Compact seaweed growth of peritectic phase on confined, flat properitectic dendrites
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- 作者：A. Ludwig ludwig@unileoben.ac.at ; J. Mogeritsch
- 关键词：Peritectic solidification ; Dendritic-cellular transition ; Seaweed growth
- 刊名：Journal of Crystal Growth
- 出版年：2016
- 出版时间：1 December 2016
- 年：2016
- 卷：455
- 期：Complete
- 页码：99-104
- 全文大小：1561 K
- 卷排序：455
文摘
Peritectic alloys form a variety of different solidification morphologies at low growth rates. An alloy with a concentration that corresponds to the hyper-peritectic limit should show a cellular/dendritic solidification of the peritectic phase for growth velocities above the corresponding constitutional undercooling limit. However, due to nucleation retardation of the peritectic phase we observed growth of properitectic dendrites before cellular growth of the peritectic could established. The transition happened via an overgrowth of dendrites with a thin layer of peritectic phase. The observations were made using a transparent, metal-like solidifying peritectic system that was solidified directionally in thin samples. In the gap between the flat dendrites and the tubing walls, the peritectic phase grew with a compact seaweed morphology, whereas in the interdendritic spacing it formed small-curved bumps. At same distance behind the tip region, more and more polycrystalline-like objects appeared at the elongated traces of the compact seaweed morphology.