Experimental Evaluation of the Cyclic Slip Irreversibility Factor

Cyclic slip irreversibility is one of the most important features of fatigue processes in ductile metals because it induces surface relief evolutions during cycling which are mainly responsible for crack initiation. The reversible and irreversible parts of the slip within persistent slip bands (PSBs) in polycrystalline nickel are measured directly after half-cycle deformation and one full cycle on specimen surfaces once more well-polished after 60% of fatigue life using atomic force microscopy (AFM) and different techniques of scanning electron microscopy as electron channelling contrast imaging and electron backscattered diffraction. Using AFM measures on the same slip steps after half-cycle and full cycle, the cyclic slip irreversibility factor is directly evaluated and discussed with respect to the literature.

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The Half-Cycle Slip Activity of Persistent Slip Bands in Polycrystals

Materials Science Forum ◽

10.4028/www.scientific.net/msf.567-568.123 ◽

2007 ◽

Vol 567-568 ◽

pp. 123-127 ◽

Cited By ~ 2

Author(s):

A. Weidner ◽

W. Tirschler ◽

C. Blochwitz ◽

Werner Skrotzki

Keyword(s):

Volume Fraction ◽

Half Cycle ◽

Slip Systems ◽

Large Scatter ◽

Force Microscopy ◽

Atomic Force ◽

Slip Bands ◽

Slip Activity ◽

Persistent Slip Bands ◽

Number Of Cycles

The development of the volume fraction of cumulated persistent slip bands (PSBs) in cyclically deformed nickel polycrystals was investigated in dependence on the number of cycles using scanning electron microscopy (SEM) and atomic force microscopy (AFM). It was shown that there is a large scatter of the volume fraction of PSBs from grain to grain. Three different tendencies for the development of the volume fraction with increasing number of cycles were distinguished. It was shown that there is a correlation of the orientation of the primary slip systems with the volume fraction of cumulated PSBs and the activation of PSBs during half-cycle deformation.

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Fault Isolation of MOL and FEOL Buried Defects Using Conductive Atomic Force Microscopy as a Complement to Passive Voltage Contrast Imaging

ISTFA 2017: Conference Proceedings from the 43rd International Symposium for Testing and Failure Analysis ◽

10.31399/asm.cp.istfa2017p0606 ◽

2017 ◽

Author(s):

Lucile C. Teague Sheridan ◽

Linda Conohan ◽

Chong Khiam Oh

Keyword(s):

Atomic Force Microscopy ◽

Cmos Technology ◽

Fault Isolation ◽

Contrast Imaging ◽

Conductive Atomic Force Microscopy ◽

Isolation Technique ◽

Conductive Afm ◽

Force Microscopy ◽

Atomic Force ◽

Voltage Contrast

Abstract Atomic force microscopy (AFM) methods have provided a wealth of knowledge into the topographic, electrical, mechanical, magnetic, and electrochemical properties of surfaces and materials at the micro- and nanoscale over the last several decades. More specifically, the application of conductive AFM (CAFM) techniques for failure analysis can provide a simultaneous view of the conductivity and topographic properties of the patterned features. As CMOS technology progresses to smaller and smaller devices, the benefits of CAFM techniques have become apparent [1-3]. Herein, we review several cases in which CAFM has been utilized as a fault-isolation technique to detect middle of line (MOL) and front end of line (FEOL) buried defects in 20nm technologies and beyond.

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MORPHOLOGICAL AND NANOMECHANICAL INVESTIGATIONS OF MAGNEVIST NANO-ENCAPSULATED DENDRIMERS BY ATOMIC FORCE MICROSCOPY

The Libyan Journal of Pharmacy and Clinical Pharmacology ◽

10.5542/ljpcp.v1i0.48154 ◽

2012 ◽

Vol 1 ◽

Author(s):

Hosam Gharib Abdelhady

Keyword(s):

Mechanical Properties ◽

Atomic Force Microscopy ◽

Magnetic Resonance ◽

Magnetic Resonance Images ◽

Spherical Particles ◽

Contrast Imaging ◽

Force Microscopy ◽

Atomic Force ◽

Polyamidoamine Dendrimers ◽

Molecular Morphology

Objectives: This research aims at investigating the effect of nano-encapsulating the MagnevistTM, a magnetic resonance imaging agent, within generation four, 1, 4- diaminobutane core polyamidoamine dendrimers on their molecular morphology and their nano-mechanical properties in liquid.Methods: Atomic force microscopy was applied in its imaging and force measuring modes to investigate, on the molecular scale, the morphological and nano-mechanical changes in generation four, 1, 4-diaminobutane core polyamidoamine dendrimers due to the nano-encapsulation of Magnevist in liquid.Results: The weight gain of dendrimers indicates the loading of ~ 30 Magnevist molecules. This has increased the rigidity of the dendrimer molecules, compared to unloaded dendrimers. Atomic force microscopy showed individual well-defined nano-spherical particles with nanoscopic dimensions of (40±13 nm in diameter and 4.38±0.54 nm in height). In contrast, imaging of non encapsulated dendrimers revealed loose aggregates of 15±3.5 nm in diameter and 0.9±0.2 nm in height.Conclusions: The atomic force microscopy, in liquid, was successfully applied to differentiate between Magnevist nano-encapsulated and non-encapsulated dendrimers, in their morphology and in their nano-mechanical properties. The results confirm the nano-encapsulation of Magnevist within generation four, 1,4-diaminobutane core polyamidoamine dendrimers. This loading increased the rigidity of the nanoencapsulated dendrimer, packed ~ 9 Magnevist-G 4 molecules together and may probably enhance the magnetic resonance images and increase their duration of time in the bloodstream when compared with Magnevist alone. Thus elongating the imaging sessions without the need for additional contrast agent doses.

