微量Ge能降低缺陷濃度，抑制S相非均勻形核，導(dǎo)致S相析出的體積分?jǐn)?shù)略微減低。
關(guān)鍵字: 鋁合金；時(shí)效特性；顯微組織；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
