Fim/atom Probe Studies of B—doped and Alloyed Ni3Ai

1986 ◽  
Vol 81 ◽  
Author(s):  
D.D. Sieloff ◽  
S.S. Brenner ◽  
M.G. Burke

AbstractField—ion microscopy and atom probe microanalysis have been used to determine thestructure and chemistry of grain boundaries in ductile, recrystallized Ni3Al containing 0.23 at % B (500 wt.ppm). The results indicate that the boron concentration fluctuates along the boundary plane and that the boron enriched zone is wider than expected from equilibrium—type adsorption. It was also found that boron lowers the aluminum concentration of some of the boundary regions.

1988 ◽  
Vol 133 ◽  
Author(s):  
D. N. Sieloff ◽  
S. S. Brenner ◽  
Hua Ming-Jian

ABSTRACTGrain boundary regions in B-doped as well as B-free Ni3AI were studied by field-ion microscopy and atom probe microanalysis. In the ductile, recrystallized, Ni-rich alloys the segregation of boron was often accompanied by an enrichment of nickel. Such an enrichment was not observed at boundaries in B-free alloys. Boron was also observed to segregate to the boundaries in a 25.2A1 - IB alloy which was reported to contain boron clusters. Such clusters were not observed, instead a high concentration of boron pairs were found.


1992 ◽  
Vol 295 ◽  
Author(s):  
M. K. Miller ◽  
Raman Jayaram

AbstractThe near atomic spatial resolution of the atom probe field ion microscope permits the elemental characterization of internal interfaces, grain boundaries and surfaces to be performed in a wide variety of materials. Information such as the orientation relationship between grains, topology of the interface, and the coherency of small precipitates with the surrounding matrix may be obtained from field ion microscopy. Details of the solute segregation may be obtained at the plane of the interface and as a function of distance from the interface for all elements simultaneously from atom probe compositional analysis. The capabilities and limitations of the atom probe technique in the characterization of internal interfaces is illustrated with examples of grain boundaries and interphase interfaces in a wide range of materials including intermetallics, model alloys, and commercial steels.


1989 ◽  
Vol 50 (C8) ◽  
pp. C8-381-C8-385
Author(s):  
T. J. GODFREY ◽  
R. P. SETNA ◽  
G. D.W. SMITH

2017 ◽  
Vol 23 (2) ◽  
pp. 255-268 ◽  
Author(s):  
Michal Dagan ◽  
Baptiste Gault ◽  
George D. W. Smith ◽  
Paul A. J. Bagot ◽  
Michael P. Moody

AbstractAn automated procedure has been developed for the reconstruction of field ion microscopy (FIM) data that maintains its atomistic nature. FIM characterizes individual atoms on the specimen’s surface, evolving subject to field evaporation, in a series of two-dimensional (2D) images. Its unique spatial resolution enables direct imaging of crystal defects as small as single vacancies. To fully exploit FIM’s potential, automated analysis tools are required. The reconstruction algorithm developed here relies on minimal assumptions and is sensitive to atomic coordinates of all imaged atoms. It tracks the atoms across a sequence of images, allocating each to its respective crystallographic plane. The result is a highly accurate 3D lattice-resolved reconstruction. The procedure is applied to over 2000 tungsten atoms, including ion-implanted planes. The approach is further adapted to analyze carbides in a steel matrix, demonstrating its applicability to a range of materials. A vast amount of information is collected during the experiment that can underpin advanced analyses such as automated detection of “out of sequence” events, subangstrom surface displacements and defects effects on neighboring atoms. These analyses have the potential to reveal new insights into the field evaporation process and contribute to improving accuracy and scope of 3D FIM and atom probe characterization.


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