Orientation Relationships and Constituent Phases

1999 ◽  
Vol 5 (S2) ◽  
pp. 264-265
Author(s):  
Jianian GUI ◽  
Xiaomei CHEN ◽  
Jing LIU ◽  
Jianbo WANG ◽  
Renhui WANG
Keyword(s):  
Basal Plane ◽  
Electron Backscatter Diffraction ◽  
Parent Phase ◽  
Microscopy Study ◽  
Structure Type ◽  
Electron Microscopy Study ◽  
Phase Identification ◽  
Orientation Relationships ◽  
Martensite Variant ◽  
Thin Foils

We report here our preliminary results on orientation determination and phase identification using the electron backscatter diffraction (EBSD) technique. Using a scanning electron microscope (SEM) equipped with the EBSD attachment. it is now possible to study the correspondence and orientation relationships of parent-phase and martensite variants in shape memory alloys (SMAs). Previously, such an information was obtained from large single crystals studied by micro-beam X-ray Laue diffraction and supplemented by transmission electron microscopy study of thin foils. Figs. 1(a), (b) and (c) are three EBSD patterns taken from neighboring areas in a Cu-12.55Al-4.86Ni (wt%) SMA. Computer simulation reveals that Fig. 1(a) belongs to the parent-phase of D03-structure type, and Figs. 1(b) and (c) belong to variants A and D of 2H martensite, respectively. Corresponding simulated EBSD patterns are shown in Figs. 1(d), (e) and (f). Fig. 1 indicates that the (0 0 2)A basal plane of the martensite variant A is transformed from the (-2-2 0)p plane of the parent-phase and its [0-1 0]A direction from the [0 0 1]P direction. The (0 0 2)D basal plane of the martensite variant D is transformed from the (2-2 0)P plane of the parent-phase and its [0 1 0 ]D direction from the [0 0 1]P direction.

In situtransmission electron microscopy study of the thermally induced formation of δ′-ZrO in pure Zr and Zr-based alloy

2017 ◽  
Vol 50 (4) ◽  
pp. 1028-1035 ◽  
Author(s):  
Hongbing Yu ◽  
Zhongwen Yao ◽  
Fei Long ◽  
Peyman Saidi ◽  
Mark R. Daymond
Keyword(s):  
Electron Microscopy ◽  
Thin Foil ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Orientation Relationships ◽  
Thermally Induced ◽  
Thin Foils ◽  
Orientation Relations ◽  
Transmission Electron

This study reportsin situobservations of the formation of the δ′-ZrO phase, occurring during the annealing of transmission electron microscopy (TEM) thin foils of both pure Zr and a Zr–Sn–Nb–Mo alloy at 973 K in a transmission electron microsope. The lattice parameters of δ′-ZrO were measured and determined to be similar to those of the ω-Zr phase. The orientation relationship between the δ′-ZrO and α-Zr phases has been identified as either {(11 \overline{2}0)}_{\rm ZrO}//{(0002)}_{\alpha} and {[0002]}_{\rm ZrO}//{[11 \overline{2}0]}_{\alpha} or {(\overline{1}011)}_{\rm ZrO}//{(0002)}_{\alpha} and {[01{\overline 1}1]_{{\rm{ZrO}}}}//{[11{\overline 2}0]_\alpha} depending on the orientation of the α grain relative to the TEM thin-foil normal. The nucleation and growth of δ′-ZrO were dynamically observed. This study suggests a new and convenient way to study oxidation mechanisms in Zr alloys and provides a deeper understanding of the properties of the newly reported δ′-ZrO. Since δ′-ZrO has a Zr sublattice which is identical to that of ω-Zr, the orientation relationships between the α and δ′-ZrO phases may also shed light on the orientation relations existing between α- and ω-Zr, and hence α- and ω-Ti.

Transmission Electron Microscopy Study of Mod Plzt and Pnzt Thin Films

1991 ◽  
Vol 243 ◽  
Author(s):  
Jhing–Fang Chang ◽  
Chi Kong Kwok ◽  
Seshu B. Desu
Keyword(s):  
Thin Films ◽  
Curie Temperature ◽  
Dopant Concentration ◽  
Microscopy Study ◽  
Lattice Parameter ◽  
Electron Microscopy Study ◽  
Bulk Materials ◽  
Thin Foils ◽  
Transmission Electron ◽  
Coating Method

AbstractBoth La and Nd–doped PZT, i.e., PLZT and PNZT, ferroelectric thin films were prepared by the metalorganic deposition (MOD) process. The precursor solutions used were derived from lead acetate, lanthanum acetylacetonate, neodymium acetate, zirconium n–propoxide, and titanium iso–propoxide. The dopant concentration of the films analyzed by electron microprobe indicated a one–to–one correspondence between film composition and the composition of the precursor from which the film was made. In this study, the effects of Nd and La dopants in PZT films on Curie temperature was determined by in–situ hot–stage TEM and compared with those of bulk materials. Lattice parameter and phase transformation were determined by both X–ray and electron diffraction. Our observations were: (1) Curie temperature decreases with increasing dopant concentration for both thin foils and bulk ceramics, (2) for a given dopant concentration, Curie temperature and crystal tetragonality of PNZT thin foils is lower than those of PLZT samples, (3) Curie temperature of thin foils was found to be less than those of the corresponding bulk materials, and (4) ferroelectric domains is easily observed in both PLZT and PNZT TEM specimens prepared by the spin–coating method.

