Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
1790531 | Journal of Crystal Growth | 2014 | 7 Pages |
Abstract
A skull-aided technique (SAT) for directional solidification (DS) of Nb-41Ni-40Ti alloy was developed to avoid the reaction between the alumina crucible and melt. By using SAT in alumina crucibles, DS experiments were performed in a Bridgman-type apparatus at a constant temperature gradient (G=20 K/mm) and growth rates ranging from 3 to 70 μm/s. Continuous and well-aligned Nb-TiNi eutectic microstructure and planar solid/liquid interface were observed at 3-5 μm/s. Higher growth rates resulted in the cellular/dendritic eutectic growth and even the appearance of primary phase. The volume fraction of well-aligned Nb rods (VwellâNb) in the eutectic microstructure decreased with increasing growth rate (v), given as VwellâNb=11.8+109exp(âv/13.93). No ceramic inclusions were found in DS ingot, which demonstrated that the SAT was very effective in avoiding the crucible-melt reaction for DS of Nb-41Ni-40Ti alloy.
Related Topics
Physical Sciences and Engineering
Physics and Astronomy
Condensed Matter Physics
Authors
Erhu Yan, Xinzhong Li, Dongmei Liu, Yanqing Su, Jingjie Guo, Hengzhi Fu,