Application of the Peierls–Nabarro Model to Symmetric Tilt Low-Angle Grain Boundary with Full Dislocation in Pure Magnesium
来源期刊：Acta Metallurgica Sinica2016年第11期
论文作者：Tou-Wen Fan Xiu-Bo Yang Jiang-Hua Chen Ling-Hong Liu Ding-Wan Yuan Yong Zhang Cui-Lan Wu
文章页码：1053 - 1063
摘 要：Three types of symmetric（110） tilt low-angle grain boundaries（LAGBs） with array of basal, prismatic, and pyramidal edge full \a[ dislocations in pure Mg have been studied by using the improved Peierls–Nabarro model in combination with the generalized stacking fault energy curve. The results show that with decreasing distance between the dislocations in all the three types of tilt LAGBs, the stress and strain fields are gradually suppressed. The reduction extent of the stress and strain fields decreases from the prismatic to basal to pyramidal dislocations. The variation of dislocation line energy（DLE） for all tilt LAGBs is divided into three stages: DLE changes slightly and linearly when the distance is larger than 300 , 10%; DLE declines exponentially and quickly when the distance goes from 300 to 100 , 70%; and finally, the descent speed lowers when the distance is smaller than 100 and the dislocation core energy is nearly half of the DLE. The grain boundary energy（GBE） decreases when the tilt angle of LAGB increases from 1° to 2° for all cases.The tilt LAGB consists of pyramidal dislocations always has the largest GBE, while that with array of prismatic dislocations has the smallest one in the whole range. The Peierls stress of dislocation in tilt LAGB is nearly unchanged, the same as that of single dislocation. This work is useful for further study of dissociated dislocation, solute segregation, precipitate nucleation in tilt LAGB and its interaction with single dislocations.
Tou-Wen Fan1，Xiu-Bo Yang1,2，Jiang-Hua Chen1,3，Ling-Hong Liu1,4，Ding-Wan Yuan1，Yong Zhang1，Cui-Lan Wu1
1. Center for High-Resolution Electron Microscopy, College of Materials Science and Engineering, Hunan University2. Department of Applied Physics, School of Physics and Electronics, Hunan University3. Hunan Province Key Laboratory for Spray Deposition Technology and Application, Hunan University4. College of Science, Central South University of Forestry and Technology
摘 要：Three types of symmetric（110） tilt low-angle grain boundaries（LAGBs） with array of basal, prismatic, and pyramidal edge full \a[ dislocations in pure Mg have been studied by using the improved Peierls–Nabarro model in combination with the generalized stacking fault energy curve. The results show that with decreasing distance between the dislocations in all the three types of tilt LAGBs, the stress and strain fields are gradually suppressed. The reduction extent of the stress and strain fields decreases from the prismatic to basal to pyramidal dislocations. The variation of dislocation line energy（DLE） for all tilt LAGBs is divided into three stages: DLE changes slightly and linearly when the distance is larger than 300 , 10%; DLE declines exponentially and quickly when the distance goes from 300 to 100 , 70%; and finally, the descent speed lowers when the distance is smaller than 100 and the dislocation core energy is nearly half of the DLE. The grain boundary energy（GBE） decreases when the tilt angle of LAGB increases from 1° to 2° for all cases.The tilt LAGB consists of pyramidal dislocations always has the largest GBE, while that with array of prismatic dislocations has the smallest one in the whole range. The Peierls stress of dislocation in tilt LAGB is nearly unchanged, the same as that of single dislocation. This work is useful for further study of dissociated dislocation, solute segregation, precipitate nucleation in tilt LAGB and its interaction with single dislocations.
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