scholarly journals Transmission Electron Microscopy Study of Microstructure and Crystallographic Orientation Relationships in V/Ag Multilayers

2010 ◽  
Vol 16 (S2) ◽  
pp. 1632-1633
Author(s):  
Q Wei ◽  
A Misra
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Crystallographic Orientation ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Orientation Relationships ◽  
Transmission Electron Microscopy Study ◽  
Transmission Electron

Extended abstract of a paper presented at Microscopy and Microanalysis 2010 in Portland, Oregon, USA, August 1 – August 5, 2010.

Vacancy-Assisted Precipitation in a 18 W/O Cr - 10 W/O ni - 0.3 W/O P Steel

1981 ◽  
Vol 39 ◽  
pp. 332-333
Author(s):  
A. R. Pelton
Keyword(s):  
Stainless Steel ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Austenitic Steels ◽  
Orientation Relationships ◽  
Precipitation Behavior ◽  
Vacancy Defects ◽  
Transmission Electron ◽  
Nucleation And Growth Mechanisms ◽  
Habit Planes

Although many similarities exist in the precipitation behavior in ferritic and austenitic steels, the nucleation and growth mechanisms in these systems have eluded full comprehension. However, it is apparent that the initial clustering of substitutional and interstitial atoms can dictate the structure and orientation relationships of subsequent phases. Hence, in order to realize the benefits of these decomposition transformations, a better understanding of the incipient nucleation event is imperative. Therefore, a transmission electron microscopy study of a quenched-aged 18-10 stainless steel doped with 0.3 w/o P was undertaken as part of a more comprehensive research program. The precipitation reactions in this austenitic stainless steel were originally surveyed by Rowcliffe and Nicholson [1] and Rowcliffe and Eyre [2], These investigators observed a variety of defects ranging from vacancy defects on {100} planes at lower aging temperatures to Cr3P laths with {100} habit planes at higher aging temperatures.

Transmission electron microscopy study of YNi2B2C thin film growth on MgO(001)

2004 ◽  
Vol 19 (5) ◽  
pp. 1413-1416 ◽  
Author(s):  
G.H. Cao ◽  
P. Simon ◽  
W. Skrotzki
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Film Growth ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Orientation Relationships ◽  
Cross Sectional ◽  
Transmission Electron ◽  
Mgo Substrate

A YNi2B2C thin film deposited on MgO(001) substrate by pulsed laser deposition has been investigated by transmission electron microscopy (TEM). Cross-sectional TEM analyses show that the YNi2B2C film grows in the [001] direction. Y2O3 exists not only as an interlayer at the interface of the YNi2B2C thin film and the MgO substrate but occasionally also in the YNi2B2C thin film near the substrate. The orientation relationships between the YNi2B2C thin film, Y2O3 interlayer, and MgO substrate are determined from electron-diffraction patterns to be MgO(001)[100] ‖ Y2O3(001)[100], YNi2B2C(001)[110] ‖ Y2O3(001)[100] ‖ Y2O3(001)[100, and YNi2B2C(001)[100] ‖ Y2O3(001)[100 1.5‖ Y2O3(001)[100] ‖ Y2O3(001)[100 (the numeral above the “parallel” symbol represents the misorientation (in degrees) between the [100] ‖ Y2O3(001)[100 directions).

Transmission Electron Microscopy Study of α-Decay Damage in Aeschynite and Britholite

1996 ◽  
Vol 465 ◽  
Author(s):  
W. L. Gong ◽  
L. M. Wang ◽  
R. C. Ewing ◽  
L. F. Chen ◽  
W. Lutze
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Rare Earth ◽  
Alpha Decay ◽  
High Resolution Electron Microscopy ◽  
Microscopy Study ◽  
Structure Type ◽  
Electron Microscopy Study ◽  
Α Decay ◽  
Transmission Electron

ABSTRACTThe aeschynite structure-type (Ce,Nd,La,Th,U,Ca)(Nb,Ti)2O6, and the rare-earth silicate apatite structure-type with the formula (Ce,La,Nd,Ca,Th)10(SiO4,PO4)6(O,F,OH)2 are important rare-earth and actinide host phases for high-level nuclear waste. Natural phases of these structure-types have calculated alpha-decay doses up to ∼1017 α-events/mg which have accumulated over hundreds of millions of years. Transmission electron microscopy has been used to study the microstructure of α-decay damage in aeschynite and britholite. Electron diffraction analysis of natural aeschynite revealed that minerals originally crystalline gradually lost their crystallinity with increasing alpha-decay doses. Helium bubbles were found in the aeschynite which have accumulated up to ∼2×1016 α-events/mg. These bubbles may nucleate within collision cascades during a-decay damage. Electron irradiation has an enhanced rare-gas migration and the formation of larger bubbles. High-resolution electron microscopy (HRTEM) revealed that amorphization during accumulation of a-decay damage was from alpha-recoil nuclei collision cascades, in both the aeschynite and britholite.

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