scholarly journals Precision Thermal Treatments, Atom Probe Characterization, and Modeling to Describe the Fe-Cr Metastable Miscibility Gap

2021 ◽  
Vol 52 (4) ◽  
pp. 1453-1464
Author(s):  
Alexander Dahlström ◽  
Frederic Danoix ◽  
Peter Hedström ◽  
Joakim Odqvist ◽  
Malin Selleby ◽  
...  
Keyword(s):  
High Precision ◽  
Thermodynamic Modeling ◽  
Experimental Work ◽  
Atom Probe Tomography ◽  
Atom Probe ◽  
Miscibility Gap ◽  
Thermal Treatments ◽  
Micro Hardness ◽  
Consolute Temperature ◽  
Vickers Micro Hardness

Abstract The Fe-Cr metastable miscibility gap has been studied by high-precision thermal treatments, Vickers micro-hardness (HV) measurements, and atom probe tomography (APT). Thermodynamic modeling further supplements the experimental work. The results obtained show that recent thermodynamic descriptions of the metastable miscibility gap found in literature generally overestimates the consolute temperature. We can show that the source of ambiguity in previous studies is most likely a lack of clear distinction between Cr-Cr clustering and $$ \alpha^{\prime} $$ α ′ formation. This distinction is here made by APT results, and it leads to a determined consolute temperature of 580 ± 1 °C for Fe0.50Cr0.50. The revised thermodynamic modeling of the metastable miscibility gap captures the experimental results and is consistent with the overall picture from the Fe-Cr data in the literature. Graphic Abstract

scholarly journals A Reassessment of the Metastable Miscibility Gap in Al-Ag Alloys by Atom Probe Tomography

2007 ◽  
Vol 13 (6) ◽  
pp. 484-492 ◽  
Author(s):  
Emmanuelle A. Marquis
Keyword(s):  
Atom Probe Tomography ◽  
Temporal Evolution ◽  
Atom Probe ◽  
Time Dependent ◽  
Miscibility Gap ◽  
Preliminary Results

The evolution of Guinier-Preston zones in an Al-2.7 at.% Ag alloy was studied using atom probe tomography. The composition and morphology of the GP zones are time dependent, explaining discrepancies in previous work. This result requires the metastable miscibility gap for GP zones to be reevaluated, highlighting the importance of the temporal evolution of the GP zones. Preliminary results on the composition of γ′ and γ plates are also presented.

scholarly journals Probing the Miscibility Gap of the Pt–Pd Binary System by Atom Probe Tomography

2021 ◽  
pp. 1-11
Author(s):  
Yoonhee Lee ◽  
Patrick Stender ◽  
Sebastian Manuel Eich ◽  
Guido Schmitz
Keyword(s):  
Diffusion Coefficients ◽  
Atom Probe Tomography ◽  
Series Solution ◽  
Isothermal Annealing ◽  
Ion Beam ◽  
Atom Probe ◽  
Miscibility Gap ◽  
Ion Beam Sputtering ◽  
Diffusion Controlled ◽  
Beam Sputtering

To solve the uncertainty of the platinum (Pt)–palladium (Pd) phase diagram, especially the existence of a suggested miscibility gap, atom probe tomography (APT) was used to determine the time evolution of the composition after heat treatment. Due to the extraordinarily slow diffusion in the temperature range of the controversial phase separation, the investigated volume was limited to nano-sized multiple layers deposited by ion beam sputtering (IBS). The evaporated volume was reconstructed from the obtained datasets and the respective diffusion coefficients were determined using the Fourier series solution of the diffusion equation. Beginning with pure Pt and Pd layers annealed at 673, 773, 873, and 973 K, the mixing appears to be purely diffusion controlled in the chosen annealing times, but the state of complete mixing was still not observed. Therefore, extended isothermal annealing sequences at 673 and 773 K with pre-alloyed layers have been carried out. They clearly suggest complete mixing even at the lowest investigated temperatures.

A Comparison of Tem and Apfim to the Interpretation of Modulated Microstructures

1985 ◽  
Vol 43 ◽  
pp. 70-71
Author(s):  
M.G. Burke ◽  
M.K. Miller
Keyword(s):  
Low Temperature ◽  
Microstructural Characterization ◽  
Superlattice Reflection ◽  
High Volume ◽  
Atom Probe ◽  
Dark Field ◽  
Miscibility Gap ◽  
Second Phase ◽  
Two Phase ◽  
Probe Field

Interpretation of fine-scale microstructures containing high volume fractions of second phase is complex. In particular, microstructures developed through decomposition within low temperature miscibility gaps may be extremely fine. This paper compares the morphological interpretations of such complex microstructures by the high-resolution techniques of TEM and atom probe field-ion microscopy (APFIM).The Fe-25 at% Be alloy selected for this study was aged within the low temperature miscibility gap to form a <100> aligned two-phase microstructure. This triaxially modulated microstructure is composed of an Fe-rich ferrite phase and a B2-ordered Be-enriched phase. The microstructural characterization through conventional bright-field TEM is inadequate because of the many contributions to image contrast. The ordering reaction which accompanies spinodal decomposition in this alloy permits simplification of the image by the use of the centered dark field technique to image just one phase. A CDF image formed with a B2 superlattice reflection is shown in fig. 1. In this CDF micrograph, the the B2-ordered Be-enriched phase appears as bright regions in the darkly-imaging ferrite. By examining the specimen in a [001] orientation, the <100> nature of the modulations is evident.

