Solute cluster formation in austenitic and ferritic alloys under ion irradiation: a three-dimensional atom probe characterization

2004 ◽  
Vol 36 (56) ◽  
pp. 575-580 ◽  
Author(s):  
R. Krummeich ◽  
P. Pareige ◽  
J. P. Massoud ◽  
S. Jumel
2019 ◽  
Vol 92 (10) ◽  
Author(s):  
Matthew J. Lloyd ◽  
Robert G. Abernethy ◽  
David E. J. Armstrong ◽  
Paul A. J. Bagot ◽  
Michael P. Moody ◽  
...  

Abstract A viable fusion power station is reliant on the development of plasma facing materials that can withstand the combined effects of high temperature operation and high neutron doses. In this study we focus on W, the most promising candidate material. Re is the primary transmutation product and has been shown to induce embrittlement through cluster formation and precipitation below its predicted solubility limit in W. We investigate the mechanism behind this using a kinetic Monte Carlo model, implemented into Stochastic Parallel PARticle Kinetic Simulator (SPPARKS) code and parameterised with a pairwise energy model for both interstitial and vacancy type defects. By introducing point defect sinks into our simulation cell, we observe the formation of Re rich clusters which have a concentration similar to that observed in ion irradiation experiments. We also compliment our computational work with atom probe tomography (APT) of ion implanted, model W-Re alloys. The segregation of Re to grain boundaries is observed in both our APT and KMC simulations. Graphical abstract


MRS Bulletin ◽  
1994 ◽  
Vol 19 (7) ◽  
pp. 21-26 ◽  
Author(s):  
Didier Blavette ◽  
Alain Menand

The emergence of the field ion microscope, invented by E.W. Müller in 1951, allowed, for the first time, direct observation of metallic materials in real space on an atomic scale. Field ionization of rare gas atoms near the surface of the material allowed production of an atomic resolution image of the material; field evaporation of surface atoms allowed observation into the depth of the sample.Field ion microscopy (FIM) has produced numerous impressive results, one of them being three-dimensional reconstruction of defect cascades produced by heavy ion irradiation in metals. FIM techniques have also contributed in a spectacular way to the knowledge of the crystallographic structure of grain boundaries. Surface diffusion as well as surface reconstruction phenomena are applications where, again, FIM gave surprisingly detailed information. This overview of applications of FIM in materials science emphasizes recent work. Detailed information and descriptions of earlier work can be found elsewhere.During the development of FIM techniques, the basic shortcomings of the instrument for investigating metallic alloys were rapidly recognized. In Cu3Pd alloys, for instance, Cu atoms are darkly imaged and therefore appear as vacancies similar to Co atoms in PtCo and Pt3Co. It is thus impossible to distinguish vacancies from solute atoms. This clearly limited the quantitative use of FIM to study short-rangeorder in dilute alloys or to investigate long-range order (Figure 1). Similarly, in two-phase materials, precipitates often give rise to quite visible contrast. For instance, in nickel-based alloys, aluminum-enriched precipitates appear in bright contrast. It is therefore possible to find the size and also the number density of particles present in the material. However, FIM does not provide any composition data.


2011 ◽  
Vol 22 (1) ◽  
pp. 015015 ◽  
Author(s):  
S Azimi ◽  
M B H Breese ◽  
Z Y Dang ◽  
Y Yan ◽  
Y S Ow ◽  
...  

2009 ◽  
Vol 57 (15) ◽  
pp. 4463-4472 ◽  
Author(s):  
Y.M. Chen ◽  
T. Ohkubo ◽  
M. Ohta ◽  
Y. Yoshizawa ◽  
K. Hono

2021 ◽  
Vol 7 (1) ◽  
Author(s):  
Yue Li ◽  
Xuyang Zhou ◽  
Timoteo Colnaghi ◽  
Ye Wei ◽  
Andreas Marek ◽  
...  

AbstractNanoscale L12-type ordered structures are widely used in face-centered cubic (FCC) alloys to exploit their hardening capacity and thereby improve mechanical properties. These fine-scale particles are typically fully coherent with matrix with the same atomic configuration disregarding chemical species, which makes them challenging to be characterized. Spatial distribution maps (SDMs) are used to probe local order by interrogating the three-dimensional (3D) distribution of atoms within reconstructed atom probe tomography (APT) data. However, it is almost impossible to manually analyze the complete point cloud (>10 million) in search for the partial crystallographic information retained within the data. Here, we proposed an intelligent L12-ordered structure recognition method based on convolutional neural networks (CNNs). The SDMs of a simulated L12-ordered structure and the FCC matrix were firstly generated. These simulated images combined with a small amount of experimental data were used to train a CNN-based L12-ordered structure recognition model. Finally, the approach was successfully applied to reveal the 3D distribution of L12–type δ′–Al3(LiMg) nanoparticles with an average radius of 2.54 nm in a FCC Al-Li-Mg system. The minimum radius of detectable nanodomain is even down to 5 Å. The proposed CNN-APT method is promising to be extended to recognize other nanoscale ordered structures and even more-challenging short-range ordered phenomena in the near future.


2008 ◽  
Vol 24 (6) ◽  
pp. 641-650 ◽  
Author(s):  
A. J. Craven ◽  
M. MacKenzie ◽  
A. Cerezo ◽  
T. Godfrey ◽  
P. H. Clifton

2017 ◽  
Vol 23 (5) ◽  
pp. 916-925
Author(s):  
Pritesh Parikh ◽  
Corey Senowitz ◽  
Don Lyons ◽  
Isabelle Martin ◽  
Ty J. Prosa ◽  
...  

AbstractThe semiconductor industry has seen tremendous progress over the last few decades with continuous reduction in transistor size to improve device performance. Miniaturization of devices has led to changes in the dopants and dielectric layers incorporated. As the gradual shift from two-dimensional metal-oxide semiconductor field-effect transistor to three-dimensional (3D) field-effect transistors (finFETs) occurred, it has become imperative to understand compositional variability with nanoscale spatial resolution. Compositional changes can affect device performance primarily through fluctuations in threshold voltage and channel current density. Traditional techniques such as scanning electron microscope and focused ion beam no longer provide the required resolution to probe the physical structure and chemical composition of individual fins. Hence advanced multimodal characterization approaches are required to better understand electronic devices. Herein, we report the study of 14 nm commercial finFETs using atom probe tomography (APT) and scanning transmission electron microscopy–energy-dispersive X-ray spectroscopy (STEM-EDS). Complimentary compositional maps were obtained using both techniques with analysis of the gate dielectrics and silicon fin. APT additionally provided 3D information and allowed analysis of the distribution of low atomic number dopant elements (e.g., boron), which are elusive when using STEM-EDS.


2010 ◽  
Vol 8 ◽  
pp. 141-144 ◽  
Author(s):  
Y. Hanaoka ◽  
S. Mikami ◽  
N. Mayama ◽  
T. Iwata ◽  
Y. Kajiwara ◽  
...  

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