scholarly journals Relationship between Microstructure and Properties of Cu–Cr–Ag Alloy

Materials ◽  
2020 ◽  
Vol 13 (3) ◽  
pp. 732
Author(s):  
Dong Liang ◽  
Xujun Mi ◽  
Lijun Peng ◽  
Haofeng Xie ◽  
Guojie Huang ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Cold Deformation ◽  
Solution Treatment ◽  
Aging Treatment ◽  
Face Centered Cubic ◽  
Transmission Electron ◽  
The Matrix ◽  
Bcc Structure ◽  
Continuous Extrusion ◽  
Face Centered

The microstructure evolution and properties of a Cu–Cr–Ag alloy during continuous extrusion and an aging process were studied by Scanning Electron Microscope (SEM) and Transmission Electron Microscope (TEM). Owing to strong shear deformation that happened during continuous extrusion with working temperatures of 450 to 480 °C, a larger number of fine grains were obtained. Both face-centered cubic (FCC) and body-centered cubic (BCC) precipitates simultaneously existed in the matrix when aged for 450 °C for 2 h, and the Cr phases with BCC structure had an N–W relationship with the matrix. After continuous extrusion, 60% cold deformation, 875 °C × 1 h solid solution treatment, 60% cold deformation, 450 °C × 2 h aging treatment, and 70% cold deformation, the Cu–Cr–Ag alloy acquired excellent comprehensive properties: tensile strength of 494.4 MPa, yield strength of 487.6 MPa, and electrical conductivity of 91.4% IACS.

TEM Study for Strengthening Mechanisms in Elgiloy

2010 ◽  
Vol 442 ◽  
pp. 268-274 ◽  
Author(s):  
I.N. Qureshi ◽  
S. Rani ◽  
F. Yasmin ◽  
M. Farooque
Keyword(s):  
Electron Microscope ◽  
Cold Work ◽  
Cold Deformation ◽  
Solution Treatment ◽  
Optical Microscope ◽  
Age Hardening ◽  
Solution Treated ◽  
Transmission Electron ◽  
P Transformation ◽  
Cold Worked

Elgiloy is Co based alloy (40wt%Co, 20wt%Cr, 15wt%Ni, 14wt%Fe and 7wt%Mo). It was strengthened by cold work and is capable of additional hardening by aging. The effects of solution treatment, cold working and age-hardening on the microstructure of elgiloy were investigated using optical microscope, scanning electron microscope (SEM) and transmission electron microscope (TEM). As rolled strips were solution treated at 1065°C/1hr. These solution treated strips were then reduced 50% by cold rolling. After cold-deformation both є-hcp phase and fcc deformation twins are also considered to coexist at room temperature. The cold worked strips were then age hardened at (450-600)°C. The age hardened strips showed formation of additional є-phase (via α f c c є h c p transformation).

Research on the Microstructure of Solid FeS by TEM

2011 ◽  
Vol 217-218 ◽  
pp. 1098-1101
Author(s):  
Li Na Zhu ◽  
Cheng Biao Wang ◽  
Hai Dou Wang ◽  
Bin Shi Xu ◽  
Jia Jun Liu ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Electron Diffraction ◽  
Transmission Electron Microscope ◽  
Solid Lubricant ◽  
Hexagonal Structure ◽  
Face Centered Cubic ◽  
Transmission Electron ◽  
Different Shapes ◽  
Cubic Structure ◽  
Face Centered

The microstructures of three kinds of synthetical solid FeS, acting as a solid lubricant, which includes FeS bulk, FeS particle and FeS powder, were studied by transmission electron microscope (TEM) in this article. The TEM photographs showed that different shapes of FeS had quite dissimilar characteristics. The texture of FeS powder was the loosest among the three shapes, and it tended to forming flocculent aggregation; while FeS bulk and FeS particle were more dispersive. The electron diffraction results showed that the crystals of solid FeS were composed of many single crystals and multi-crystals, with two kinds of crystalline structure- hexagonal structure and face-centered cubic structure.

MICROSTRUCTURE AND FRACTURE TOUGHNESS OF FeNiCr-TiC COMPOSITE PRODUCED BY THERMITE REACTION

2010 ◽  
Vol 24 (15n16) ◽  
pp. 2904-2909
Author(s):  
WENJUN XI ◽  
CHAOLIANG SHI
Keyword(s):  
Fracture Toughness ◽  
Electron Microscope ◽  
Aging Temperature ◽  
Aging Treatment ◽  
Ferrite Matrix ◽  
Β Phase ◽  
Transmission Electron ◽  
The Matrix ◽  
Average Size ◽  
Effects Of Aging

The microstructures of the FeNiCr - TiC composite produced by the rapid solidification thermite process were investigated using X-ray diffraction (XRD), scanning electron microscope (SEM) and transmission electron microscope (TEM). The effects of aging treatment on the microstructure and fracture toughness of the composite were examined. Results showed that the FeNiCr - TiC composite was composed of ferrite (α- FeNiCr ), TiC and NiAl (β phase). TiC particles in the matrix were in the shape of polygon and uniformly distributed, and their size was less than 3 µm. The β phase was coherent with the ferrite matrix, and its average size was about 50 nm. The fracture toughness of composite was 22 MPa·m1/2 without aging. When the aging temperature was below 600°C, the fracture toughness of the composite had higher plateau values and reached the maximum of 32 MPa·m1/2 at aging temperature 500°C due to the precipitation of NiAl phase on the nanometer scale. The fracture toughness decreased rapidly aged at 650°C, and then kept homology value in the range of 700 to 900°C, which was attributed to the precipitation of needle-shaped carbide ( Cr / Fe )7 C 3 at the grain boundaries.

