Automated EBSD or Orientation Imaging Microscopy (OIM) systems are being used in combination with other equipment within the scanning electron microscope (SEM) to perform in-situ measurements. This paper briefly revie...Automated EBSD or Orientation Imaging Microscopy (OIM) systems are being used in combination with other equipment within the scanning electron microscope (SEM) to perform in-situ measurements. This paper briefly reviews OIM studies of in-situ experiments performed using tensile and heating stages as well as in-situ serial sectioning. In particular, in-situ OIM scan results on an aluminum alloy sample deformed in tension; phase transformations in a cobalt sample, recrystallization and grain growth in a copper sample and serial sectioning of a nickel super-alloy sample are reviewed.展开更多
In this study, factors affecting the crystal structure of flame-synthesized Y2O3 ：Eu particles were investigated, especially the particle size effect and its interaction with Eu doping concentration, Polydisperse Y2O...In this study, factors affecting the crystal structure of flame-synthesized Y2O3 ：Eu particles were investigated, especially the particle size effect and its interaction with Eu doping concentration, Polydisperse Y2O3：Eu （size range 200 nm to 3μm） powder samples with Eu doping concentrations from 2,5 mol% to 25 mol% were generated in either H2/air or H2/O2 substrate-free flames. The crystal structure of the powder samples was determined by powder X-ray diffraction （XRD）, which was complemented by pho- toluminescence （PL） measurements. Single particle crystal structure was determined by single particle selected area electron diffraction （SAED）, and for the first time, by electron backscatter diffraction （EBSD）. H2/air flames resulted in cubic phase Y2O3：Eu particles with hollow morphology and irregular shapes, Particles from H2/O2 flames had dense and spherical morphology; samples with lower Eu doping concen- trations had mixed cubic/monoclinic phases; samples with the highest Eu doping concentrations were phase-pure monoclinic. For samples generated from H2/02 flames, a particle size effect and its interaction with Eu doping concentration were found： particles smaller than a critical diameter had the monoclinic phase, and this critical diameter increased with increasing Eu doping concentration, These findings suggest that the formation of monoclinic Y2O3：Eu is inevitable when extremely hot substrate-free flames are used, because typical flame-synthesized Y203 ：Eu particle sizes are well below the critical diameter, However, it may be possible to generate particles with dense, spherical morphology and the desired cubic structure by using a moderately high flame temperature that enables fast sintering without melting the particles.展开更多
Electron Backscatter Diffraction(EBSD) has been used in conjunction with a Scanning Electron Microscope(SEM) combined with a focused ion beam(FIB) instrument to obtain three dimensional(3D) high resolution characteriz...Electron Backscatter Diffraction(EBSD) has been used in conjunction with a Scanning Electron Microscope(SEM) combined with a focused ion beam(FIB) instrument to obtain three dimensional(3D) high resolution characterizations of crystalline microstructures.This work reports on continued development that has proceeded on this technique.The technique is based on automated in-situ serial sectioning using the FIB and characterization of the sections using automated EBSD or orientation imaging microscopy(OIM).The technique extends the powerful features of two dimensional OIM into the third spatial dimension.This allows additional descriptive microstructural parameters to be obtained,for example the morphology and the crystallographic indices of interface planes.This paper provides an overview of the technique and shows results from two different samples: pearlite colonies in a high carbon steel and twin related grain triplets in a NiCo thin film.展开更多
基金The authors acknowledge the contribution of Seiichi Suzuki of TSL Japan for the engineering of the heating stage Robert Kubic and Raja Mishra of General Motors for providing access to the in-situ tensile stage+1 种基金 Michael Uchic and co-workers at the Air Force Research Laboratory for collecting and sharing the threedimensional data and Tom Lillo of Iaho National Engineering and Environmental Laboratory for providing the copper ECAE sample.
文摘Automated EBSD or Orientation Imaging Microscopy (OIM) systems are being used in combination with other equipment within the scanning electron microscope (SEM) to perform in-situ measurements. This paper briefly reviews OIM studies of in-situ experiments performed using tensile and heating stages as well as in-situ serial sectioning. In particular, in-situ OIM scan results on an aluminum alloy sample deformed in tension; phase transformations in a cobalt sample, recrystallization and grain growth in a copper sample and serial sectioning of a nickel super-alloy sample are reviewed.
基金Financial support for this work was provided by Texas A&M University and Texas Engineering Experiment Station
文摘In this study, factors affecting the crystal structure of flame-synthesized Y2O3 ：Eu particles were investigated, especially the particle size effect and its interaction with Eu doping concentration, Polydisperse Y2O3：Eu （size range 200 nm to 3μm） powder samples with Eu doping concentrations from 2,5 mol% to 25 mol% were generated in either H2/air or H2/O2 substrate-free flames. The crystal structure of the powder samples was determined by powder X-ray diffraction （XRD）, which was complemented by pho- toluminescence （PL） measurements. Single particle crystal structure was determined by single particle selected area electron diffraction （SAED）, and for the first time, by electron backscatter diffraction （EBSD）. H2/air flames resulted in cubic phase Y2O3：Eu particles with hollow morphology and irregular shapes, Particles from H2/O2 flames had dense and spherical morphology; samples with lower Eu doping concen- trations had mixed cubic/monoclinic phases; samples with the highest Eu doping concentrations were phase-pure monoclinic. For samples generated from H2/02 flames, a particle size effect and its interaction with Eu doping concentration were found： particles smaller than a critical diameter had the monoclinic phase, and this critical diameter increased with increasing Eu doping concentration, These findings suggest that the formation of monoclinic Y2O3：Eu is inevitable when extremely hot substrate-free flames are used, because typical flame-synthesized Y203 ：Eu particle sizes are well below the critical diameter, However, it may be possible to generate particles with dense, spherical morphology and the desired cubic structure by using a moderately high flame temperature that enables fast sintering without melting the particles.
文摘Electron Backscatter Diffraction(EBSD) has been used in conjunction with a Scanning Electron Microscope(SEM) combined with a focused ion beam(FIB) instrument to obtain three dimensional(3D) high resolution characterizations of crystalline microstructures.This work reports on continued development that has proceeded on this technique.The technique is based on automated in-situ serial sectioning using the FIB and characterization of the sections using automated EBSD or orientation imaging microscopy(OIM).The technique extends the powerful features of two dimensional OIM into the third spatial dimension.This allows additional descriptive microstructural parameters to be obtained,for example the morphology and the crystallographic indices of interface planes.This paper provides an overview of the technique and shows results from two different samples: pearlite colonies in a high carbon steel and twin related grain triplets in a NiCo thin film.
