scholarly journals The Role of Hydrogen in Hydrogen Embrittlement of Metals: The Case of Stainless Steel

Metals ◽  
2019 ◽  
Vol 9 (4) ◽  
pp. 406 ◽  
Author(s):  
Young Kim ◽  
Sung Kim ◽  
Byung Choe
Keyword(s):  
Stainless Steel ◽  
Hydrogen Embrittlement ◽  
Focused Ion Beam ◽  
Materials Science ◽  
Ion Beam ◽  
Tensile Tests ◽  
Lattice Contraction ◽  
Thin Foils ◽  
Before And After ◽  
Cold Worked

Hydrogen embrittlement (HE) of metals has remained a mystery in materials science for more than a century. To try to clarify this mystery, tensile tests were conducted at room temperature (RT) on a 316 stainless steel (SS) in air and hydrogen of 70 MPa. With an aim to directly observe the effect of hydrogen on ordering of 316 SS during deformation, electron diffraction patterns and images were obtained from thin foils made by a focused ion beam from the fracture surfaces of the tensile specimens. To prove lattice contraction by ordering, a 40% CW 316 SS specimen was thermally aged at 400 °C to incur ordering and its lattice contraction by ordering was determined using neutron diffraction by measuring its lattice parameters before and after aging. We demonstrate that atomic ordering is promoted by hydrogen, leading to formation of short-range order and a high number of planar dislocations in the 316 SS, and causing its anisotropic lattice contraction. Hence, hydrogen embrittlement of metals is controlled by hydrogen-enhanced ordering during RT deformation in hydrogen. Hydrogen-enhanced ordering will cause the ordered metals to be more resistant to HE than the disordered ones, which is evidenced by the previous observations where furnace-cooled metals with order are more resistant to HE than water-quenched or cold worked metals with disorder. This finding strongly supports our proposal that strain-induced martensite is a disordered phase.

Hydrogen Embrittlement of PH 13-8 Mo Stainless Steel—The Effect of Surface Condition

CORROSION ◽  
1984 ◽  
Vol 40 (4) ◽  
pp. 146-151 ◽  
Author(s):  
G. T. Murray ◽  
H. H. Honegger ◽  
T. Mousel
Keyword(s):  
Stainless Steel ◽  
Hydrogen Embrittlement ◽  
Precipitation Hardening ◽  
Surface Condition ◽  
Tensile Tests ◽  
Time To Failure ◽  
Hydrogen Charging ◽  
Charging Time ◽  
Cold Worked ◽  
Effect Of Surface

Abstract The susceptibility of precipitation hardening 13-8 Mo stainless steel to hydrogen embrittlement (HE) was measured by both post hydrogen charging tensile tests and by time to failure tests while being subjected to hydrogen charging and a static stress below the yield stress. In the former, it was found that the ductility was decreased substantially after only 30 min charging time. The strength was markedly reduced after 2 h charging time. In the delayed failure tests, it was found that a localized cold worked surface condition promoted crack formation.

Transmission Electron Microscope Specimen Preparation of Metal Matrix Composites Using the Focused Ion Beam Miller

1999 ◽  
Vol 5 (S2) ◽  
pp. 892-893
Author(s):  
J.M. Cairney ◽  
R.D. Smith ◽  
P.R. Munroe
Keyword(s):  
Metal Matrix Composites ◽  
Metal Matrix ◽  
Focused Ion Beam ◽  
Materials Science ◽  
Volume Fraction ◽  
Ion Beam ◽  
Semiconductor Industry ◽  
Specimen Preparation ◽  
Matrix Composites ◽  
Thin Foils

The focused ion beam (FIB) miller has been widely accepted as a powerful tool in the semiconductor industry. However, it is now finding applications in more general materials science applications. The high resolution, energetic gallium ion beam can rapidly and precisely section materials to reveal their internal structure; one particularly valuable application being the preparation of thin foils for TEM examination, especially from heterogenous materials.To date, TEM sample preparation using FIBs has concentrated on semiconductor cross-sections [1], powders [2], and surface treated materials, e.g. galvanized steels [3]. However, thin foils of grossly heterogeneous materials, such as metal-matrix composites, are also difficult to prepare using conventional methods and are therefore well suited to sectioning using the FIB. In this study, thin foils were prepared from two composite materials: a 7075 aluminium alloy containing a 20% volume fraction of SiC particles and a FeAl alloy containing a 60% volume fraction of WC particles.

