Study on the Natural Convection and Formation of Periodic Diphase Dendrite in Al-La Alloys

摘要：

In the crystal growth process, the temperature distribution and concentration distribution at the solid-liquid interface edge are always the hot problems. In this paper, we study the concentration distribution at the solid-liquid interface edge under the natural convection conditions, we find that the concentration field is oscillating exponential decline or rose along the crystal growth direction. We also study the dendrite morphology of Al-La alloys using the experimental method, the results show that the microstructure of Al-35％La alloys is different from the common microstructure of hypereutectic alloy during the conventional casting process, the first crystalline phase is All lLa3, which composition is discontinuous along the growth direction, the main dendrite is composed of α-Al alternating with All lLa3, the results of SEM and XRD show that the chemical composition along the main dendrite exhibits periodic behavior, therefore, this microstructure is named as periodic diphase dendrite structure.

关键词： Natural convection Al-La alloys periodic diphase dendrite

作者: Zheng Ya-hong Wang Yan-lin Wang Zi-dong

作者单位: School of Materials Science and Engineering,University of Science and Technology Beijing,Beijing 100083,China

会议类型: 国际会议

会议名称: 2010 International Conference on Material and Manufacturing Technology(2010材料与制造技术国际会议 ICMMT2010)

会议地点: 重庆

会议语种:英文

页码: 1308-1312

在线出版日期: 2010-09-17（万方平台首次上网日期，不代表论文的发表时间）