高纯Al-Cu-Mg-Ag合金的时效析出行为  

Ageing precipitation behavior of high purity Al-Cu-Mg-Ag alloy

作　　者：张坤[1] 戴圣龙[1] 黄敏 杨守杰[1] 颜鸣皋[1] 

机构地区：[1]北京航空材料研究院,北京100095

出　　处：《中国有色金属学报》2007年第3期417-421,共5页The Chinese Journal of Nonferrous Metals

基　　金：国家重点基础研究发展计划资助项目(2005CB623705)

摘　　要：利用拉伸力学性能测试和透射电镜等研究了高纯Al-Cu-Mg-Ag合金在长时间时效过程中的时效析出行为。结果表明:实验用高纯Al-Cu-Mg-Ag合金板材具有较好的热稳定性和塑性,经185℃时效50h后合金的强度较峰值状态仅下降6%～7%,同时伸长率δ10保持在8%以上;Ω相是高纯Al-Cu-Mg-Ag合金的主要强化相,当合金处于峰值状态时,Ω相与基体之间会产生较大的错配应变,并在Ω相的细小片层处产生位错,为随后二次析出相θ′的析出提供有利的形核位置;延长时效时间将促进尺寸较大的Ω相和大部分θ′相(包括先析出相和二次析出相)向平衡相θ转变,但Ω→θ的转变远比θ′→θ的转变缓慢。By tensile test and transmission electron microscopy, the ageing precipitation behavior of an experimental high purity Al-Cu-Mg-Ag tyPe alloy was investigated during a long period of ageing time. The results show that the experimental alloy has good ductility and heat resistance. Ω phase is the key hardening precipitate. The strength of the ageing alloy underwent at 185 ℃ for 50 h is only decreased by 6% to 7% of the peak-aged alloy, and the elongation ratio of δ10 retains up to 8%. Under condition of peak-aged, high misfit strain exists near Ω/α interface and leads to dislocation at the fine laths of Ω phase, which actually serve as favorable heterogeneous nucleation sites for secondary-precipitated phase Ω. As ageing time prolongs, larger Ω phase and mostly metastable θ′ phase including primary and secondary precipitate transmit to equilibrium θ phase, but the transmission procedure of Ω→θ is much slower than that of θ′→θ.

关 键 词：Al-Cu-Mg-Agg合金 Ω相 先析出相 二次析出相 粗化 

分 类 号：TG146[一般工业技术—材料科学与工程]