Oxidation of Alloy-X in Subcritical, Transition, and Supercritical Water

CORROSION ◽  
10.5006/3881 ◽  
2021 ◽  
Author(s):  
Zachary Karmiol ◽  
Dev Chidambaram
Keyword(s):  
Supercritical Water ◽  
Photoelectron Spectroscopy ◽  
Focused Ion Beam ◽  
Elevated Temperatures ◽  
Subcritical Water ◽  
Ion Beam ◽  
X Ray Diffraction ◽  
X Ray ◽  
Nickel Based Superalloy ◽  
Before And After

This work investigates the oxidation of a nickel based superalloy, namely Alloy X, in water at elevated temperatures: subcritical water at 261°C and 27 MPa, the transition between subcritical and supercritical water at 374°C and 27 MPa, and supercritical water at 380°C and 27 MPa for 100 hours. The morphology of the sample surfaces were studied using scanning electron microscopy coupled with focused ion beam milling, and the surface chemistry was investigated using X-ray diffraction, Raman spectroscopy, energy dispersive X-ray spectroscopy, and X-ray photoelectron spectroscopy before and after exposure studies. Surfaces of all samples were identified to comprise of a ferrite spinel containing aluminum.

FIB Techniques for Analysis of Metallurgical Specimens

2000 ◽  
Vol 6 (S2) ◽  
pp. 524-525 ◽  
Author(s):  
Michael W. Phaneuf ◽  
Jian Li
Keyword(s):  
Focused Ion Beam ◽  
Materials Science ◽  
Ion Beam ◽  
Semiconductor Industry ◽  
Zirconium Alloys ◽  
Chemical Information ◽  
Specimen Preparation ◽  
Orientation Contrast ◽  
Imaging Tool ◽  
Zinc Coatings

Focused ion beam (FIB) microscopes, the use of which is well established in the semiconductor industry, are rapidly gaining attention in the field of materials science, both as a tool for producing site specific, parallel sided TEM specimens and as a stand alone specimen preparation and imaging tool.Both FIB secondary ion images (FIB SII) and FIB secondary electron images (FIB SEI) contain novel crystallographic and chemical information. The ability to see “orientation contrast” in FIB SEI and to a lesser extent SII is well known for cubic materials and more recently stress-free FIB sectioning combined with FIB imaging have been shown to reveal evidence of plastic deformation in metallic specimens. Particularly in hexagonal metals, FIB orientation contrast is sometimes reduced or eliminated by the FIB sectioning process. We have successfully employed FIB gas assisted etching during FIB sectioning using XeF2 for zirconium alloys and Cl2 for zinc coatings on steels to retain orientation contrast during subsequent imaging.

Investigation of Ga ion implantation-induced damage in single-crystal 6H-SiC

2018 ◽  
Vol 1 (2) ◽  
pp. 115-123 ◽  
Author(s):  
Zhongdu He ◽  
Zongwei Xu ◽  
Mathias Rommel ◽  
Boteng Yao ◽  
Tao Liu ◽  
...  
Keyword(s):  
Ion Implantation ◽  
Single Crystal ◽  
Focused Ion Beam ◽  
Electron Backscatter Diffraction ◽  
Ion Beam ◽  
Implantation Dose ◽  
Formation Mechanisms ◽  
Schematic Model ◽  
Dose Threshold ◽  
Before And After

In order to investigate the damage in single-crystal 6H-silicon carbide (SiC) in dependence on ion implantation dose, ion implantation experiments were performed using the focused ion beam technique. Raman spectroscopy and electron backscatter diffraction were used to characterize the 6H-SiC sample before and after ion implantation. Monte Carlo simulations were applied to verify the characterization results. Surface morphology of the implantation area was characterized by the scanning electron microscope (SEM) and atomic force microscope (AFM). The ‘swelling effect’ induced by the low-dose ion implantation of 1014−1015 ions cm−2 was investigated by AFM. The typical Raman bands of single-crystal 6H-SiC were analysed before and after implantation. The study revealed that the thickness of the amorphous damage layer was increased and then became saturated with increasing ion implantation dose. The critical dose threshold (2.81 × 1014−3.26 × 1014 ions cm−2) and saturated dose threshold (˜5.31 × 1016 ions cm−2) for amorphization were determined. Damage formation mechanisms were discussed, and a schematic model was proposed to explain the damage formation.

