Focused Ion Beam as New Tool for Local Investigations of the Interaction of Microcracks with Grain Boundaries

This paper reports the effects of thermal aging between 650 and 850 °C on the localized corrosion behavior of lean duplex stainless steel (LDSS 2404). Critical pitting temperature (CPT) and double loop electrochemical potentiokinetic reactivation (DL-EPR) tests were performed. The localization of pitting attack and intergranular corrosion (IGC) attack after DL-EPR was investigated by optical (OM) and scanning electron microscopy (SEM) and by focused ion beam (FIB) coupled to SEM. Thermal aging caused the precipitation of mainly chromium nitrides at grain boundaries. Aging at 650 °C or short aging times (5 min) at 750 °C caused nitride precipitation mainly at α/α grain boundaries as a result of fast diffusion of chromium in this phase. Aging at 850 °C or aging times from 10 to 60 min at 750 °C also allowed the precipitation at the α/γ interface. Nitrides at γ/γ grain boundaries were observed rarely and only after long aging times (60 min) at 850 °C. Electrochemical tests showed that in as-received samples, pitting attack only affected the α phase. Conversely, in aged samples, pitting and IGC attack were detected close to nitrides in correspondence of α/α and α/γ grain boundaries depending on aging temperatures and times.

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Characterization of Single Grain Boundaries in a Bi-Doped ZnO Varistor Using a Focused Ion Beam System

Japanese Journal of Applied Physics ◽

10.1143/jjap.39.4493 ◽

2000 ◽

Vol 39 (Part 1, No. 7B) ◽

pp. 4493-4496 ◽

Cited By ~ 5

Author(s):

Junji Tanimura ◽

Osamu Wada ◽

Hiroshi Kurokawa ◽

Naomi Furuse ◽

Masahiro Kobayashi

Keyword(s):

Grain Boundaries ◽

Focused Ion Beam ◽

Ion Beam ◽

Zno Varistor ◽

Beam System ◽

Single Grain ◽

Doped Zno

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Simulating the effect of grain boundaries on microstructurally small fatigue crack growth from a focused ion beam notch through a three-dimensional array of grains

Acta Materialia ◽

10.1016/j.actamat.2016.04.006 ◽

2016 ◽

Vol 112 ◽

pp. 20-39 ◽

Cited By ~ 28

Author(s):

William D. Musinski ◽

David L. McDowell

Keyword(s):

Fatigue Crack ◽

Fatigue Crack Growth ◽

Grain Boundaries ◽

Crack Growth ◽

Focused Ion Beam ◽

Ion Beam ◽

Three Dimensional ◽

Dimensional Array ◽

Small Fatigue Crack

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Interaction of cracks with precipitates and grain boundaries: Understanding crack growth mechanisms through focused ion beam tomography

Scripta Materialia ◽

10.1016/j.scriptamat.2006.12.025 ◽

2007 ◽

Vol 56 (8) ◽

pp. 697-700 ◽

Cited By ~ 60

Author(s):

C. Holzapfel ◽

W. Schäf ◽

M. Marx ◽

H. Vehoff ◽

F. Mücklich

Keyword(s):

Grain Boundaries ◽

Crack Growth ◽

Focused Ion Beam ◽

Ion Beam ◽

Growth Mechanisms ◽

Focused Ion Beam Tomography

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Implementing Transmission Electron Backscatter Diffraction for Atom Probe Tomography

Microscopy and Microanalysis ◽

10.1017/s1431927616011296 ◽

2016 ◽

Vol 22 (3) ◽

pp. 583-588 ◽

Cited By ~ 18

Author(s):

Katherine P. Rice ◽

Yimeng Chen ◽

Ty J. Prosa ◽

David J. Larson

Keyword(s):

Grain Boundary ◽

Grain Boundaries ◽

Atom Probe Tomography ◽

Focused Ion Beam ◽

Electron Backscatter Diffraction ◽

Ion Beam ◽

Atom Probe ◽

Specimen Preparation ◽

Inconel 600 ◽

Transmission Electron

AbstractThere are advantages to performing transmission electron backscattering diffraction (tEBSD) in conjunction with focused ion beam-based specimen preparation for atom probe tomography (APT). Although tEBSD allows users to identify the position and character of grain boundaries, which can then be combined with APT to provide full chemical and orientation characterization of grain boundaries, tEBSD can also provide imaging information that improves the APT specimen preparation process by insuring proper placement of the targeted grain boundary within an APT specimen. In this report we discuss sample tilt angles, ion beam milling energies, and other considerations to optimize Kikuchi diffraction pattern quality for the APT specimen geometry. Coordinated specimen preparation and analysis of a grain boundary in a Ni-based Inconel 600 alloy is used to illustrate the approach revealing a 50° misorientation and trace element segregation to the grain boundary.

