超声外场对7085铝合金基体组织及第二相的影响  

Effect of ultrasonic field on matrix structure and secondary phases of 7085 aluminum alloy

作　　者：黄明哲[1] 李晓谦[1] 蒋日鹏[1] 宁佳杰 

机构地区：[1]中南大学机电工程学院高性能复杂制造国家重点实验室,湖南长沙410083

出　　处：《中南大学学报（自然科学版）》2015年第7期2439-2445,共7页Journal of Central South University:Science and Technology

基　　金：国家重点基础研究发展规划(973计划)项目(2010CB731706;2012CB619504)~~

摘　　要：采用光学显微镜(OM)、扫描电镜(SEM)和电子探针(EPMA)等技术研究超声外场对7085铝合金基体组织以及第二相组织的影响规律。研究结果表明:与未施加超声外场的铸锭相比,经过超声外场处理的铸锭中呈现出大量尺寸细小、分布均匀的等轴晶组织,平均晶粒粒径减小到176μm,Zn和Mg在基体中的固溶度分别提高22%和54%;超声外场下,第二相组织的形貌和尺寸也得到很大的改善,失去长条状和针状的特征,呈现出细小弥散的第二相组织,θ+T共晶组织平均长度减少20%,Al3Fe相平均长度减少32%,Mg2Si相平均长度减少45%,Al3Fe相和Mg2Si相中的合金元素部分被固溶到基体组织中。Effects of ultrasonic on matrix structure and secondary phases were investigated by optical microscopy （OM）, scanning electron microscopy （SEM） and electron probe microanalysis （EPMA）. The results show that compared with the ingot casted without ultrasonic field, the ingot casted in the ultrasonic field presents large amounts of finer and more uniform equiaxed grains, the solidified structure of ultrasonic ingot is refined to 176 μn, and the matrix solubilities of Zn and Mg increase by 22% and 54%, respectively. In addition, the morphology and size of secondary phases are modified significantly in the ultrasonic field, which lose elongated and acicular characteristics, but a majority of fine and dispersive secondary phases are obtained. Besides, the average length of eutectic microstructure θ and T is decreased by 20%, the average length of A13Fe is decreased by 32%, the average length of Mg2Si is decreased by 45%, and some alloy elements of A13Fe and Mg2Si are dissolved into the matrix.

关 键 词：7085铝合金 超声 凝固 基体组织 第二相 

分 类 号：TG249.9[金属学及工艺—铸造] TB559[理学—物理]