Effect of faceting on twin grain boundary motion in zinc
Effect of faceting on twin grain boundary motion in zinc
复制标题
刻面对锌孪晶边界运动的影响
DOI：
10.1016/j.matlet.2009.09.024
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发表时间：
2010
影响因子：
3
通讯作者：
V. Sursaeva
中科院分区：
文献类型：
--
作者：
V. Sursaeva
本文研究了Zn [112 <$0]单晶中非相干孪晶界的小面化和迁移。本文研究了孪晶板尖端非相干孪晶界的稳态形状，并在473 ~ 692 K温度范围内用偏振光原位测量了非相干孪晶界的迁移速度。在623 K以下，非相干孪晶界代表与相干孪晶界成43°角形成的小面。在623 K以上，非共格孪晶界代表晶面，随着温度的升高，晶面的位置由初始的孪晶界变为与共格孪晶界成75°角。低于623 K的非相干孪晶，晶界移动在非常低的实验确定的激活焓19.3 kJ/mol的小面迁移。在623 K以上，实验确定的小面迁移的激活焓为154.4 kJ/mol，这高于Zn中晶界扩散的激活焓。这些结果清楚地表明，有一个很强的效果上的孪晶尖端的迁移速度的晶界形状。我们假设该系统中存在晶界结构相变：在623 K时，具有高重合位点阵的晶面转变为具有无序结构的低重合位点阵的晶面。
Faceting and migration of incoherent twin grain boundary in Zn [112̅0] flat single crystals has been investigated. The stationary shape of the slowly migrating incoherent twin grain boundary of the twin plate tip was studied and migration velocity was measured in situ in the range from 473K to 692K using polarized light. Below 623K the incoherent twin grain boundary represents the facet which forms at a 43° angle to the coherent twin grain boundary. Above 623K the incoherent twin grain boundary represents the facet, whose position changes from the initial to 75° to the coherent twin grain boundary as temperature increases. Below 623K the incoherent twin, grain boundary moves at very low experimentally determined activation enthalpy 19.3 kJ/mol of facet migration. Above 623K the experimentally determined activation enthalpy for the facet migration is 154.4 kJ/mol, which is higher than the activation enthalpy of grain boundary diffusion in Zn. These results clearly indicate that there is a strong effect of the grain boundary shape on the migration velocity of the twin tip. We suppose that there is a grain boundary structural phase transition in this system: facet with high coincidence site lattice transforms to facet with low coincidence site lattice with disordered structure at 623K.