Stress-induced C14→C15 phase transformation in a Zr(Fe,Cr)2 Laves structured nanophase

2020 ◽  
Vol 53 (1) ◽  
pp. 222-225 ◽  
Author(s):  
Fusen Yuan ◽  
Chengze Liu ◽  
Fuzhou Han ◽  
Yingdong Zhang ◽  
Ali Muhammad ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phase Transformation ◽  
Phase Boundary ◽  
Shear Deformation ◽  
Orientation Relationship ◽  
Stacking Faults ◽  
Hexagonal Close Packed ◽  
Partial Dislocations ◽  
Transmission Electron

The C14 (hexagonal close-packed) and C15 (face-centred cubic) close-packed structures are found to coexist in an individual Zr(Fe,Cr)2 Laves structured nanophase in Zircaloy-4 alloy with shear deformation. The orientation relationship between C15 and C14 is [\bar 1 10]C15//[11\bar 20]C14 and (\bar 111)C15//(0001)C14. The stacking faults (SFs) in the C15 structure and the high-density SFs between C15 and C14 have been identified using transmission electron microscopy, which showed they originated on close-packed planes by emission of 1/6〈\bar 2 \bar 1\bar 1〉 Shockley partial dislocations from the phase boundary. Furthermore, the stress-induced C14→C15 phase transformation took place during the shear deformation.

Dislocations and stacking faults in stainless steel

1957 ◽  
Vol 240 (1223) ◽  
pp. 524-538 ◽  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Stainless Steel ◽  
Grain Boundaries ◽  
Stacking Faults ◽  
Stacking Fault ◽  
Stacking Fault Energy ◽  
Thin Sections ◽  
Partial Dislocations ◽  
Transmission Electron

Further experiments by transmission electron microscopy on thin sections of stainless steel deformed by small amounts have enabled extended dislocations to be observed directly. The arrangement and motion of whole and partial dislocations have been followed in detail. Many of the dislocations are found to have piled up against grain boundaries. Other observations include the formation of wide stacking faults, the interaction of dislocations with twin boundaries, and the formation of dislocations at thin edges of the foils. An estimate is made of the stacking-fault energy from a consideration of the stresses present, and the properties of the dislocations are found to be in agreement with those expected from a metal of low stacking-fault energy.

Dynamical Study of Dislocations and 4H → 3C Transformation Induced by Stress in (11-20) 4H-SiC

2005 ◽  
Vol 483-485 ◽  
pp. 299-302 ◽  
Author(s):  
Hosni Idrissi ◽  
Maryse Lancin ◽  
Joel Douin ◽  
G. Regula ◽  
Bernard Pichaud
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Chemical Etching ◽  
Stacking Faults ◽  
Sample Surface ◽  
Cubic Phase ◽  
Dynamical Study ◽  
Weak Beam ◽  
Partial Dislocations ◽  
Transmission Electron

4H-SiC samples were bent in compression mode at temperature ranging from 400°C to 700°C. The introduced-defects were identified by Weak Beam (WB) and High Resolution Transmission Electron Microscopy (HRTEM) techniques. They consist of double stacking faults bound by 30° Si(g) partial dislocations whose glide locally transforms the material in its cubic phase. The velocity of partial dislocations was measured after chemical etching of the sample surface. The formation and the expansion of the double stacking faults are discussed.

Transmission electron microscope investigation of indentation induced dislocation configurations on the (001) GaSb face

1994 ◽  
Vol 209 (3) ◽  
Author(s):  
J. Doerschel
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Electron Microscope ◽  
Transmission Electron Microscope ◽  
Room Temperature ◽  
Stacking Faults ◽  
Electron Microscope Investigation ◽  
Partial Dislocations ◽  
Transmission Electron ◽  
Induced Dislocation

AbstractDislocation configurations induced by room temperature microindentations on the (001) face of GaSb (undoped and Te-doped) have been studied using high voltage transmission electron microscopy. Perfect and partial dislocations could be found in all four arms of the dislocation rosette around the indent. Microtwins and rarely single stacking faults are associated with the partials. Contrary to other binary III–V compounds, an “inverse” glide prism along the [1[unk]0]/[[unk]10] rosette arms is created and it is bounded by {111}

Phase Formation and Hydrogen Ordering in Yttrium-Hydrogen System

2009 ◽  
Vol 1216 ◽  
Author(s):  
Ke Wang ◽  
Jason Hattrick-Simpers ◽  
Leonid Bendersky
Keyword(s):  
Electron Microscopy ◽  
Phase Transition ◽  
Transmission Electron Microscopy ◽  
Phase Transformation ◽  
Electron Diffraction ◽  
Twin Boundaries ◽  
Sapphire Substrates ◽  
Partial Dislocations ◽  
Transmission Electron ◽  
New Type

AbstractPhase transformations in epitaxial yttrium films grown on (0001)Ti//(0001)Al2O3 Ti-buffered sapphire substrates and hydrogenated for 10 min were characterized using transmission electron microscopy. After hydrogen charging, dense twin lamellae form during α(Y(H))-to-β(YH2) phase transition with twin boundaries predominately parallel to the interface between Y and a substrate. High densities of Shockley partial dislocations are present at the twin boundaries, their glides during phase transformation are responsible for the formation of twin lamellae. Electron diffraction from YH2 phase shows superlattice reflections, which suggests a new type of ordering on octahedral interstitial sites.

Metal-ZnO Interfaces Studied by High Resolution Transmission Electron Microscopy

1996 ◽  
Vol 466 ◽  
Author(s):  
J.Th.M. De Hosson ◽  
W. P. Vellinga ◽  
H. B. Groen ◽  
B. J. Kooi
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Orientation Relationship ◽  
Internal Oxidation ◽  
Atomic Structure ◽  
Orientation Relation ◽  
Partial Dislocations ◽  
Transmission Electron ◽  
The Matrix

ABSTRACTThis paper reports on investigations of Ag-ZnO and Cu-ZnO interfaces, produced by internal oxidation. ZnO precipitates with the wurtzite structure were found showing mainly one orientation relationship (OR) with the matrix. However, closely related ORs were found, rotated by small angles from that orientation relation. The atomic structure of several interfaces surrounding these precipitates was studied and compared using high resolution transmission electron microscopy. This paper focuses on interfaces between low index facets of ZnO and vicinal planes of Ag. These interfaces clearly show relaxations. An interpretation of these relaxations in terms of dissociation of partial dislocations at the interface is put forward.

Interfacial precipitation in titania-doped diphasic mullite gels

1998 ◽  
Vol 13 (4) ◽  
pp. 974-978 ◽  
Author(s):  
Seong-Hyeon Hong ◽  
Naesung Lee ◽  
Altaf H. Carim ◽  
Gary L. Messing
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Phase Transformations ◽  
Orientation Relationship ◽  
Sol Gel ◽  
Sintered Body ◽  
Transmission Electron

Interfacial precipitation in sol-gel derived, titania-doped diphasic mullite gels was investigated using conventional and high resolution transmission electron microscopy. Rutile, anatase, and brookite precipitated on the interface between {110} planes of mullite and glass pockets in the sintered body. The formation of brookite may be attributable to the Si- and Al-rich environment during precipitation. Each polymorph of titania has a unique morphology and orientation relationship with mullite. Brookite exhibits a truncated pill box shape, and anatase displays a vermicular morphology. Quenching experiments suggest that the precipitates grow and undergo phase transformations during cooling.

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