Low energy dislocation structures produced by cyclic deformation

Laird, C.; Charsley, P.; Mughrabi, H.

doi:10.1016/0025-5416(86)90281-8

Cited by 362 publications

(86 citation statements)

References 57 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[84,85]) or in copper (cf. [86,87]), the arrangement of dislocations is not in such a clear "ladder-like" structure. An example for the dislocation arrangement at an early stage of cyclic deformation of a 316L specimen is shown in Figure 9(a).…”

Section: Planar Dislocation Arrangement At Early State Of Fatiguementioning

confidence: 97%

“…It is known from the literature [86,91] that the dislocation arrangements in fcc metals and alloys strongly depend on the plastic strain amplitude and SFE resulting partly in a transition from planar to cross slip behaviour. A well-known example for this behaviour is the austenitic stainless steel AISI 316L.…”

Section: Transition From Planar Glide To Cross Slip Behaviourmentioning

confidence: 99%

See 1 more Smart Citation

Case studies on the application of high-resolution electron channelling contrast imaging – investigation of defects and defect arrangements in metallic materials

Weidner

Biermann

2015

Philosophical Magazine

View full text Add to dashboard Cite

In 1967, Coates discovered the electron channelling contrast of backscattered electrons (BSEs) in scanning electron microscopy, and by this the possibility to investigate arrangements of lattice defects in deformed microstructures of materials. Since that time, a straightforward development of the scanning electron microscopes as well as of the electron channelling contrast technique took place. Nowadays, the performance of scanning electron microscopes is high enough that the resolution of electron channelling contrast imaging (ECCI) micrographs is comparable with conventional bright field transmission electron microscopy (TEM) micrographs. In the first part of the present paper, a historical review on the development of the ECCI technique starting from its discovery more than 45 years ago up to the combination with other advanced methods of scanning electron microscopy like electron backscatter diffraction or high-resolution selected area channelling patterning in the last few years is given. Major important investigations using this technique for the visualization of individual lattice defects like stacking faults (SFs) and dislocations or dislocation arrangements are chronologically summarized. The second part demonstrates that nowadays, ECCI micrographs taken in high-resolution scanning electron microscopes can be called high-resolution ECCI (HR-ECCI). It is shown that the resolution of individual SFs and dislocations in the HR-ECCI micrographs is comparable to that of conventional TEM (about 15 nm defect image width). Furthermore, the paper is demonstrating that HR-ECCI micrographs can be obtained for various types of materials after different mechanical loadings and different grain sizes ranging from large grain size of 500 μm (cast steel) down to less than 2 μm (γ-TiAl).

show abstract

Section: Planar Dislocation Arrangement At Early State Of Fatiguementioning

confidence: 97%

Section: Transition From Planar Glide To Cross Slip Behaviourmentioning

confidence: 99%

Case studies on the application of high-resolution electron channelling contrast imaging – investigation of defects and defect arrangements in metallic materials

Weidner

Biermann

2015

Philosophical Magazine

View full text Add to dashboard Cite

show abstract

“…Obviously, the well-developed DBII must have evolved from the developing one through the linking of dislocation rungs. As shown in Figs 2 and 3, the microstructure of the DB is always characterized by the ladder-like PSBs or parallel walls, which are the typical low-energy dislocations (LEDs) proposed by Laird et al [2] and KuhlmannWilsdorf [15]. These LEDs within the DBs may enjoy priority in the plastic strain localization and then in the initiation of fatigue cracks.…”

Section: Crystallographic Characteristics Of Dbsmentioning

confidence: 89%

“…To reveal the fatigue damage mechanisms of metallic materials, several workers, in past decades, have made great contributions to the microstructural evolution and damage mechanisms of fatigued crystalline materials, typically copper single crystals. There are presently a wealth of experimental data and several excellent review articles concerning different aspects of the subject [1][2][3][4]. By plotting the saturation stress t s versus the applied plastic strain amplitude g pl , Mughrabi [5] proposed the well-known cyclic stress-strain curve (CSSC) of copper single crystals with singleslip orientation.…”

Section: Introductionmentioning

confidence: 99%

“…As the applied strain amplitude reaches region C, the saturation stress t s of the copper single crystal increases again with increasing strain amplitude. This stage has been characterized by the activation of secondary slip systems and the subsequent formation of cell and labyrinth dislocation structures [1][2][3][4][5]. However, the deformation and damage mechanisms of the copper single crystals cyclically deformed in this region of higher plastic strain amplitudes have not been well documented so far.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Evolution and microstructural characteristics of deformation bands in fatigued copper single crystals

2001

View full text Add to dashboard Cite

Sensitivity of Ultrasonic Attenuation and Velocity Change to Cyclic Deformation in Pure Aluminum

Wang

Fang

Zhang

1998

phys. stat. sol. (a)

View full text Add to dashboard Cite

The average dislocation density Λ and loop length L in cyclically deforming Al were derived from the measurement of ultrasonic attenuation and velocity change. With the increase of the cycle number, Λ increases at first and then decreases a little after passing a maximum, while L decreases monotonously. At low cyclic strain amplitudes less than 10—4, and L Λ almost do not change with cycle number. These results show that the measurement of ultrasonic attenuation and velocity change is a useful method to determine the parameters Λ and L in the process of cyclic deformation.

show abstract

Low energy dislocation structures produced by cyclic deformation

Cited by 362 publications

References 57 publications

Case studies on the application of high-resolution electron channelling contrast imaging – investigation of defects and defect arrangements in metallic materials

Case studies on the application of high-resolution electron channelling contrast imaging – investigation of defects and defect arrangements in metallic materials

Evolution and microstructural characteristics of deformation bands in fatigued copper single crystals

Sensitivity of Ultrasonic Attenuation and Velocity Change to Cyclic Deformation in Pure Aluminum

Contact Info

Product

Resources

About