摘要
利用扫描电镜、金相显微镜和EDS能谱分析研究了含Mn弥散颗粒在Al-Mg-Si-Mn铝合金均匀化过程中的析出分布。结果表明:铸锭中显微偏析严重的Si在Al基体中的扩散对弥散颗粒的析出分布有重要的影响。合金在均匀化过程中析出杆状AlMnSi和块状Al(MnFe)Si两种含Mn弥散颗粒。这些颗粒首先在晶界附近的Si元素过饱和固溶区中析出,随保温时间延长颗粒分布逐渐均匀;同时利用Fick第二定律导出了描述均匀化程度的残余显微偏析指数公式,公式指出提高均匀化温度,减小枝晶间距可加快均匀化进程。
The distribution of dispersion particles containing Mn in Al-Mg-Si-Mn alloy during homogenization was studied by SEM, EDS. The results show that rod-like AlMnSi particles and blocky Al（MnFe）Si particles precipitate in the alloy during homogenization. The diffusion of Si through Al-matrix is very important to the uniformity of particles distribution. Precipitation takes place firstly in the Si supersaturated regions which are perimetric to the dendrite arms. With the increase of holding time, the dispersoid distribution becomes more and more uniform. In order to determine the degree of homogenization, the index of residual micro-segregation equation was deduced by Fick＇s second law. The equation indicates that the increase of temperature and the decrease of dendrite arm spacing will accelerate the homogenization process.
出处
《热加工工艺》
CSCD
北大核心
2008年第18期21-24,共4页
Hot Working Technology
