Electromagnetic levitation apparatus for investigations of the phase selection in undercooled melts by energy-dispersive x-ray diffraction
Electromagnetic levitation apparatus for investigations of the phase selection in undercooled melts by energy-dispersive x-ray diffraction
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通过能量色散 X 射线衍射研究过冷熔体相选择的电磁悬浮装置
DOI：
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发表时间：
2000
期刊：
影响因子：
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通讯作者：
W. Petry
中科院分区：
文献类型：
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作者：
C. Notthoff;H. Franz;M. Hanfland;D. Herlach;D. Holland;W. Petry
过冷熔体的亚稳态可以提供亚稳相的形成途径，亚稳相的晶体结构与稳定相不同。这里使用电磁悬浮技术来过冷无容器的大块熔体。该技术与同步辐射的能量色散x射线衍射相结合，可以对过冷Ni-V合金的快速结晶进行原位研究。选择二元Ni-V合金作为模型体系，是因为它在中等浓度下表现出三种不同的晶相，即bcc、fcc和四方结构的金属间相的相竞争。衍射实验提供了从过冷熔体的非平衡状态形成的各种晶相的直接识别。研究了不同浓度Ni-V合金过冷温度对相选择的影响。
The metastable state of an undercooled melt can provide access to the formation of metastable phases whose crystallographic structures differ from their stable counterparts. The electromagnetic levitation technique is used here to undercool bulk melts without containers. This technique, combined with energy dispersive x-ray diffraction of synchrotron radiation, allows in situ study of the rapid crystallization of undercooled Ni–V alloys. The binary Ni–V alloy was chosen as a model system, because it shows phase competition of three different crystallographic phases, bcc, fcc, and an intermetallic phase of tetragonal structure at intermediate concentrations. The diffraction experiments provide for direct identification of the various crystalline phases formed from the nonequilibrium state of the undercooled melt. The phase selection is investigated as a function of undercooling temperature for Ni–V alloys of different concentrations.