Influence of Y and La Additions on Grain Growth and the Grain-Boundary Character Distribution of Alumina

2013 ◽  
Vol 97 (2) ◽  
pp. 622-630 ◽  
Author(s):  
Stephanie A. Bojarski ◽  
Michael Stuer ◽  
Zhe Zhao ◽  
Paul Bowen ◽  
Gregory S. Rohrer
2018 ◽  
Vol 917 ◽  
pp. 223-227
Author(s):  
Suok Min Na ◽  
Nicholas J. Jones ◽  
Alison B. Flatau

Grain growth and grain boundary character distribution relationships in Fe-Ga rolled sheet is investigated to study the influence of H2S gas content in argon on the development of selective grain growth through secondary recrystallization. Abnormal growth of (011) grains was predominant at the low content of H2S gas, while (113) grain growth was well developed at contents higher than 1.33% H2S. On the other hand, the development of (001) grains was challenging to produce because it is very sensitive to the anneal environment and has a relatively low fraction of high energy grain boundaries associated with misorientation angles that determine the mobility of boundaries.


Author(s):  
Khaled J. Al-Fadhalah

The effect of texture on grain boundary character distribution (GBCD) in thermomechanically processed oxygen-free high-conductivity copper has been investigated. Copper samples were cold rolled to a reduction in thickness of 50% and then annealed for 60 min in the range of 400–600°C. GBCD and texture were measured using electron backscatter diffraction. The fraction of special boundaries (Σ3, Σ9, and Σ27) varied from 59% to 71%, with the maximum in the sample annealed at 500°C. The results indicate that cold rolling provided a strong texture of brass type. It was found that the sample annealed at 500°C have texture components of cube, Goss, rotated-Goss, and Y orientations. These texture components were in relation with the formation of annealing twins and Σ3 boundaries. It was also shown that twin-induced GBCD evolution occurred by strain-induced boundary migration, multiple twinning, and conventional recrystallization. Annealing at 600°C caused full recrystallization and grain growth, showing a strong cube recrystallization texture. The grain growth was found to hinder the formation of special boundaries.


Author(s):  
Ming Huang ◽  
Kunpeng Zhao ◽  
Ziyun Chen ◽  
Yuan Qin ◽  
Xinye Yang ◽  
...  

Abstract Although thermomechanical processing has been widely used in grain boundary engineering, the relationship between thermomechanical parameters and grain boundary character distribution is still not well understood. In the present study, electron backscatter diffraction was used to study the grain boundary character distribution in pure copper after lowstrain thermomechanical treatments. It was found that the low-R coincidence site lattice frequency and grain size decreases in the following sequence, 10% compression > 15% compression > 5% compression, except for 700 0C. During thermomechanical treatments of copper, strain-induced grain boundary migration and grain growth may occur during annealing of 5% compressed copper, and recrystallization dominates during annealing of 15% compressed copper, while the annealing mechanism of 10% compressed copper changes from strain-induced grain boundary migration and grain growth to recrystallization when the annealing temperature exceeds 600 0C. The results indicated that during single-step low-strain thermomechanical treatments, straininduced grain boundary migration and grain growth would gradually change to recrystallization with the increase of pre-deformation level and annealing temperature. Among the three mechanisms, strain-induced grain boundary migration seems to be more effective than recrystallization and grain growth in the optimization of grain boundary character distribution, and it is suggested that this is due to the high boundary migration rate of strain-induced grain boundary migration.


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