Grain-boundary structure effects on intergranular stress corrosion cracking of alloy X-750

Pan, Yu; Adams, Brent L.; Olson, Tamara; Panayotou, N.F.

doi:10.1016/s1359-6454(96)00125-5

Cited by 156 publications

(77 citation statements)

References 15 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…This technique, sometimes termed Orientation Imaging Microscopy (OIM) [1], has been used to perform statistical characterizations of grain boundaries (for example see [2][3][4][5]). Most of these studies have focused on misorientation relationships.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Advanced Characterization of Twins Using Automated Electron Backscatter Diffraction

Wright¹,

Bingert²,

Mason³

et al. 2002

MSF

View full text Add to dashboard Cite

Abstract. This paper describes results obtained using an automated, crystallographically-based technique for twin identification. The technique is based on the automated collection of spatially specific orientation measurements by electron backscatter diffraction (EBSD) in the scanning electron microscope (SEM). The key features of the analysis are identification of potential twin boundaries by their misorientation character, identification of the distinct boundary planes among the symmetrically equivalent candidates, and validation of these boundaries through comparison with the boundary and twin plane traces in the sample cross section. Results on the application of this technique to deformation twins in zirconium are analyzed for the effect of twin type and amount and sense of uniaxial deformation. The accumulation of strain tends to increase the misorientation deviation at least to the degree of the trace deviation compared with recrystallization twins in nickel. In addition to the results on characterizing the twin character, results on extending the twin analysis to automated identification of parent and daughter material for structures exhibiting twin deformation are reported as well.

show abstract

Section: Introductionmentioning

confidence: 99%

“…The orientation of individual grain boundary planes can be measured using either serial sectioning [5] or by observation of grain boundaries appearing on two mutually perpendicular sections [7] (i.e. at the sample edges).…”

Section: Introductionmentioning

confidence: 99%

Advanced Characterization of Twins Using Automated Electron Backscatter Diffraction

Wright¹,

Bingert²,

Mason³

et al. 2002

MSF

View full text Add to dashboard Cite

show abstract

“…However, corrosion of aluminum alloys also limits their usage in these areas, especially for marine structures. Numerous studies have been carried out to improve the corrosion resistance of such alloys (Kim et al, 2001;Lo et al, 2009;Pan et al, 1996;Yuan, 2006).…”

Section: Intergranular Corrosion Of Aluminum Alloysmentioning

confidence: 99%

“…It occurs between adjacent grain bodies, and different alloys show various electrochemically active paths for IGC. Pan et al (1996) and well studied the property and behavior of grain boundaries and concluded that they are strongly affected by local chemistry and atomic structures. The only GBC parameter considered correlating to IGC is misorientation (denoted as θ).…”

Section: Grain Boundary Characteristicsmentioning

confidence: 99%

“…For AA5XXX-series alloys, the susceptibility to IGC is quantitatively measured by ASTM-G67 standard test, known as the Nitric Acid Mass Loss Test (NAMLT). Pan et al (1996) and Unwin and Nicholson (1969) used transmission electron microscopy (TEM) to study the properties of grain boundary precipitation as a function of quench rate and treatment temperature. They concluded that the precipitation was strongly affected by local chemistry and atomic structures.…”

Section: Background Of the Intergranular Corrosion Problemmentioning

confidence: 99%

See 1 more Smart Citation

Image Fusion and An Outler Detection Framework for Hierarchical Modeling with Application to Corrosion Prediction

Chen¹

View full text Add to dashboard Cite

Semi-continuous data appear frequently in many scientific fields which is a special type of data which include a number of continuous data with reoccurrences of some discrete numbers. For example, in epidemiology studies, data often include both zeros for those areas without certain disease, and positive values indicating the severity degree of the diagnosed epidemic cases in other places. Such data often include outliers and errors from the experiment and the measurement, which are not preventable.Modeling the semi-continuous data in the presence of noise is challenging because of the appearance of outliers and the skewness from the normal distribution within the data. Both of them may mislead the modeling result. It is imperative to model problems with such data, but available techniques are very limited.This dissertation aims to develop a formal methodology using supervised learning when: (1) relevant information is stored in a series of images; (2) images are usually noisy and distorted from each other; (3) the data set for modeling is a data set with a semi-continuous response variable; and (4) the modeling goal is to understand the causal mechanism between variables and to predict future events accurately. The developed methodology includes three models for this objective: an image fusion algorithm, an outlier detection framework and a two-part generalized hierarchical model for semi-continuous data. They have been applied to a real corrosion problem and modeling results showed that this methodology solved this problem effectively.Corrosion data were efficiently extracted from corrosion images, outliers within the extracted data were detected and treated properly and most importantly, the underlying causal mechanisms between material microstructures and corrosion evolution i ii were revealed by the generalized hierarchical model. Four major contributions have been made: a supervised learning methodology is constructed for problems with information stored in both semi-continuous data and a series of noisy images; an outlier detection framework for supervised learning is constructed to enhance prediction accuracy; an image fusion algorithm is designed to extract and combine information from multiple noisy images, and the estimation of the generalized hierarchical model helps material scientists to reveal the causal mechanisms between grain boundary characteristics and the intergranular corrosion, as well as to predict future corrosion occurrences. Future works of this dissertation are discussed at last.

show abstract

High‐resolution analytical electron microscopy characterization of corrosion and cracking at buried interfaces

Bruemmer

Thomas

2001

Surface & Interface Analysis

View full text Add to dashboard Cite

Recent results are presented demonstrating the application of cross-sectional analytical transmission electron microscopy (ATEM) to corrosion and cracking in high-temperature water environments. Microstructural, chemical and crystallographic characterization of buried interfaces at near-atomic resolutions is shown to reveal evidence for unexpected local environments, corrosion reactions and material transformations. Information obtained by a wide variety of high-resolution imaging and analysis methods indicates the processes occurring during crack advance and provides insights into the mechanisms controlling environmental degradation. Examples of intergranular attack and cracking in type 316 austenitic stainless steel and Ni-based alloy 600 are presented to illustrate the potential for this approach. The presence of deeply attacked grain boundaries off the main cracks, revealed by TEM, is believed to indicate a major role of active corrosion in the stress corrosion cracking (SCC) process. Corroded boundaries were filled with oxides to the leading edges of attack. Analyses of the oxide films and impurities in the narrow intergranular penetrations and crack tips with widths of 10 nm or less indicate influences of the grain boundary characteristics and water chemistry. Boundary and precipitate corrosion structures can be used to identify the local electrochemistry promoting degradation in complex service environments. Solution impurities such as lead are found in high concentrations at nanometer-wide reaction zones in samples from secondary water environments, indicating water access at leading edges of the attack and the influence of these impurities on the corrosion processes. Results for specific samples are used to demonstrate the ability of cross-sectional ATEM to reveal new details of buried corrosion structures that cannot be detected by other methods.

show abstract

Grain-boundary structure effects on intergranular stress corrosion cracking of alloy X-750

Cited by 156 publications

References 15 publications

Advanced Characterization of Twins Using Automated Electron Backscatter Diffraction

Advanced Characterization of Twins Using Automated Electron Backscatter Diffraction

Image Fusion and An Outler Detection Framework for Hierarchical Modeling with Application to Corrosion Prediction

High‐resolution analytical electron microscopy characterization of corrosion and cracking at buried interfaces

Contact Info

Product

Resources

About