Morphology Evolution of Grain Boundary Carbides in Highly Twinned Inconel Alloy 600

2016 ◽  
Vol 879 ◽  
pp. 1111-1116 ◽  
Author(s):  
Hui Li ◽  
Jiao Rong Ma ◽  
Xin Rong Liu ◽  
Shuang Xia ◽  
Wen Qing Liu ◽  
...  

The effects of grain boundary characters on the morphology evolution of grain boundary carbides in Inconel Alloy 600 with high proportional low Σ coincidence site lattice (CSL) boundaries aged at 715 oC for 1-100 h were investigated by scanning electron microscopy (SEM) and electron backscatter diffraction (EBSD). During the aging process, the carbides precipitated at coherent twin (Σ3) boundaries are very few and finest within all the aging time. Bar like carbides precipitated near both sides of the incoherent twin (Σ3) boundaries, and bigger carbides than that of coherent Σ3 boundaries had been found on the incoherent Σ3 boundaries. Bar like carbides precipitated near only one side of Σ9 boundaries, and much bigger carbides than that of Σ3 boundaries have been found on the Σ9 boundaries. The morphology of carbides precipitated at Σ27 and random grain boundaries are similar, and is bigger than that of precipitated at other grain boundaries. The carbides precipitated at grain boundaries with all types grow bigger with the aging time prolonging, but their growth rates are different.

2000 ◽  
Vol 6 (S2) ◽  
pp. 940-941
Author(s):  
A.J. Schwartz ◽  
M. Kumar ◽  
P.J. Bedrossian ◽  
W.E. King

Grain boundary network engineering is an emerging field that encompasses the concept that modifications to conventional thermomechanical processing can result in improved properties through the disruption of the random grain boundary network. Various researchers have reported a correlation between the grain boundary character distribution (defined as the fractions of “special” and “random” grain boundaries) and dramatic improvements in properties such as corrosion and stress corrosion cracking, creep, etc. While much early work in the field emphasized property improvements, the opportunity now exists to elucidate the underlying materials science of grain boundary network engineering. Recent investigations at LLNL have coupled automated electron backscatter diffraction (EBSD) with transmission electron microscopy (TEM)5 and atomic force microscopy (AFM) to elucidate these fundamental mechanisms.An example of the coupling of TEM and EBSD is given in Figures 1-3. The EBSD image in Figure 1 reveals “segmentation” of boundaries from special to random and random to special and low angle grain boundaries in some grains, but not others, resulting from the 15% compression of an Inconel 600 polycrystal.


2013 ◽  
Vol 46 (2) ◽  
pp. 483-492 ◽  
Author(s):  
Mariusz Jedrychowski ◽  
Jacek Tarasiuk ◽  
Brigitte Bacroix ◽  
Sebastian Wronski

The main aim of the present work is to study the relation between microstructural features – such as local misorientations, grain orientation gradients and grain boundary structures – and thermomechanical treatment of hexagonal zirconium (Zr702α). Electron backscatter diffraction (EBSD) topological maps are used to analyze the aforementioned material parameters at the early stages of plastic deformation imposed by channel-die compression, as well as at a partial recrystallization state achieved by brief annealing. The evolution of local misorientations and orientation gradients is investigated using the so-called kernel average misorientation (KAM) and grain orientation spread (GOS) statistics implemented in the TSLOIMdata analysis software [TexSEM Laboratories (2004), Draper, UT, USA]. In the case of grain boundaries (GBs) a new method of analysis is presented. As an addition to the classical line segments method, where the grain boundary is represented by line segments that separate particular pairs of neighboring points, an approach that focuses on grain boundary areas is proposed. These areas are represented by sets of EBSD points, which are specially selected from a modified calculation procedure for the KAM. Different evolution mechanisms of intragranular boundaries, low-angle grain boundaries and high-angle grain boundaries are observed depending on the compression direction. The observed differences are consistent with the results obtained from KAM and GOS analysis. It is also concluded that the proposed method of grain boundary characterization seems to be promising, as it provides new and interesting analysis tools such as textures, absolute fractions and other EBSD statistics of the GB areas. This description may be more compatible with a real deformed microstructure, especially for grain boundaries with very small misorientation, which are indeed clustered areas of lattice defect accumulation.


2007 ◽  
Vol 539-543 ◽  
pp. 3389-3394 ◽  
Author(s):  
Wei Guo Wang

The progress of grain boundary engineering (GBE) is overviewed and the challenges for further investigations emphasized. It points out that, the electron backscatter diffraction (EBSD) reconstruction of grain boundaries, which gives the information of connectivity interruption of general high angle boundaries (HABs), is more significant than purely pursuing high frequency of so-called special boundaries. The criterion for the optimization of grain boundary character distribution (GBCD) needs to be established. The energy spectrum and the degradation susceptibility of grain boundaries of various characters including HABs and low Σ(Σ≤29) coincidence site lattice (CSL) needs to be studied and ascertained. And finally, the newly proposed model of non-coherent Σ3 interactions for GBCD optimization are discussed.


