Experimental Investigation and CALPHAD Assessment of the Eutectic Trough in the System NiAl-Cr-Mo

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• 作者：Jian Peng ; Peter Franke ; Hans J. Seifert
• 关键词：CALPHAD ; eutectic trough ; NiAl ; Cr ; Mo system ; solidification
• 刊名：Journal of Phase Equilibria and Diffusion
• 出版年：2016
• 出版时间：October 2016
• 年：2016
• 卷：37
• 期：5
• 页码：592-600
• 全文大小：2,135 KB
• 刊物类别：Physics and Astronomy
• 刊物主题：Physics
  Crystallography
  Thermodynamics
  Materials Science
  Engineering Thermodynamics and Transport Phenomena
  Ceramics,Glass,Composites,Natural Materials
  Metallic Materials
  
• 出版者：Springer Boston
• ISSN：1863-7345
• 卷排序：37

文摘

NiAl-based alloys are promising candidates for high-temperature structural applications but their use is restricted by the limited mechanical properties. However, an improved performance can be achieved by strengthening the NiAl matrix with embedded fibers of refractory metals, such as Cr and Mo. Such composites can be manufactured in-situ by directional solidification of alloys with eutectic composition. For these processes the location of the eutectic trough in the NiAl-Cr-Mo system has to be known. The determination of the respective compositions was achieved by combining experimental investigations with computational thermodynamics. Thus, a series of melts in the NiAl-Cr-Mo system were prepared and their microstructures were investigated after solidification. The information on the primary phases was used to model the liquidus surface of the system NiAl-Cr-Mo using the CALPHAD approach. For this purpose, the thermodynamic datasets of the respective sub-systems from the literature have been combined into a quaternary database. The database will be used in the development of NiAl-based alloys for directional solidification. The dataset allows the calculation of the eutectic temperatures, the phase fractions and further thermodynamic properties along the eutectic trough. The present dataset will provide a reliable description for the NiAl-Cr-Mo system, but other regions of the Al-Cr-Mo-Ni system have an inferior representation.