Transactions of Nonferrous Metals Society of China
JOURNAL OF RAILWAY SCIENCE AND ENGINEERING
|Vol. 9 No. 4 December 1999|
（Department of Materials Science and Engineering,Tsinghua University, Beijing 100084, P. R. China）
Abstract:The crystal heterogeneous nuclei of high purity aluminum refined by Al-Ti-B master alloy were studied by SEM and the mechanism of heterogeneous nucleation was discussed. It was found that the cluster of TiB2 particles was in the center of grains, and a number of small protrusions were found on the surface of the particles. It was also found that the cluster was surrounded with the dendrites or circles enriched in Ti.
Key words: aluminum; heterogeneous nucleation; refining mechanism