Tilt $\{112\}$ grain boundaries (GBs) in bcc metals perform shear-coupled grain boundary migration by the creation and glide of disconnections. Disconnection dipoles may be created at the pristine GB at high stresses or may be generated at the core of a GB dislocation that acts as a source of disconnections. We characterize this source in terms of its Burgers vector, denoted ${\vec{b}}_{1/-1}$, and describe the mechanism that allows the source to move conservatively with the GB. The ${\vec{b}}_{1/-1}$ grain boundary dislocation is created, for instance, during the absorption of a crystal dislocation by the $\{112\}$ grain boundary. In addition, ${\vec{b}}_{1/-1}$ accommodates $\{112\}$ vicinal grain boundaries that are formed by segments of $\{112\}$ planes separated by ${\vec{b}}_{1/-1}$ grain boundary dislocations. The presence of these ${\vec{b}}_{1/-1}$ dislocations facilitates the conservative displacement of both, the pristine and the vicinal GBs. We show that the creation of disconnections is the key for the absorption of edge and screw dislocations by the GB and the transmission of mixed dislocations through the GB. These conservative processes are efficient ways to accommodate plastic deformation at the $\{112\}$ GB and its vicinal GBs. The same mechanism operates on the $\{112\}$ twin boundaries.

中文翻译：

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bcc-Fe中{112}孪晶中剪切耦合迁移和邻近晶界的原子过程

倾斜 $\{112\}$bcc金属中的晶界（GBs）通过产生和滑移断开来执行剪切耦合的晶界迁移。断开偶极子可能会在高应力下在原始GB处产生，也可能在GB错位的核心处产生，该位错是断开的来源。我们用汉堡矢量来表征此来源，表示为${\vec{b}}_{\mathrm{1个}/-\mathrm{1个}}$，并说明允许源随GB保守移动的机制。的${\vec{b}}_{\mathrm{1个}/-\mathrm{1个}}$ 晶界位错是在例如晶体吸收位错的过程中产生的。 $\{112\}$晶界。此外，${\vec{b}}_{\mathrm{1个}/-\mathrm{1个}}$ 容纳 $\{112\}$ 由以下部分形成的邻近晶界 $\{112\}$ 飞机由 ${\vec{b}}_{\mathrm{1个}/-\mathrm{1个}}$晶界位错。这些的存在${\vec{b}}_{\mathrm{1个}/-\mathrm{1个}}$脱位有利于原始GBs和邻近GBs的保守移位。我们表明，断开的产生是通过GB吸收边缘和螺钉位错以及通过GB传输混合位错的关键。这些保守的过程是适应塑性变形的有效方法。$\{112\}$GB及其附近的GB。相同的机制适用于$\{112\}$ 双重边界。