Investigation of γ/γ' Alloy by Simultaneous EDS and EBSP Analysis

1999 ◽  
Vol 5 (S2) ◽  
pp. 252-253
Author(s):  
J. A. Sutliff ◽  
S. D. Sitzman

This work describes an investigation of the microstructure of a γ/γ' Ni-base superalloy using the automated Electron BackScattering Pattern (EBSP) technique with simultaneous energy dispersive x-ray spectrometry (EDS). The goal of the investigation was to determine if EDS measurements necessary to discriminate γ' from γ' could be obtained when acquired simultaneously with a normal, high speed automated EBSP scan. The acquisition conditions that impact the EDS collection are: surface tilted ∼70 degrees from the beam axis, 70mm spectrometer to specimen distance limited by interference from the EBSP detector and approximately 300 ms available acquisition time.Thermo-mechanical processing of superalloys can produce coarse γ' that appears both within grains and at grain boundaries. In some conditions, the coarse γ' may be as large as many γ grains. As the crystal structure of γ and γ' are very similar, it is not possible to discriminate between the two phases using typical EBSP analysis. However, one needs to discriminate these phases in order to measure properties of the γ matrix such as texture and grain size.

Author(s):  
Marc H. Peeters ◽  
Max T. Otten

Over the past decades, the combination of energy-dispersive analysis of X-rays and scanning electron microscopy has proved to be a powerful tool for fast and reliable elemental characterization of a large variety of specimens. The technique has evolved rapidly from a purely qualitative characterization method to a reliable quantitative way of analysis. In the last 5 years, an increasing need for automation is observed, whereby energy-dispersive analysers control the beam and stage movement of the scanning electron microscope in order to collect digital X-ray images and perform unattended point analysis over multiple locations.The Philips High-speed Analysis of X-rays system (PHAX-Scan) makes use of the high performance dual-processor structure of the EDAX PV9900 analyser and the databus structure of the Philips series 500 scanning electron microscope to provide a highly automated, user-friendly and extremely fast microanalysis system. The software that runs on the hardware described above was specifically designed to provide the ultimate attainable speed on the system.


2007 ◽  
Vol 26-28 ◽  
pp. 243-246
Author(s):  
Xing Hua Yang ◽  
Jin Liang Huang ◽  
Xiao Wang ◽  
Chun Wei Cui

BaBi4-xLaxTi4O15 (BBLT) ceramics were prepared by conventional solid phase sintering ceramics processing technology. The crystal structure and the microstructure were detected by X-ray diffraction (XRD) and scanning electron microscope (SEM). The XRD analyses show that La3+ ions doping did not change the crystal structure of BBT ceramics. The sintering temperature increased from 1120°C to 1150°C with increasing Lanthanum content from 0 to 0.5, but it widened the sintering temperature range from 20°C to 50°C and refined the grain size of the BBT ceramic. Additionally, polarization treatment was performed and finally piezoelectric property was measured. As a result, the piezoelectric constant d33 of the 0.1at.% doped BBLT ceramics reached its highest value about 22pc/N at polarizing electric field of 8kV/mm and polarizing temperature of 120°C for 30min.


1986 ◽  
Vol 71 ◽  
Author(s):  
R. V. Joshi ◽  
D. A. Smith

AbstractThe characteristics of Selective LPCVD tungsten films produced by silicon reduction of tungsten hexafluoride are presented. The tungsten films deposited using Si(100), Si(111) and polysilicon undoped and doped substrates are analyzed by X-RAY, TEM, RBS, AES, SIMS and SEM. The as deposited bcc tungsten films are polycrystalline with a grain size 80 - 100Å. The effect of annealing temperature and time on the crystal structure of films was studied. Tungsten reacts to form tungsten silicide at 600°C. The silicide grain size is of the order of 100 - 200Å at 600°C and increases gradually to 400 - 500Å at 1000°C. The oxygen impurities in the film retard the silicide formation further at 1000°C. Silicon from the substrate out-diffuses to the film surface and reacts with the presence of oxygen impurities in the annealing ambient to form Si-O at 1000°C. As deposited film resistivities of 130-140 micro-ohm-cm are achieved reproducibly and reach 60-70 micro-ohm-cm after 1000°C annealing in nitrogen or argon ambient. The impurities H, C, O and F are found in the as deposited films.


Author(s):  
M. L. Fornasini ◽  
A. Saccone

AbstractThe crystal structures of two phases in the neodymium-gold system were determined by single crystal X-ray diffractometer methods,


1999 ◽  
Vol 77 (7) ◽  
pp. 515-520
Author(s):  
AAI Al-Bassam

Thin film polycrystalline solar cells based on CuIn1–xGaxSe2 have been fabricated and studied with x values from 0 to 1.0. The lattice parameters, grain size, and band gap were measured. Crystal structure and X-ray data of CuIn1–xGaxSe2 were determined using X-ray diffractometry. These materials had a cubic structure with x ≥ 0.5 and a tetragonal structure with x ≤ 0.5. The lattice constants vary linearly with composition. Grain size was measured using X-ray diffraction where the grain size increased linearly with Ga content. A grain size of 1.83-3.52 μm was observed with x ≤ 0.5, while it increased to 4.53 μm for x = 0.58.PACS No.: 70.73


2013 ◽  
Vol 747-748 ◽  
pp. 613-618
Author(s):  
Qiao Zhang ◽  
Shu Hua Liang ◽  
Chen Zhang ◽  
Jun Tao Zou