Evaluation of the Resistance of Individual Si Die to Cracking

1998 ◽  
Author(s):  
R. Berriche ◽  
R.K. Lowry ◽  
M.I. Rosenfield
Keyword(s):  
Thermal Cycling ◽  
Hardness Test ◽  
Mechanical Stresses ◽  
Test Method ◽  
Processing Conditions ◽  
Micro Hardness ◽  
Test Methodology ◽  
Vickers Micro Hardness

Abstract The present work investigated the use of the Vickers micro-hardness test method to determine the resistance of individual die to cracking. The results are used as an indicator of resistance to failure under the thermal and mechanical stresses of packaging and subsequent thermal cycling. Indentation measurements on die back surfaces are used to determine how changes in wafer backside processing conditions affect cracks that form around impressions produced at different loads. Test methodology and results obtained at different processing conditions are discussed.

scholarly journals Correlating nanoscale secondary ion mass spectrometry and atom probe tomography analysis of uranium enrichment in metallic nuclear fuel

The Analyst ◽  
2021 ◽  
Vol 146 (1) ◽  
pp. 69-74
Author(s):  
Elizabeth Kautz ◽  
John Cliff ◽  
Timothy Lach ◽  
Dallas Reilly ◽  
Arun Devaraj
Keyword(s):  
Mass Spectrometry ◽  
Nuclear Fuel ◽  
Atom Probe Tomography ◽  
Secondary Ion Mass Spectrometry ◽  
Atom Probe ◽  
Uranium Enrichment ◽  
Length Scales ◽  
Atom Probe Tomography Analysis ◽  
Secondary Ion ◽  
Tomography Analysis

235U enrichment in a metallic nuclear fuel was measured via NanoSIMS and APT, allowing for a direct comparison of enrichment across length scales and resolutions.

scholarly journals Inside Front Cover: Atom Probe Tomography of Encapsulated Hydroxyapatite Nanoparticles (Small Methods 2/2021)

Small Methods ◽  
2021 ◽  
Vol 5 (2) ◽  
pp. 2170004
Author(s):  
Daniel S. Mosiman ◽  
Yi‐Sheng Chen ◽  
Limei Yang ◽  
Brian Hawkett ◽  
Simon P. Ringer ◽  
...  
Keyword(s):  
Atom Probe Tomography ◽  
Atom Probe ◽  
Hydroxyapatite Nanoparticles ◽  
Front Cover

scholarly journals The distribution of O and N in the surface region of laser-patterned titanium revealed by atom probe tomography

2021 ◽  
pp. 150193
Author(s):  
D. Kuczyńska-Zemła ◽  
G. Sundell ◽  
M. Zemła ◽  
M. Andersson ◽  
H. Garbacz
Keyword(s):  
Atom Probe Tomography ◽  
Surface Region ◽  
Atom Probe

scholarly journals 3D sub-nanometer analysis of glucose in an aqueous solution by cryo-atom probe tomography

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
T. M. Schwarz ◽  
C. A. Dietrich ◽  
J. Ott ◽  
E. M. Weikum ◽  
R. Lawitzki ◽  
...  
Keyword(s):  
Atom Probe Tomography ◽  
Density Functional ◽  
Chemical Characterization ◽  
Analytical Techniques ◽  
Atom Probe ◽  
Characterization Methods ◽  
Signal Deconvolution ◽  
The Stability ◽  
Frozen Solutions ◽  
3D Volume

AbstractAtom Probe Tomography (APT) is currently a well-established technique to analyse the composition of solid materials including metals, semiconductors and ceramics with up to near-atomic resolution. Using an aqueous glucose solution, we now extended the technique to frozen solutions. While the mass signals of the common glucose fragments CxHy and CxOyHz overlap with (H2O)nH from water, we achieved stoichiometrically correct values via signal deconvolution. Density functional theory (DFT) calculations were performed to investigate the stability of the detected pyranose fragments. This paper demonstrates APT’s capabilities to achieve sub-nanometre resolution in tracing whole glucose molecules in a frozen solution by using cryogenic workflows. We use a solution of defined concentration to investigate the chemical resolution capabilities as a step toward the measurement of biological molecules. Due to the evaporation of nearly intact glucose molecules, their position within the measured 3D volume of the solution can be determined with sub-nanometre resolution. Our analyses take analytical techniques to a new level, since chemical characterization methods for cryogenically-frozen solutions or biological materials are limited.

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