Atom probe study of grain boundary segregation in technically pure molybdenum

Babinsky, Katharina; Weidow, Jonathan; Knabl, W.; Lorich, A.; Leitner, Harald; Primig, Sophie

doi:10.1016/j.matchar.2013.11.001

Cited by 49 publications

(12 citation statements)

References 30 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…If TKD resolves no deformation structures, the tip can be further thinned down and the process repeated until a feature of interest appears. The advantages of using TKD in a FIB/SEM to simultaneously mill and image an APT tip were recently demonstrated (Babinsky et al, 2014 a , 2014 b ). A highlight is no exchange between microscopes and very quick switchover between the two techniques.…”

Section: Resultsmentioning

confidence: 99%

Laser-Assisted Atom Probe Tomography of Deformed Minerals: A Zircon Case Study

et al. 2017

View full text Add to dashboard Cite

The application of atom probe tomography to the study of minerals is a rapidly growing area. Picosecond-pulsed, ultraviolet laser (UV-355 nm) assisted atom probe tomography has been used to analyze trace element mobility within dislocations and low-angle boundaries in plastically deformed specimens of the nonconductive mineral zircon (ZrSiO4), a key material to date the earth's geological events. Here we discuss important experimental aspects inherent in the atom probe tomography investigation of this important mineral, providing insights into the challenges in atom probe tomography characterization of minerals as a whole. We studied the influence of atom probe tomography analysis parameters on features of the mass spectra, such as the thermal tail, as well as the overall data quality. Three zircon samples with different uranium and lead content were analyzed, and particular attention was paid to ion identification in the mass spectra and detection limits of the key trace elements, lead and uranium. We also discuss the correlative use of electron backscattered diffraction in a scanning electron microscope to map the deformation in the zircon grains, and the combined use of transmission Kikuchi diffraction and focused ion beam sample preparation to assist preparation of the final atom probe tip.

show abstract

Section: Resultsmentioning

confidence: 99%

Laser-Assisted Atom Probe Tomography of Deformed Minerals: A Zircon Case Study

et al. 2017

View full text Add to dashboard Cite

show abstract

“…It allowed some insight into the robustness of the study being performed. For additional information on the technically pure Mo, including composition and processing conditions the reader is directed to (Babinsky et al, 2014 b ; Primig et al, 2015).…”

Section: Methodsmentioning

confidence: 99%

Correlating Atom Probe Crystallographic Measurements with Transmission Kikuchi Diffraction Data

et al. 2017

View full text Add to dashboard Cite

Correlative microscopy approaches offer synergistic solutions to many research problems. One such combination, that has been studied in limited detail, is the use of atom probe tomography (APT) and transmission Kikuchi diffraction (TKD) on the same tip specimen. By combining these two powerful microscopy techniques, the microstructure of important engineering alloys can be studied in greater detail. For the first time, the accuracy of crystallographic measurements made using APT will be independently verified using TKD. Experimental data from two atom probe tips, one a nanocrystalline Al-0.5Ag alloy specimen collected on a straight flight-path atom probe and the other a high purity Mo specimen collected on a reflectron-fitted instrument, will be compared. We find that the average minimum misorientation angle, calculated from calibrated atom probe reconstructions with two different pole combinations, deviate 0.7° and 1.4°, respectively, from the TKD results. The type of atom probe and experimental conditions appear to have some impact on this accuracy and the reconstruction and measurement procedures are likely to contribute further to degradation in angular resolution. The challenges and implications of this correlative approach will also be discussed.

show abstract

“…[4][5][6][7][8][9] Nevertheless, recrystallization annealing of the as-deformed and stress-relieved condition of molybdenum leads to a significant increase of the DBTT and even more to intergranular embrittlement, which is believed to be caused by the larger grain size and segregation enrichments at the grain boundaries. [4][5][6][10][11][12][13] Recent atom probe investigations revealed phosphor, nitrogen and oxygen impurities at the grain boundaries of technically pure molybdenum 14,15 of which especially segregated oxygen is assumed to promote intergranular failure. 6,11,12 By adding small amounts of carbon and boron, the ductility of molybdenum can be improved.…”

Section: Introductionmentioning

confidence: 99%

Fracture Behavior and Delamination Toughening of Molybdenum in Charpy Impact Tests

Babinsky

Primig

Knabl

et al. 2016

JOM

Self Cite

View full text Add to dashboard Cite

This study combines advanced characterization techniques with conventional Charpy impact tests to relate the mechanical properties to the microstructure of technically pure molybdenum, especially regarding its toughness. V-notched samples with different orientations were prepared from a rolled molybdenum plate in stress-relieved and recrystallized condition. The ductile-tobrittle transition-temperature was analyzed in terms of the delamination behavior influenced by the microstructure. A pronounced increase of toughness was found for specific oriented samples, which can be explained by macroscopic delamination. Elongated grains led to enhanced delamination in Charpy impact tests with variations for different orientations. In general, delamination occurs as a result of brittle fracture; however, an increase in toughness in the Charpy impact test can be provoked. This mechanism is called thin sheet toughening or delamination toughening. Electron backscatter diffraction measurements were performed to get a deeper knowledge about crack propagation and delamination behavior in the rolled plate. Recrystallization shifts the transition region to significantly higher temperatures, which is explained by the globular grain shape as well as grain boundary segregation. The occurrence of delamination is discussed, taking texture, grain shape and segregation effects into account.

show abstract

Atom probe study of grain boundary segregation in technically pure molybdenum

Cited by 49 publications

References 30 publications

Laser-Assisted Atom Probe Tomography of Deformed Minerals: A Zircon Case Study

Laser-Assisted Atom Probe Tomography of Deformed Minerals: A Zircon Case Study

Correlating Atom Probe Crystallographic Measurements with Transmission Kikuchi Diffraction Data

Fracture Behavior and Delamination Toughening of Molybdenum in Charpy Impact Tests

Contact Info

Product

Resources

About