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The Role of Zr in the High-Temperature Oxidation of Fe3Al

Materials Science Forum ◽

10.4028/www.scientific.net/msf.595-598.1103 ◽

2008 ◽

Vol 595-598 ◽

pp. 1103-1110 ◽

Cited By ~ 1

Author(s):

Kazimierz Przybylski ◽

Sébastien Chevalier ◽

P. Juzoń ◽

Alain Galerie ◽

Günter Borchardt ◽

...

Keyword(s):

High Temperature ◽

Grain Boundaries ◽

High Temperature Oxidation ◽

Focused Ion Beam ◽

Ion Beam ◽

Oxidation Mechanism ◽

Analytical Techniques ◽

Alumina Layer ◽

Temperature Oxidation

The paper describes an examination of the effect of the addition of zirconium as a third element on the heat-resisting properties and explains the high temperature oxidation mechanism of Fe3Al intermetallic compounds. The Fe3Al and Fe3Al-0,05Zr specimens have been isothermally oxidized in the temperature range of 1173-1473 K in synthetic air for 100 hrs. The formed oxide layer, about 1,5-2 μm thick, was Al2O3. An examination of the cross-sectioned scales by SEM-EDS showed that the alumina layer consisted of a small inner columnar layer and an outer equiaxed grain layer. Additionally, very fine (50-150 nm) oxide grains rich in Zr, further identified as ZrO2, were found across the alumina scales. To understand the role of Zr on the growth mechanism of α–Al2O3 oxide scale on Fe3Al materials, two-stage oxidation experiments were performed (16O2/18O2), followed by SIMS and TEM-SAD observations. Particular attention was paid to the use of TEM in order to precisely characterize the products on samples prepared using the FIB (Focused Ion Beam) method. A combination of analytical techniques revealed that ZrO2 particles, most of which were formed along alumina grain boundaries, enhanced oxygen diffusion along grain boundaries due to oxygen-deficient composition of zirconium oxide (ZrO2-y).

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The brittle fracture of polycrystalline zinc

Proceedings of The Royal Society A Mathematical Physical and Engineering Sciences ◽

10.1098/rspa.2007.1866 ◽

2007 ◽

Vol 463 (2085) ◽

pp. 2129-2151 ◽

Cited By ~ 24

Author(s):

G.M Hughes ◽

G.E Smith ◽

P.E.J Flewitt ◽

A.G Crocker

Keyword(s):

Brittle Fracture ◽

Grain Boundaries ◽

Fracture Process ◽

Focused Ion Beam ◽

Ion Beam ◽

Three Dimensional ◽

Geometrical Model ◽

Polycrystalline Materials ◽

Fracture Mechanisms ◽

Polycrystalline Zinc

In polycrystalline materials, grain boundaries provide an important contribution to the resistance to the propagation of both brittle and ductile cracks. Initially, in this paper, a three-dimensional geometrical model of the brittle fracture of polycrystalline zinc is developed, assuming a single (0001) cleavage plane in each grain. The model predicts that about one-half of the fracture process of the material will be associated with accommodation effects at grain boundaries. In contrast, experimental work over a range of temperatures shows that at low temperatures very little grain boundary failure occurs. There are two reasons for this discrepancy. Firstly, cleavage occurs on (0001) and also on the three variants of the {10-10} planes and secondly, deformation twinning plays a major role in the fracture process. The characteristics of these phenomena have been investigated in detail using focused ion beam microscopy, including subsurface examinations and metallographic techniques. The models were then extended to incorporate these additional mechanisms. Comparisons between the predictions and the experimental observations are discussed and enable information to be deduced about the relative energies of the different fracture mechanisms.

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Redistribution of Alloy Elements during Nickel Silicide Formation: Benefit of Atom Probe Tomography

Defect and Diffusion Forum ◽

10.4028/www.scientific.net/ddf.309-310.161 ◽

2011 ◽

Vol 309-310 ◽

pp. 161-166 ◽

Cited By ~ 1

Author(s):

C. Perrin ◽

K. Hoummada ◽

I. Blum ◽

A. Portavoce ◽

M. Descoins ◽

...