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Phase Contrast Imaging in Atomic Force Microscopy

Microscopy and Microanalysis ◽

10.1017/s143192760001326x ◽

1997 ◽

Vol 3 (S2) ◽

pp. 1275-1276

Author(s):

Sergei Magonov

Keyword(s):

Atomic Force Microscopy ◽

Phase Contrast ◽

Phase Changes ◽

Phase Imaging ◽

Phase Detection ◽

Contrast Imaging ◽

Force Microscopy ◽

Atomic Force ◽

Resonance Frequencies ◽

Soft Samples

Phase detection in TappingMode™ enhances capabilities of Atomic Force Microscopy (AFM) for soft samples (polymers and biological materials). Changes of amplitude and phase changes of a fast oscillating probe are caused by tip-sample force interactions. Height images reflect the amplitude changes, and in most cases they present a sample topography. Phase images show local differences between phases of free-oscillating probe and of probe interacting with a sample surface. These differences are related to the change of the resonance frequency of the probe either by attractive or repulsive tip-sample forces. Therefore phase detection helps to choose attractive or repulsive force regime for surface imaging and to minimize tip-sample force. For heterogeneous materials the phase imaging allows to distinguish individual components and to visualize their distribution due to differences in phase contrast. This is typically achieved in moderate tapping, when set-point amplitude, Asp, is about half of the amplitude of free-oscillating cantilever, Ao. In contrast, light tapping with Asp close to Ao is best suited for recording a true topography of the topmost surface layer of soft samples. Examples of phase imaging of polymers obtained with a scanning probe microscope Nanoscope® IIIa (Digital Instruments). Si probes (225 μk long, resonance frequencies 150-200 kHz) were used.

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High Contrast Imaging of Interphases in Ternary Polymer Blends Using Focused Ion Beam Preparation and Atomic Force Microscopy

Macromolecules ◽

10.1021/ma0482664 ◽

2005 ◽

Vol 38 (6) ◽

pp. 2368-2375 ◽

Cited By ~ 27

Author(s):

Nick Virgilio ◽

Basil D. Favis ◽

Marie-France Pépin ◽

Patrick Desjardins ◽

Gilles L'Espérance

Keyword(s):

Atomic Force Microscopy ◽

Polymer Blends ◽

Focused Ion Beam ◽

Ion Beam ◽

High Contrast ◽

Contrast Imaging ◽

Force Microscopy ◽

Atomic Force ◽

High Contrast Imaging ◽

Ternary Polymer

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Study of deformation relief of polycrystalline nickel by atomic force microscopy

10.1063/5.0034258 ◽

2020 ◽

Author(s):

G. V. Shlyakhova ◽

M. V. Nadezhkin ◽

S. A. Barannikova ◽

L. B. Zuev

Keyword(s):

Atomic Force Microscopy ◽

Polycrystalline Nickel ◽

Force Microscopy ◽

Atomic Force ◽

Deformation Relief

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Half-cycle slip activity of persistent slip bands at different stages of fatigue life of polycrystalline nickel

Materials Science and Engineering A ◽

10.1016/j.msea.2008.03.027 ◽

2008 ◽

Vol 492 (1-2) ◽

pp. 118-127 ◽

Cited By ~ 27

Author(s):

A. Weidner ◽

J. Man ◽

W. Tirschler ◽

P. Klapetek ◽

C. Blochwitz ◽

...

Keyword(s):

Fatigue Life ◽

Half Cycle ◽

Cycle Slip ◽

Polycrystalline Nickel ◽

Slip Bands ◽

Slip Activity ◽

Persistent Slip Bands

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Orientation Dependence of Photochemical Reduction Reactions on SrTiO3 Surfaces

MRS Proceedings ◽

10.1557/proc-751-z2.4 ◽

2002 ◽

Vol 751 ◽

Cited By ~ 3

Author(s):

Jennifer L. Giocondi ◽

Gregory S. Rohrer

Keyword(s):

Photochemical Activity ◽

Orientation Dependence ◽

Reaction Site ◽

Electron Backscattered Diffraction ◽

Photochemical Reduction ◽

Force Microscopy ◽

Atomic Force ◽

Individual Grains ◽

Silver Metal ◽

Silver Cations

ABSTRACTPolished and annealed surfaces of randomly oriented crystallites were used to study the orientation dependence of the photochemical activity of SrTiO3 surfaces. Silver cations reduced from an aqueous solution produce solid silver metal at the reaction site. The amounts of silver produced by a fixed exposure were used as a relative measure of each grain's activity. The surface structure of the grains was observed using atomic force microscopy and the surface orientation of each grain was determined by electron backscattered diffraction. Surfaces annealed in air for 6h at 1200° C were bound by some combination of the following three planes: {110}, {111}, and a complex facet inclined approximately 24° from {100}. By correlating the orientations of individual grains to the amount of deposited silver, we conclude that surfaces with the complex {100} facet are the most active.

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