2015 ◽  
Vol 21 (4) ◽  
pp. 927-935 ◽  
Author(s):  
Matthew M. Nowell ◽  
Michael A. Scarpulla ◽  
Naba R. Paudel ◽  
Kristopher A. Wieland ◽  
Alvin D. Compaan ◽  
...  

AbstractThe performance of polycrystalline CdTe photovoltaic thin films is expected to depend on the grain boundary density and corresponding grain size of the film microstructure. However, the electrical performance of grain boundaries within these films is not well understood, and can be beneficial, harmful, or neutral in terms of film performance. Electron backscatter diffraction has been used to characterize the grain size, grain boundary structure, and crystallographic texture of sputtered CdTe at varying deposition pressures before and after CdCl2 treatment in order to correlate performance with microstructure. Weak fiber textures were observed in the as-deposited films, with (111) textures present at lower deposition pressures and (110) textures observed at higher deposition pressures. The CdCl2-treated samples exhibited significant grain recrystallization with a high fraction of twin boundaries. Good correlation of solar cell efficiency was observed with twin-corrected grain size while poor correlation was found if the twin boundaries were considered as grain boundaries in the grain size determination. This implies that the twin boundaries are neutral with respect to recombination and carrier transport.


2007 ◽  
Vol 263 ◽  
pp. 207-212 ◽  
Author(s):  
Vĕra Rothová ◽  
Jiří Buršík ◽  
Milan Svoboda ◽  
Jiří Čermák

Grain boundary self-diffusion in both the cast and the cold-rolled Puratronic 4N5 nickel was studied in the temperature range from 600 °C to 1000 °C. The experiments were carried out with the samples pre-annealed at 1100 °C in comparison to the samples pre-annealed at intended individual diffusion temperatures. The relative grain orientation was analyzed on the same samples by means of electron backscatter diffraction (EBSD) and grain boundaries (GBs) were characterized in terms of the coincidence site lattice (CSL) model. Considering the non-linear Arrhenius temperature dependencies obtained for most specimens by using conventional method of profile evaluation in the B-type kinetics and the appearance of two high-diffusivity paths in diffusion profiles measured, a more suitable BB-type and AB-type diffusion models were applied for data evaluation.


2013 ◽  
Vol 652-654 ◽  
pp. 929-933 ◽  
Author(s):  
Xin Li Song ◽  
Kun Peng ◽  
P.P. Zhang ◽  
J.Y. Wu ◽  
J. Zhou ◽  
...  

The effect of phosphorus contents on texture and grain boundaries character for the high strength Ti-IF annealed for 120sec at 810oC are researched by electron backscatter diffraction technique(EBSD). The recrystallization texture is approximated by the γ-fiber texture whose components are {111} and {111} orientation texture. The highest volume fraction of //ND texture is almost 80% for the sample containing 0.056%P. A large amount of coincidence site lattice(CSL) grain boundaries ∑3,∑5, ∑7,∑9,∑11 and ∑13b are obtained.


2012 ◽  
Vol 706-709 ◽  
pp. 2605-2610
Author(s):  
L. Chen ◽  
G.J. Yuan ◽  
J.G. Xu ◽  
F. Guo ◽  
N. Pang

The effect of trench aspect ratio and line spacing on microstructure and texture in annealed damascene Cu interconnects has been investigated. The X-ray diffraction (XRD) and electron backscatter diffraction (EBSD) analyses of Cu lines, showed a preferred {111} orientation and the trenches reduce the proportion of high-angle grain boundaries and increase the fraction of coincidence site lattice (CSL) grain boundaries, comparing with the Cu blanket film. In addition, both trench aspect ratio and line spacing can largely affect the microstructure and texture in annealed damascene Cu interconnects.


2011 ◽  
Vol 127 ◽  
pp. 89-94 ◽  
Author(s):  
Ye Chao Zhu ◽  
Jiong Hui Mao ◽  
Fa Tang Tan ◽  
Xue Liang Qiao

Low energy grain boundaries were considered to be important in abnormal grain growth by theoretical deduction. The disorientation angles and coincidence site lattice grain boundaries distribution of more than 20 Goss grains and their neighboring matrix grains in primary recrystallized Fe-3%Si alloy were investigated using an electron backscatter diffraction method. It was found that the frequency of low energy grain boundaries of Goss grains which are more likely to abnormally grow are higher than their neighboring matrix grains, which indicated that low energy grain boundaries play a dominant role in the abnormal grain growth of Fe-3%Si alloy. The result meets well with the abnormal grain growth theory.


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