中文摘要：

将亚共晶Zn-A1合金凝固，借助EBSD技术研究了其组织的晶体学特征。结果表明，在样品上部形成了由多个伸长共晶团构成的羽毛状组织，且此共晶团中∥和口相存在取向关系{0001}II{111}〈19-10〉pII〈110〉n。其次，初生卢相沉积在样品下部，且其呈扁平枝晶状：六个一次枝晶臂沿〈lOiO〉方向快速生长而沿〈0001〉方向则生长缓慢。此外，初生卢相内部存在a相析出物，且初生卢与此口也存在上述取向关系，但初生卢与周围的伪初生口及其附近的共晶卢与口之间没有特定取向关系。

英文摘要：

A hypoeutectic Zn-4.45 mass%Al alloy was molten and then slowly solidified in an electri- cal furnace. The microstructure and the relevant crystallographic feature on longitudinal section of the so- lidified alloy ingot were characterized by means of SEM with EBSD technique. The results show that feath- er-like structure consisted of some elongated eutectic colonies is developed in the upper part of the spec- imen and a specific crystallographic orientation relationship （OR） （{0001} β｜｜{111}, 〈 1210 〉β｜｜ 〈 110 〉α ） exists between β and a in the eutectic colonies. Moreover, the primary βdendrites are segregated in the lower part of the specimen with a fiat morphology： six primary arms grow quickly along 〈 1010〉 but slowly along 〈0001〉. In addition, some a precipitates are present in the interior of primary β dendrites, and there exists certain OR between β and α as that mentioned above. However, no specific OR is found between the primary β dendrites and their attached pseudo-primary α phase as well as between the adjacent eutectic β and α.