The locking of 〈110〉 edge dislocations on {001} in L12 ordered compounds: High-resolution electron-microscopy observations
The locking of 〈110〉 edge dislocations on {001} in L12 ordered compounds: High-resolution electron-microscopy observations
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DOI：
10.1080/01418619108221188
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发表时间：
1991-08
影响因子：
1.6
通讯作者：
Y. Sun;P. Hazzledine;M. Crimp;A. Couret
中科院分区：
文献类型：
--
作者：
Y. Sun;P. Hazzledine;M. Crimp;A. Couret
在L12有序合金的<$110 <${001}滑移系中，螺型位错和刃型位错都可以通过解离成非平面结构而被锁定。本文用弱束显微镜和点阵成像显微镜观察了Ni_3Ga和Ni_3（Al，Ti）单晶中[110]（001）立方系的刃位错结构。在600°C附近，刃型超位错被锁定在双Lomer-Cottrell锁中;在700°C附近，刃型位错被锁定在由攀爬解离形成的非平面结构中。这两种结构都可以通过高分辨电子显微镜直接观察到。讨论了刃型位错闭锁对<$110 <${001}和<$110 <${111}滑移系的影响。
Abstract In the 〈110〉{001} slip system in L12 ordered alloys, both screw and edge dislocations may become locked by dissociating into nonplanar structures. In this paper the structure of edge dislocations in the [110](001) primary cube system in Ni3Ga and Ni3(Al, Ti) single crystals has been observed with weak-beam and lattice-imaging microscopy. Near 600°C the edge superdislocations are locked in the double Lomer—Cottrell lock; near 700°C the edge dislocations are locked in nonplanar structures formed by climb dissociations. Both structures have been observed directly by high-resolution electron microscopy. The implications of the locking of the edge dislocations on the operation of 〈110〉{001} and 〈110〉{111} slip systems are discussed.