Research on Solution and Aging Treatment of Mg-7Zn-3Al Alloy

2007 ◽  
Vol 561-565 ◽  
pp. 247-250
Author(s):  
Jing Zhang ◽  
Fu Sheng Pan ◽  
Ru Lin Zuo
Keyword(s):  
Electron Microscopy ◽  
Grain Boundary ◽  
Volume Fraction ◽  
Solution Treatment ◽  
Aging Treatment ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Quantitative Image ◽  
The Matrix

Effect of solution and aging treatment on the microstructure of Mg-7Zn-3Al alloy is studied by using optical microscopy, scanning electron microscopy, X-ray diffraction, transmission electron microscopy and quantitative image analysis. The results show that the as-aged microstructure is composed of α-Mg matrix, grain boundary τ (Mg32(Al,Zn)49 ) phase, and fine dispersed τ particles inside the grain. The solution degree has significant effects on the formation, morphology, and size of the grain boundary τ phase. The volume fraction and the size of the undissolved eutectic τ phase decrease with the increase of solution time treated at 325°C. Through sufficient solution treatment, discontinuous eutectic τ phase retains fine strip morphology after aging, in contrast to the microstructure in sample undergone insufficient solution which manifests as-cast feature, while at the same time nano-sized particles precipitate out from the matrix. The precipitates display paralleled short bar, having certain orientation relationship with the matrix.

scholarly journals Microstructure and Properties of Diffusion Bonded Mg/Al Joints

2019 ◽  
Vol 804 ◽  
pp. 29-34
Author(s):  
Yun Long Ding ◽  
Dong Ying Ju
Keyword(s):  
Tensile Strength ◽  
Electron Microscope ◽  
Elemental Distribution ◽  
Face Centered Cubic ◽  
Electron Probe Micro Analyzer ◽  
Diffusion Layers ◽  
Transmission Electron ◽  
Face Centered ◽  
Bonding Method ◽  
Alloy 6061

In this study, magnesium alloy AZ31 was successfully welded with aluminum alloy 6061 by diffusion bonding method. In addition, annealing process was applied to refine micro-structure and improve mechanical property. Microstructure and elemental distribution of interface were investigated with Scanning Electron Microscope (SEM) and Electron Probe Micro Analyzer (EPMA). Furthermore, experiments on diffusion bonded specimens with the usage of Transmission Electron Microscope (TEM) were carried out. At last, tensile strength was measured. It can be obtained that the width of diffusion layers increase with the increasing annealing temperatures. Elemental distribution of specimens with annealing were more uniform than that without annealing. The intermetallic compounds in diffusion layers are Al3Mg2 and Al12Mg17, their crystal structure are respectively face-centered cubic (fcc) and body-centered cubic (bcc). What’s more, tensile strength turns to be strongest after annealing at 250°C.

scholarly journals Effects of C Addition on the Microstructures of As-Cast Cu–Fe–P Alloys

Materials ◽  
2019 ◽  
Vol 12 (17) ◽  
pp. 2772 ◽  
Author(s):  
Chen ◽  
Hu ◽  
Guo ◽  
Zou ◽  
Liu ◽  
...  
Keyword(s):  
Orientation Relationship ◽  
Supersaturated Solid Solution ◽  
Face Centered Cubic ◽  
Body Centered Cubic ◽  
Matrix Microstructure ◽  
The Matrix ◽  
Bcc Structure ◽  
The Difference ◽  
Face Centered ◽  
Fcc Structure

Effects of C addition on the microstructures of as-cast Cu–Fe–P (mass fraction) alloys were systematically investigated. The results show that C addition can refine the matrix microstructure and make Fe particles finer. The Fe particles observed in both the non-C-alloyed and C-alloyed specimens are α-Fe particles, which possess a body-centered cubic (bcc) structure with a Nishiyama–Wassermann orientation relationship with the matrix. C is reported to be an γ-Fe stabilizer in the literature. The reason for the difference between the phases of Fe particles observed in this study, and that reported in the literature, are finally discussed. Additionally, C addition facilitates the decomposition of the supersaturated solid solution which occurs by the simultaneous precipitation of very fine Fe particles. Such initial decomposition product has an face-centered cubic (fcc) structure with a cube-on-cube orientation relationship with the matrix.

