Cu－Zn－Al合金贝氏体的亚单元及其激发形核、台阶生长

SUBUNITS AND THEIR SYMPATHETIC NUCLEATION-LEDGEWISE GROWTH OF BAINITE IN A Cu-Zn-Al ALLOY

利用透射电镜（ＴＥＭ）观察到Ｃｕ－ｚｎ－Ａｌ合金贝氏体的亚单元结构，其形状、大小及分布规律与扫描隧道显微分析（ＳＴＭ）的结果一致．亚单元上有台阶存在，表明它们是通过台阶机制生长的。亚单元是通过激发形核的，观察到三种类型的激发方式：面－面激发、边－边激发及边－面激发．Ｃｕ－Ｚｎ－Ａｌ合金的贝氏体相变为激发形核－台阶生长过程．

The subunit of bainite in a Cu-Zn-Al alloy has been observed by means of TEM. The shape, size and distribution of subunits under TEM are the same as those obtained by scanning tunneling microscope. The ledges on subunit were found to be grown up by ledgewise mechanism. The subunits are sympathetically nucleated. Three types of sympathetic nucleation were observed: face-to-face, edge-to-edge and edge-to-face.