Keyword(s):

Grain Boundaries ◽

Atom Probe Tomography ◽

Focused Ion Beam ◽

Ion Beam ◽

Laser Pulses ◽

Atom Probe ◽

Alloy Element ◽

Nickel Silicide ◽

Three Dimensions ◽

Nanometer Scale

The unique capabilities of atom probe tomography (APT) to characterize internal interfaces and layer chemistry with sub-nanometer scale resolution in three dimensions have been recently opened up to materials with poor electrical conductivity by the use of ultrafast laser pulses. The progress in sample preparation (focused ion beam) as well as in instrument performance enable now the analysis of relatively large volumes with typical diameters of 100 to 200 nm and depths of several hundred nm (this corresponds to an increase by several order of magnitude compared to the former instrument) of site specific samples. In this work, APT is used to study the effects of Pt on the formation and stability of Ni silicides. The precise location of this alloy element has been determined at the nanometer scale: In particular, APT allows us to quantify the amount of Pt in the grain boundaries (GB) of Ni2Si for about 100 different grain boundaries and thus to better characterize the GB diffusion and segregation.

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An Investigation into Fracture of Multi-Crystalline Silicon

Solid State Phenomena ◽

10.4028/www.scientific.net/ssp.156-158.55 ◽

2009 ◽

Vol 156-158 ◽

pp. 55-60

Author(s):

B.R. Mansfield ◽

David E.J. Armstrong ◽

Peter R. Wilshaw ◽

John D. Murphy

Keyword(s):

Grain Boundaries ◽

Focused Ion Beam ◽

Crystalline Silicon ◽

Ion Beam ◽

Single Crystal Silicon ◽

Front Surface ◽

Beam Width ◽

Relative Strength ◽

Transgranular Fracture ◽

Crystal Silicon

As the thickness of multi-crystalline silicon solar cells continues to reduce, understanding the mechanical properties of the material is of increasing importance. In this study, a variety of techniques are used to study multi-crystalline silicon. Fracture tests are performed using four- and three-point bending. The fracture stress of as-sawn material reduces with increasing beam width and is increased in beams with a polished front surface. This indicates that fracture initiates from surface flaws. Modifications to standard fracture testing, including testing under liquid, are made so that beams fracture into just two pieces. By determining the crystallography either side of the location of fracture, multi-crystalline silicon was found to fail by transgranular fracture in the samples studied. Further evidence for this is gained from indentation experiments at grain boundaries. In order to understand the relative strength of grain boundaries, new approaches need to be considered. Therefore, a novel micromechanical technique, which enables individual grain boundaries to be studied, has started to be applied to multi-crystalline silicon. A focused ion beam is used to mill micron-scale cantilevers across notched grain boundaries, which are then loaded to fracture using the tip of a nanoindenter. The technique is shown to reproduce the known fracture toughness of {110} planes in single-crystal silicon, giving a value of 0.7 ± 0.3MPam1/2. Preliminary results are presented for fracture of multi-crystalline silicon.

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Analysis of polycrystalline microstructure of AlMgSc alloy observed by 3D EBSD

Image Analysis & Stereology ◽

10.5566/ias.2224 ◽

2020 ◽

Author(s):

Jaromír Kopeček ◽

Jakub Staněk ◽

Stanislav Habr ◽

Filip Seitl ◽

Lukas Petrich ◽

...

Keyword(s):

Spatial Distribution ◽

Grain Boundaries ◽

Focused Ion Beam ◽

Ion Beam ◽

Three Dimensional ◽

Morphological Characteristics ◽

Polycrystalline Materials ◽

Electron Backscattered Diffraction ◽

Data Set ◽

3D Data

The aim of this paper is to evaluate an ambitious imaging experiment and to contribute to the methodology of statistical inference of the three-dimensional microstructure of polycrystalline materials. The microstructure of the considered Al-3Mg-0.2Sc alloy was investigated by three-dimensional electron backscattered diffraction (3D-EBSD), i.e., tomographic imaging with xenon plasma focused ion beam (Xe-FIB) alongside EBSD. The samples were subjected to severe plastic deformations by equal channel angular dressing (ECAP) and annealed subsequently prior to the mapping. First we compared the misorientation level needed for a reliable segmentation of grains distinguishing between conventional evaluation of two-dimensional cuts and the 3D data set. Then, using methods of descriptive spatial statistics, various morphological characteristics of a large number of grains were analyzed, as well as the crystallographic texture and the spatial distribution of grain boundaries. According to the results stated so far in the literature, an even microstructure was expected, nevertheless local inhomogeneities in grains and grain boundaries with regard to their size, texture and spatial distribution were observed and justified.

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