摘要
将亚共晶Zn-Al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b和a相存在取向关系{}0001β||{}111α,<?12ˉ10?>β||<?11ˉ0?>α。其次,初生b相沉积在样品下部,且其呈扁平枝晶状:六个一次枝晶臂沿<101ˉ0>方向快速生长而沿<0001>方向则生长缓慢。此外,初生b相内部存在a相析出物,且初生b与此a也存在上述取向关系,但初生b与周围的伪初生a及其附近的共晶b与a之间没有特定取向关系。
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.
出处
《材料研究学报》
EI
CAS
CSCD
北大核心
2014年第2期126-132,共7页
Chinese Journal of Materials Research
基金
国家自然科学基金51201029
中国博士后科研基金资助项目2012M520637~~
关键词
材料科学基础学科
凝固
微观组织
晶体学
电子背散射衍射
foundational discipline in materials science, solidification, microstructure, crystallogra- phy, EBSD
