Texture and Grain Boundary Character Distribution in a Thermomechanically Processed OFHC Copper

2011 ◽  
Vol 134 (1) ◽  
Author(s):  
Khaled J. Al-Fadhalah
Keyword(s):  
Grain Boundary ◽  
Grain Growth ◽  
Boundary Migration ◽  
Recrystallization Annealing ◽  
Grain Boundary Character Distribution ◽  
Boundary Character ◽  
Special Boundaries ◽  
Grain Boundary Character ◽  
Character Distribution ◽  
Boundary Character Distribution

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.

Optimization of the grain boundary character distribution of pure copper by low-strain thermomechanical processing

2020 ◽  
Vol 111 (8) ◽  
pp. 668-675
Author(s):  
Ming Huang ◽  
Kunpeng Zhao ◽  
Ziyun Chen ◽  
Yuan Qin ◽  
Xinye Yang ◽  
...  
Keyword(s):  
Grain Boundary ◽  
Grain Growth ◽  
Boundary Migration ◽  
Pure Copper ◽  
Grain Boundary Character Distribution ◽  
Grain Boundary Migration ◽  
Boundary Character ◽  
Grain Boundary Character ◽  
Character Distribution ◽  
Boundary Character Distribution

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.

Selective Grain Growth and Grain Boundary Character Distribution Relationships in Magnetostrictive Fe-Ga Thin Sheets

2018 ◽  
Vol 917 ◽  
pp. 223-227
Author(s):  
Suok Min Na ◽  
Nicholas J. Jones ◽  
Alison B. Flatau
Keyword(s):  
Grain Boundary ◽  
Grain Growth ◽  
Secondary Recrystallization ◽  
High Energy ◽  
Grain Boundary Character Distribution ◽  
Rolled Sheet ◽  
Boundary Character ◽  
Grain Boundary Character ◽  
Character Distribution ◽  
Boundary Character Distribution

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.

SEM-ECP Analysis of Grain-Boundary Character Distribution in Polycrystalline Materials

1996 ◽  
Vol 54 ◽  
pp. 354-355
Author(s):  
Tadao Watanabe
Keyword(s):  
Grain Boundary ◽  
Grain Boundaries ◽  
Boundary Migration ◽  
Polycrystalline Materials ◽  
Grain Boundary Character Distribution ◽  
Boundary Character ◽  
Grain Boundary Character ◽  
Character Distribution ◽  
Boundary Character Distribution

As demonstrated early 1980’s (1), the scanning electron rnicrocopy-electron channelling pattern (SEM-ECP) technique is very powerful in determination of orientation of individual grains and the character of grain boundaries in polycrystalline materials. Figure 1(a) and (b) show SEM and ECP images of a grain boundary in polycrystal line iron-6.5 mass % silicon ribbon produced by rapid solidification and subsequent annealing. We can intuitively recognize from the SEM-ECP image that the character of the boundary is of <100> tilt type with about 7° misorientation angle. This kind of direct observation is very useful for a study of grain boundary migration and grain growth.This paper discusses advantages of the SEM-ECP technique for the precise determination of the character of grain boundary and for statistical analysis of grain boundaries to bridge roles of individual grain boundaries and bulk properties in a polycrystal. The new microstructural parameter associated with grin boundary termed “grain boundary character distribution (GBCD)” which was introduced by the present author (2,3) and has been utilized in designing and engineering grain boundaries in order to produce desirable and/or high bulk performance in polycrystalline materials (4,5). GBCD describes the type and the frequency of different types of grain boundaries, ie. random general boundaries and special boundaries like low-angle boundaries and low Σ coincidence boundaries.

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