Residual Stress of Focused Ion Beam-Exposed Polycrystalline Silicon

2006 ◽  
Vol 983 ◽  
Author(s):  
Kim M. Archuleta ◽  
David P. Adams ◽  
Michael J. Vasile ◽  
Julia E. Fulghum
Keyword(s):  
Residual Stress ◽  
Plane Stress ◽  
White Light ◽  
Polycrystalline Silicon ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Medium Energy ◽  
White Light Interferometry ◽  
Before And After ◽  
Beam Damage

AbstractMedium energy (30 keV) focused gallium ion beam exposure of silicon results in a compressive in-plane stress with a magnitude as large as 0.4 GPa. Experiments involve uniform irradiation of thin polysilicon microcantilevers (200 micron length) over a range of dose from 1 x 1016 to 2 x 1018 ions/cm2. The radii of curvature of microcantilevers are measured using white light interferometry before and after each exposure. The residual stress is determined from these radii and other measured properties using Stoney's equation. The large residual stress is attributed to ion beam damage, microstructural changes and implantation.

High Resolution FIB as a General Materials Science Tool

1998 ◽  
Vol 4 (S2) ◽  
pp. 492-493 ◽  
Author(s):  
M.W. Phaneuf ◽  
J. Li ◽  
T. Malis
Keyword(s):  
Integrated Circuit ◽  
Focused Ion Beam ◽  
Materials Science ◽  
Ion Beam ◽  
General Purpose ◽  
Ion Source ◽  
Specimen Preparation ◽  
Ion Beam Sputtering ◽  
Imaging Characteristics ◽  
Beam Sputtering

Focused Ion Beam or FIB systems have been used in integrated circuit production for some time. The ability to combine rapid, precision focused ion beam sputtering or gas-assisted ion etching with focused ion beam deposition allows for rapid-prototyping of circuit modifications and failure analysis of defects even if they are buried deep within the chip's architecture. Inevitably, creative TEM researchers reasoned that a FIB could be used to produce site specific parallel-sided, electron transparent regions, thus bringing about the rather unique situation wherein the specimen preparation device often was worth as much as the TEM itself.More recently, FIB manufacturers have concentrated on improving the resolution and imaging characteristics of these instruments, resulting in a more general-purpose characterization tool. The Micrion 2500 FIB system used in this study is capable of 4 nm imaging resolution using either secondary electron or secondary ions, both generated by a 50 kV liquid metal gallium ion source.

scholarly journals Investigation on the Corrosion Behavior of Lean Duplex Stainless Steel 2404 after Aging within the 650–850 °C Temperature Range

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 529 ◽  
Author(s):  
Federica Zanotto ◽  
Vincenzo Grassi ◽  
Andrea Balbo ◽  
Fabrizio Zucchi ◽  
Cecilia Monticelli
Keyword(s):  
Stainless Steel ◽  
Grain Boundaries ◽  
Duplex Stainless Steel ◽  
Corrosion Behavior ◽  
Thermal Aging ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Localized Corrosion ◽  
Fast Diffusion ◽  
Lean Duplex Stainless Steel

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.

The Effect of Focused Ion Beam (Fib) Specimen Geometry on X-Ray Fluorescence During Energy Dispersive X-Ray Spectroscopy (EDS) Analysis in the Transmission Electron Microscope (TEM)

1998 ◽  
Vol 4 (S2) ◽  
pp. 856-857
Author(s):  
David M. Longo ◽  
James M. Howe ◽  
William C. Johnson
Keyword(s):  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Focused Ion Beam ◽  
Materials Science ◽  
Bulk Material ◽  
Ion Beam ◽  
Energy Dispersive ◽  
Specimen Preparation ◽  
X Ray ◽  
Transmission Electron

The focused ion beam (FIB) has become an indispensable tool for a variety of applications in materials science, including that of specimen preparation for the transmission electron microscope (TEM). Several FIB specimen preparation techniques have been developed, but some problems result when FIB specimens are analyzed in the TEM. One of these is X-ray fluorescence from bulk material surrounding the thin membrane in FIB-prepared samples. This paper reports on a new FIB specimen preparation method which was devised for the reduction of X-ray fluorescence during energy dispersive X-ray spectroscopy (EDS) in the TEM.Figure 1 shows three membrane geometries that were investigated in this study on a single-crystal Si substrate with a RF sputter-deposited 50 nm Ni film. Membrane 1 is the most commonly reported geometry in the literature, with an approximately 20 urn wide trench and a membrane having a single wedge with a 1.5° incline.

Effect of gallium focused ion beam milling on preparation of aluminium thin foils

2010 ◽  
Vol 240 (3) ◽  
pp. 227-238 ◽  
Author(s):  
K.A. UNOCIC ◽  
M.J. MILLS ◽  
G.S. DAEHN
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Thin Foils ◽  
Focused Ion Beam Milling
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