Microstructure and Properties of Cu-Cr-Zr-Ag Alloy

2018 ◽  
Vol 941 ◽  
pp. 1613-1617 ◽  
Author(s):  
Li Jun Peng ◽  
Xu Jun Mi ◽  
Hao Feng Xie ◽  
Yang Yu ◽  
Guo Jie Huang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Phase Transformation ◽  
High Resolution ◽  
Aging Process ◽  
Precipitation Sequence ◽  
Transmission Microscopy ◽  
Transmission Electron ◽  
The Matrix

The Cr precipitation sequence in Cu-Cr-Zr-Ag alloy during the aging process at 450°C could be obtained by Transmission electron microscopy (TEM) and High-resolution transmission microscopy (HRTEM) in the study. The strengthening curve shows a unimodal type and the tensile strength trends to peak when the aged for 4h. The Cr phase transformation of Cu-Cr-Zr-Ag aged at 450°C is supersaturated solid sloution→G.P zones→fcc Cr phase→order fcc Cr phase→bcc Cr phase. The orientation relationship between bcc Cr precipitates and the matrix change from cube-on-cube to NW-OR.

Characterization of Al2O3 in High-Strength Mo Alloy Sheets by High-Resolution Transmission Electron Microscopy

2016 ◽  
Vol 22 (1) ◽  
pp. 122-130 ◽  
Author(s):  
Yucheng Zhou ◽  
Yimin Gao ◽  
Shizhong Wei ◽  
Yajie Hu
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
High Resolution ◽  
Boundary Migration ◽  
Recrystallization Temperature ◽  
Rolled Sheet ◽  
Transmission Electron ◽  
Diffraction Patterns

AbstractA novel type of alumina (Al2O3)-doped molybdenum (Mo) alloy sheet was prepared by a hydrothermal method and a subsequent powder metallurgy process. Then the characterization of α-Al2O3 was investigated using high-resolution transmission electron microscopy as the research focus. The tensile strength of the Al2O3-doped Mo sheet is 43–85% higher than that of the pure Mo sheet, a very obvious reinforcement effect. The sub-micron and nanometer-scale Al2O3 particles can increase the recrystallization temperature by hindering grain boundary migration and improve the tensile strength by effectively blocking the motion of the dislocations. The Al2O3 particles have a good bond with the Mo matrix and there exists an amorphous transition layer at the interface between Al2O3 particles and the Mo matrix in the as-rolled sheet. The sub-structure of α-Al2O3 is characterized by a number of nanograins in the $\left[ {2\bar{2}1} \right]$ direction. Lastly, a new computer-based method for indexing diffraction patterns of the hexagonal system is introduced, with 16 types of diffraction patterns of α-Al2O3 indexed.

In-Situ High Resolution Transmission Electron Microscopy of Dynamic Events During the Amorphous to Crystalline Phase Transformation in Silicon

1985 ◽  
Vol 62 ◽  
Author(s):  
M. A. Parker ◽  
T. W. Sigmon ◽  
R. Sinclair
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Phase Transformation ◽  
Solid State ◽  
High Resolution ◽  
Elevated Temperatures ◽  
Video Recording ◽  
Dynamic Events ◽  
Transmission Electron

ABSTRACTA technique has been developed which employs high resolution transmission electron microscopy (HRTEM) for the observation of the atomic mechanisms associated with solid state phase transformation as they occur at elevated temperatures. It consists of the annealing in-situ of cross-section transmission electron microscopy (TEM) specimens that have been favorably oriented for lattice fringe imaging and the video-recording of dynamic events as they occur in real-time. By means of this technique, we report the first video-recorded lattice images of crystallographic defect motion in silicon, viz. the motion of dislocations and stacking faults, as well as the first such images of the atomic mechanisms responsible for the amorphous to crystalline (a-c) phase transformation, viz. heterogeneous nucleation of crystal nuclei, coalescence of crystal nuclei by co-operative atomic processes, ledge motion at the growth interface, and normal growth in silicon. This technique holds great potential for the elucidation of the atomic mechanisms involved in reaction kinetics in the solid state.

Study of Precipitation Sequence in Al-Mg-Si Alloys by HRTEM

2005 ◽  
Vol 475-479 ◽  
pp. 361-364 ◽  
Author(s):  
Kenji Matsuda ◽  
Susumu Ikeno
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Low Temperature ◽  
Early Stage ◽  
Metastable Phases ◽  
Precipitation Sequence ◽  
Mono Layer ◽  
Transmission Electron

The precipitation sequence of Al-Mg-Si alloys has been studied by high-resolution transmission electron microscopy (HRTEM). G.P. zone is a fine-plate having dimensions of a mono- layer in thickness, 2.5nm in width, and less than 30nm in length. Its elongated direction is parallel to the <100>m direction. Several types of metastable phases were observed in the excess Si alloy and they were classified with the b ’-phase in the balanced alloy. Especially, the b ”-phase was the typical phase in the excess Si alloy aged at low temperature or at the early stage during aging.

