Deformation and fracture behaviour of directionally solidified NiAl-Mo and NiAl-Mo(Re) eutectic composites
Deformation and fracture behaviour of directionally solidified NiAl-Mo and NiAl-Mo(Re) eutectic composites
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DOI：
10.1080/01418619808241921
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发表时间：
1998-09
影响因子：
1.6
通讯作者：
A. Misra;Z. Wu;M. Kush;R. Gibala
中科院分区：
文献类型：
--
作者：
A. Misra;Z. Wu;M. Kush;R. Gibala
本文研究了定向凝固NiAl-Mo和NiAl-Mo（Re）共晶合金的力学行为。研究了NiAl-9at.% Mo共晶合金的热稳定性至少比NiAl高两倍。没有确定单一的主要增韧机制。韧性的提高归因于NiAl的本征增韧，由于从界面产生的位错，裂纹捕获，裂纹偏转沿着界面和裂纹桥接的组合。Mo纤维是由NiAl基体中析出的Al和Ni固溶强化的，具有较低的延展性。广泛的界面脱粘，特别是当纤维是倾斜或平行于裂纹平面。根据两相的弹塑性特性分析了裂纹沿着界面的偏转。与Re合金化是有效的，在降低复合材料中的钼纤维的硬度，但也减少了纤维排列相对于。
Abstract The mechanical behaviour of directionally solidified NiAl-Mo and NiAl- Mo(Re) eutectic alloys has been examined. The fracture toughness of a NiAl- 9 at.% Mo eutectic alloy is a factor of at least two higher than that of monolithic NiAl. No single dominant toughening mechanism was identified. The toughness enhancement was attributed to a combination of intrinsic toughening of NiAl due to dislocations generated from the interfaces, crack trapping, crack deflection along interfaces and crack bridging. The Mo fibres were solid solution strengthened by Al and Ni partitioned from the NiAl matrix and had low ductility. Extensive interface debonding was noted, particularly when the fibres were either inclined or parallel to the crack plane. The deflection of the crack along the interfaces was analysed in terms of the elastic and plastic properties of the two phases. Alloying with Re was effective in reducing the hardness of Mo fibres in the composite, but also reduced the fibre alignment relative to that...