The as-cast Ni-W alloys with 15wt%W, 25wt%W and 30wt%W were annealed in hydrogen at 1100. The effect of the annealing time on the microstructure of Ni-W alloys was studied, and the phase constituents and microstructure of annealed Ni-W alloys were characterized by the X-ray diffraction (XRD) and scanning electron microscopy (SEM). The results showed that no any phase changed for Ni-15%W, Ni-25%W and Ni-30%W alloys annealed for 60 min, 90 min and 150 min, which were still consisted of single-phase Ni (W) solid solution. However, microstructure had a significant change after annealing. With increase of annealing time, the microstructure of Ni-15%W alloy became more uniform after annealing for 90 min, and the average grain size was 95μm, whereas the grain size of Ni-15%W alloy increased significantly after annealing for 150 min. For Ni-25%W and Ni-30%W, there was no obvious change on the grain size with increase of annealing time, and the amount of oxides at grain boundaries gradually reduced. After annealing for 150 min, the impurities at grain boundaries almost disappeared. Subsequently, the annealing at 1100 for 150 min was beneficial for the desired microstructure of Ni-25%W and Ni-30%W alloys.


2001 ◽  
Vol 672 ◽  
Author(s):  
Kathleen A. Dunn ◽  
Katharine Dovidenko ◽  
Anna W. Topol ◽  
Serge R. Oktyabrsky ◽  
Alain E. Kaloyeros

ABSTRACTZinc sulfide doped with manganese is extensively used for thin film electroluminescent device applications. In order to assess the key material and process challenges, ZnS:Mn layers were fabricated by metalorganic chemical vapor deposition in the 250°-500°C range on an AlTiO/InSnO/glass stack. The microstructure of the ZnS:Mn films was examined by Transmission Electron Microscopy (TEM) as part of a larger study which fully characterizes these films by a variety of structural and chemical characterization techniques, including Rutherford Backscattering, Secondary Ion Mass Spectroscopy, Atomic Force Microscopy, Scanning Electron Microscopy and X-ray Diffraction. For all the growth conditions, the films were found to be polycrystalline having predominantly 2H hexagonal ZnS structure. The ZnS grains are found to grow columnar as the film thickness increases, also widening in the direction parallel to the substrate surface and reaching the 100 - 200 nm average lateral size at the 650 nm film thickness. The presence of the 8H ZnS polytype was detected in the low-temperature ZnS:Mn films by TEM selected area electron diffraction and confirmed by X-ray diffraction analysis. Dark field TEM imaging correlated this 8H ring with very small (∼2.5 nm) grains present throughout the low temperature film with a slightly higher density at the film/substrate interface. The 700°C post-deposition annealing was found to initiate a solid state transformation to the cubic (3C) ZnS crystal structure, and resulted in an average grain size of ∼250 nm at the surface of the annealed film.


1995 ◽  
Vol 28 (5) ◽  
pp. 508-512 ◽  
Author(s):  
D.-M. Liu ◽  
L.-J. Lin ◽  
C.-J. Chen

Thermal expansion of (Sr1−x , K2x )Zr4(PO4)6 (SrKZP) (with x = 0–1) ceramic was investigated using both a dilatometer and a high-temperature X-ray diffractometer. The coefficients of thermal expansion (CTEs) of the SrKZP ceramic measured by the dilatometer demonstrate a similar trend as those from high-temperature X-ray diffraction. Both measurements show an ultra-low CTE at x = 0.5; nevertheless, this composition shows significant lattice thermal-expansion anisotropy (TEA), while the minimum TEA appears with composition x = 0.2. Although it possessed a sufficient degree of TEA, the x = 0.5 composition showed no visible microcracks or negligible microcracks over a grain size as large as 15 μm. A transition of space group from R{\bar 3} to R{\bar 3}c with composition between x = 0.3 and x = 0.5 has been observed. The crystal structure of the SrKZP ceramic with possible occupations of strontium and/or potassium within the lattice in relation to their influence on the CTEs is proposed.


1998 ◽  
Vol 4 (6) ◽  
pp. 567-575 ◽  
Author(s):  
David B. Williams

X-ray microanalysis of materials using energy-dispersive spectrometry (EDS) has made the greatest impact in studies of compositional changes at atomic-level interfaces. The small physical dimensions of the silicon detector make EDS the X-ray analyzer of choice for analytical transmission electron microscopy (AEM). X-ray analysis of thin foils in the AEM has contributed to our understanding of elemental segregation to interphase interfaces and grain boundaries, as well as other planar defects. Measurement of atomic diffusion on a small scale close to interphase interfaces has permitted determination of substitutional atomic diffusivities several orders of magnitude smaller than previously possible and has also led to the determination of low-temperature equilibrium phase diagrams through the measurement of local interface compositions. Elemental segregation to grain boundaries is responsible for such deleterious behavior as temper embrittlement, stress-corrosion cracking, and other forms of intergranular failure. On the other hand, segregation can bring about improvement in behavior: sintering aids in ceramics and de-embrittlement of intermetallics. EDS in the AEM has been responsible for quantitative analysis of all aspects of the segregation process and, more recently, in combination with electron energy-loss spectrometry (EELS) has given insight into why boundary segregation results in such significant macroscopic changes in properties.


2016 ◽  
Vol 17 (3) ◽  
pp. 346-349
Author(s):  
І.V. Semkiv

Energy dispersive x-ray spectroscopy of lowtemperature b¢-Ag8SnSe6 crystalcarried out. Energy dispersive spectrum shows only peaks related to Ag8SnSe6. Experimental optical absorption spectrum and band gap value 0.82 eV are determined. Theoretical calculation of absorption spectrum shows good agreement with experimental studies. Modeling of crystal structure of Ag8SnSe6 argyrodite and interatomic distances calculation are carried out.


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