摘要
以Al-4Zr中间合金为原料,通过熔炼得到不同冷却速率的合金试样。利用X射线衍射(XRD)和能谱分析(EDS)确定了初生Al_3Zr相的微观结构,通过扫描电镜(SEM)观察了初生Al_3Zr相的数量、尺寸和二维形貌,使用强碱腐蚀并通过SEM观察到了初生Al_3Zr相的三维形貌,进而研究分析了冷却速率对Al-4Zr合金中的初生Al_3Zr相的影响以及不同冷却速率下初生Al_3Zr相的生长机制。结果表明:随着冷却速率的加快,初生Al_3Zr相的二维形貌由粗大的板条状向细针状转变,数量增加,尺寸减小。由于Al_3Zr相的{001}面为光滑界面,生长速率缓慢,冷却速率低时呈粗大板条状的Al_3Zr粒子三维形貌为厚板状,生长机制为二维晶核生长;冷却速率快时呈细针状的Al_3Zr粒子的三维形貌为薄片流星镖状,生长机制为小平面枝晶生长。
Al-4%Zr alloy was melted and cooled at different rates to get the samples. To study the effect of cooling rates on morphology and growth mechanism of primary Al3Zr phase, X-ray diffraction(XRD) and energy dispersive spectroscopy(EDS) were used to characterize the microstructure of the samples. Scanning electron microscopy(SEM) was taken to observe number, size and morphology of the phase. The results showed that with the increase of the cooling rate, the two-dimensional morphology of the primary Al3Zr phase was transformed from coarse plate shape to fine needle shape, and its size decreased and amount increased. Because {001} plane of Al3Zr was smooth and its growth rate was low, the three-dimensional morphology of Al3Zr showed thick plate shape and the growth mechanism was two-dimensional at low cooling rate. However, when the cooling rate became high, the three-dimensional phase changed to thin throwing-star shape and the growth mechanism turned to faceted dendritic growth.
作者
易珂可
姜锋
徐翩
彭勇宜
Yi Keke;Jiang Feng;Xu Pian;Peng Yongyi(School of Materials Science and Engineering,Central South University,Changsha 410083,China;Light Alloy Research Institute,Central South University,Changsha 410083,China;Science and Technology on High Strength Structural Materials Laboratory,Changsha 410083,China;School of Physical Science and Electronics,Central South University,Changsha 410083,China)
出处
《稀有金属》
EI
CAS
CSCD
北大核心
2019年第2期213-218,共6页
Chinese Journal of Rare Metals
基金
湖南省自然科学基金项目(2017JJ2310)
中南大学贵重仪器设备开放共享基金项目(CSUZC201720)资助
