Effect of processing and Microalloying Elements on the Thermal Stability of Cr-Cr 3 Si and NiAl-Mo eutectic alloys
Effect of processing and Microalloying Elements on the Thermal Stability of Cr-Cr 3 Si and NiAl-Mo eutectic alloys
复制标题
加工和微合金元素对Cr-Cr 3 Si和NiAl-Mo共晶合金热稳定性的影响
DOI：
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发表时间：
2006
期刊：
影响因子：
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通讯作者：
E. George
中科院分区：
文献类型：
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作者：
A. Gali;H. Bei;E. George
通过研究具有片层结构的Cr-Cr{sub 3}Si和具有纤维结构的NiAl-Mo两种模型共晶体系，研究了多相金属间化合物在1400℃的热稳定性。在滴铸Cr-Cr{sub 3}Si中，粗化受界面控制。采用Ce和Re进行微合金化可以降低粗化速率，选择Ce和Re这两种元素是因为它们有望偏析到Cr-Cr{sub 3}Si界面并降低其能量。同样，定向凝固也能显著降低Cr-Cr{sub 3}Si的界面能，从而显著降低粗化速率。在NiAl-Mo的情况下，发现粗化是通过断层迁移和湮灭发生的。B微合金化可显著降低粗化率。掺B合金的纤维密度小于未掺B合金，说明B通过降低故障密度影响粗化速率。
The thermal stability of multiphase intermetallics at temperatures to 1400 C was investigated by studying two model eutectic systems: Cr-Cr{sub 3}Si having a lamellar microstructure and NiAl-Mo having a fibrous microstructure. In drop cast Cr-Cr{sub 3}Si, coarsening was found to be interface controlled. The coarsening rate could be reduced by microalloying with Ce and Re, two elements which were chosen because they were expected to segregate to the Cr-Cr{sub 3}Si interfaces and decrease their energies. Similarly, directional solidification, which is also expected to lower the Cr-Cr{sub 3}Si interfacial energy, was found to dramatically decrease the coarsening rate. In the case of NiAl-Mo, coarsening was found to occur by fault migration and annihilation. Microalloying with B was found to significantly decrease the coarsening rate. The fiber density in the B-doped alloy was smaller than in the undoped alloy, suggesting that B affects the coarsening rate by lowering the fault density.