Dislocation structures in cyclically deformed nickel polycrystals

Buque, Cesar; Bretschneider, J.; Schwab, A.; Holste, C.

doi:10.1016/s0921-5093(00)01784-6

Cited by 81 publications

(34 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…During the deformation, the torque and therefore the flow stress developes in a different way as described in section 3.1. As can be seen in Fatigue of nickel and Armco-iron was investigated in many studies, see for example [31,32,33,34,35]. The presented cyclic hardening curves in these studies show similar characteristics like the measured curves in the present investigation.…”

Section: Severe Plastic Deformationsupporting

confidence: 86%

Cyclic high-pressure torsion of nickel and Armco iron

Wetscher

Pippan

2006

Philosophical Magazine

View full text Add to dashboard Cite

Section: Severe Plastic Deformationsupporting

confidence: 86%

Cyclic high-pressure torsion of nickel and Armco iron

Wetscher

Pippan

2006

Philosophical Magazine

View full text Add to dashboard Cite

“…of the dislocation arrangements in the composite of PSBs and matrix. In this context, Buque et al [33][34][35] investigated the influence of individual grain orientations as well as of the grain size on the occurring dislocation arrangements and the macroscopic heterogeneity of plastic deformation. The authors showed that the following four groups of dislocation arrangement patterns can be introduced and are sufficient in order to describe the high variety of dislocation configurations after cyclic deformation at different plastic strain amplitudes: (i) labyrinth structure, (ii) fragmented wall structure, (iii) bundle structure and (iv) patch structure.…”

Section: Imaging Of Dislocation Arrangements After Fatiguementioning

confidence: 99%

“…The "ladder-like" arrangement of dislocation walls is then turned into a pronounced cell structure. Imaging of PSBs by ECCI is mainly useful for the determination of parameters like dislocation wall thickness and channel width [102] or the dependence of the PSB formation on the crystallographic orientation and/or grain size [103] due to the good statistics, which can be achieved by this method. Another aspect for which the ECC imaging can be used is the investigation of the activation of cyclic slip within the PSBs [62].…”

Section: Ecci and The Slip Activity Of Psbsmentioning

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

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

“…This is observed whatever the metallic material (Cu [5,3,18], Ni [16], 316L [19]). Let us first consider grains oriented for single slip.…”

Section: Effect Of Slip Planarity Imposed To Grains Oriented For Singmentioning

confidence: 86%

“…The case of nickel was extensively studied [13][14]16] as well as the one of copper. For these orientations, the dislocation microstructures are often made of labyrinths and cells/walls respectively, which differ from the persistent slip band microstructure usually observed for crystals oriented for single slip (figure 1).…”

Section: Additional Effect Of Hardening Laws Based the Csscs Of Crystmentioning

confidence: 99%