Metal/ceramic interface in an in situsynthesized Ti/TiCP composite coating by laser processing

2001 ◽  
Vol 16 (1) ◽  
pp. 9-12 ◽  
Author(s):  
R. Yu ◽  
S. Zhang ◽  
L. L. He ◽  
W. T. Wu ◽  
H. Q. Ye
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Composite Coating ◽  
Laser Processing ◽  
Transmission Electron ◽  
Metal Ceramic ◽  
The Matrix ◽  
Metallic Bonding

The metal/ceramic interface in an in situ synthesized Ti/TiCP composite coating by laser processing was analyzed using high-resolution transmission electron microscopy. The TiC particles were distributed uniformly in the matrix and were highly faceted. The interfaces between the TiC particles and the β matrix were abrupt and free of any other reaction phases. It was the Ti-terminated TiC surface that bonded to the β matrix, resulting in the metallic bonding between the TiC particles and the matrix.

Microstructure and Mechanical Properties of SiC/zirconia-toughened Mullite Nanocomposites Prepared from Mixtures of Mullite Gel, 2Y-TZP, and SiC Nanopowders

2002 ◽  
Vol 17 (5) ◽  
pp. 1024-1029 ◽  
Author(s):  
X. H. Jin ◽  
L. Gao ◽  
L. H. Gui ◽  
J. K. Guo
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Grain Boundaries ◽  
Low Energy ◽  
Liquid Interfaces ◽  
Sic Nanoparticles ◽  
Transmission Electron ◽  
The Matrix

SiC/ZTM (zirconia-toughened mullite) nanocomposites were prepared by hot pressing mixtures of mullite gel, 2Y-TZP, and SiC nanopowders. The intimate mixing of Al2O3 and SiO2 components in the starting powder prevented intermediate ZrSiO4 phase formation during sintering. Addition of nano-sized SiC significantly retarded the matrix grain growth, making the microstructure much finer and more uniform. Transmission electron microscopy and high-resolution transmission electron microscopy revealed that many SiC nanoparticles were found in mullite and ZrO2 grains, and low-energy grain boundaries and mullite–liquid interfaces parallel to the {110} planes of rodlike mullite grains were formed. It is deduced that the formation of rodlike mullite grains is the result of the preferential development of these low-energy grain boundaries and mullite–liquid interfaces. The mechanical properties of the SiC/ZTM nanocomposite showed significant improvement over those of ZTM, and further enhancement in the mechanical properties was achieved by combinative strengthening with nano- and micro-sized SiC.

Preparation of Titanium Microgrids for Scanning Transmission Electron Microscopy

1977 ◽  
Vol 35 ◽  
pp. 322-323
Author(s):  
M.L. Collins ◽  
N.W. Parker
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
High Resolution ◽  
Scanning Transmission Electron Microscopy ◽  
Single Atom ◽  
Specimen Preparation ◽  
Transmission Microscopy ◽  
Scanning Transmission Electron ◽  
Transmission Electron ◽  
Scanning Transmission

The ideal supporting microgrid for high resolution scanning transmission electron microscopy should be: 1) made of material of low atomic number, 2) uniformly flat for ease in focusing, 3) resistant to any treatments necessary for cleaning and specimen preparation, and 4) a good electrical and thermal conductor. In the past, microgrid supports have been made of fenestrated plastic films strengthened by carbon or metal coatings. While adequate for most work, they cannot be baked at temperatures greater than 50°C. which may be necessary in some cases to completely eliminate contamination for single atom imaging using the STEM. To provide a reliably non-contaminating substrate support for high resolution scanning transmission microscopy, we have developed a simple technique for the preparation of microgrids of titanium metal. As can be seen in table 1, titanium posesses many attractive features.

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.

Phase Transformations in Ti-7w/oMo-3w/oMe Alloy

1974 ◽  
Vol 32 ◽  
pp. 514-515
Author(s):  
S. Fujishiro
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Transmission Electron Microscopy ◽  
Tensile Strength ◽  
Mechanical Processing ◽  
Ray Method ◽  
X Ray ◽  
Transmission Electron ◽  
Water Quench ◽  
Alpha Beta

The mechanical properties of three titanium alloys (Ti-7Mo-3Al, Ti-7Mo- 3Cu and Ti-7Mo-3Ta) were evaluated as function of: 1) Solutionizing in the beta field and aging, 2) Thermal Mechanical Processing in the beta field and aging, 3) Solutionizing in the alpha + beta field and aging. The samples were isothermally aged in the temperature range 300° to 700*C for 4 to 24 hours, followed by a water quench. Transmission electron microscopy and X-ray method were used to identify the phase formed. All three alloys solutionized at 1050°C (beta field) transformed to martensitic alpha (alpha prime) upon being water quenched. Despite this heavily strained alpha prime, which is characterized by microtwins the tensile strength of the as-quenched alloys is relatively low and the elongation is as high as 30%.

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