外加应力对Al-Cu及Al-Cu-Mg-Ag合金析出相生长的影响  

EFFECT OF EXTERNAL STRESS ON THE GROWTH OF PRECIPITATES IN Al-Cu AND Al-Cu-Mg-Ag ALLOYS

作　　者：陈大钦[1] 郑子樵[1] 李世晨[1] 陈志国[1] 刘祖耀[1] 

机构地区：[1]中南大学材料科学与工程学院,长沙410083

出　　处：《金属学报》2004年第8期799-804,共6页Acta Metallurgica Sinica

基　　金：国家自然科学基金资助项目 50271084

摘　　要：采用电阻法和透射电镜观察研究了应力对Al-3.88Cu(质量分数, ％,下同)和Al-3.87Cu-0.56Mg-0.56Ag合金时效析出相的影响,结果表明:外加应力促进原子团簇或GP区的形成但延缓θ‘和Ω相的析出与长大;Al-Cu-Mg-Ag合金时效动力学过程存在一个调整微观结构演化的临界应力值,在大于该值的应力作用下将有助于原子团簇或GP区的析出;Al-Cu合金和Al-Cu-Mg-Ag合金时效过程中引入外加应力导致沉淀相择优取向;采用Eshelby弹性夹杂物理论计算外加应力与错配应力场间的相互作用可分析产生应力位向效应的原因.The process of stress aging for Al-3.88Cu and Al-3.87Cu-0.56Mg-0.56Ag was investigated by electric resistivity measurement and transmission electron microscopy. The results indicate that external stress promotes the formation of clusters or GP zones, but retards the growth of theta' and Omega phases. A threshold stress which modifies the evolution of microstructure is found in Al-Cu-Mg-Ag alloy. The application of the external stress during aging induces preferred orientation of precipitates theta' and Omega in Al-Cu and Al-Cu-Mg-Ag alloys. The reason of stress oriented effect is analysed from the interaction between external stress and misfit strain by Eshelby elastic inclusion theory.

关 键 词：铝合金 应力时效 应力位向效应 错配应变 形核与生长 

分 类 号：TG111.5[金属学及工艺—物理冶金]