scholarly journals Characterization of crystal structure and precipitation crystallography of a new MgxAl2−xGd phase in an Mg97Al1Gd2alloy

2016 ◽  
Vol 49 (4) ◽  
pp. 1177-1181 ◽  
Author(s):  
X.-F. Gu ◽  
T. Furuhara
Keyword(s):  
Crystal Structure ◽  
Lattice Parameter ◽  
Face Centered Cubic ◽  
Laves Phases ◽  
Transmission Electron ◽  
Scanning Transmission ◽  
The Matrix ◽  
The Face ◽  
Face Centered

The composition, crystal structure and precipitation crystallography of a newly found precipitate are characterized by Cs-corrected scanning transmission electron microscopy. The composition of the plate-like precipitate could be expressed as MgxAl2−xGd (x= 0.38), and its crystal structure is the same as the face-centered cubic type Laves phases Mg2Gd and Al2Gd, with a lattice parameter of 7.92 Å (space group No. 227, Fd\overline 3m). The orientation relationship between the matrix and precipitate is found to be (0001)m//(111)pand [10\overline 10]m//[1\overline 10]p, and the habit plane is parallel to the (0001)m//(111)pplane. In addition, this preferred crystallography of phase transformation is well explained on the basis of the atomic matching at the interface.

Preparation and Characterization of Silver Powders with Spheric Shape and Different Sizes

2010 ◽  
Vol 152-153 ◽  
pp. 1805-1809
Author(s):  
Ming Li Li ◽  
Kun Ming Qian ◽  
Qiong Yu ◽  
Yu Song Zhou ◽  
Song Ji ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Chemical Reduction ◽  
Silver Ions ◽  
Face Centered Cubic ◽  
Dispersing Agent ◽  
Transmission Electron ◽  
Particle Size Analyzer ◽  
Tap Density ◽  
Face Centered

The preparation and characterization of silver powders with spheric shape and different sizes by chemical reduction of silver ions in the presence of ethanol amine using hydrochinone (C6H6O2) as the reducing agent are described. The size distribution, microstructure, and the phase composition of the obtained Ag Powders were characterized by the Laser Particle Size Analyzer, Scanning Electron Microscope (SEM), Transmission Electron Microscope (TEM) and the X-ray diffraction (XRD). The Ag powder was in face-centered cubic crystal structure with spheric morphology. The average tap density of silver powders is up to 4.0g/cm3. It was also found that the size of the Ag particles can be adjusted conveniently to a certain degree by varying the silver ions content, the addition amount of dispersing agent, the aging time, the temperature of the reaction, and the concentration ratio of hydrochinone to Ag+.

Influence of Heat Treatments on Microstructures in an Fe-Co-V Alloy

1974 ◽  
Vol 32 ◽  
pp. 512-513
Author(s):  
S. Mahajan ◽  
M. R. Pinnel ◽  
J. E. Bennett
Keyword(s):  
Single Phase ◽  
Alloy Composition ◽  
Supersaturated Solid Solution ◽  
Cell Formation ◽  
Heat Treatments ◽  
Air Cooling ◽  
Iced Brine ◽  
Transmission Electron ◽  
The Matrix ◽  
Bcc Structure

The microstructural changes in an Fe-Co-V alloy (composition by wt.%: 2.97 V, 48.70 Co, 47.34 Fe and balance impurities, such as C, P and Ni) resulting from different heat treatments have been evaluated by optical metallography and transmission electron microscopy. Results indicate that, on air cooling or quenching into iced-brine from the high temperature single phase ϒ (fcc) field, vanadium can be retained in a supersaturated solid solution (α2) which has bcc structure. For the range of cooling rates employed, a portion of the material appears to undergo the γ-α2 transformation massively and the remainder martensitically. Figure 1 shows dislocation topology in a region that may have transformed martensitically. Dislocations are homogeneously distributed throughout the matrix, and there is no evidence for cell formation. The majority of the dislocations project along the projections of <111> vectors onto the (111) plane, implying that they are predominantly of screw character.

Faceted antiphase boundaries in GaAs grown on Ge

1987 ◽  
Vol 45 ◽  
pp. 314-315
Author(s):  
N.-H. Cho ◽  
S. McKernan ◽  
C.B. Carter ◽  
K. Wagner
Keyword(s):  
Cross Section ◽  
Atomic Resolution ◽  
Face Centered Cubic ◽  
Electrical Behavior ◽  
Sphalerite Structure ◽  
Antiphase Boundaries ◽  
Transmission Electron ◽  
Face Centered ◽  
Quality Material ◽  
Simulated Images

Interest has recently increased in the possibility of growing III-V compounds epitactically on non-polar substrates to produce device quality material. Antiphase boundaries (APBs) may then develop in the GaAs epilayer because it has sphalerite structure (face-centered cubic with a two-atom basis). This planar defect may then influence the electrical behavior of the GaAs epilayer. The orientation of APBs and their propagation into GaAs epilayers have been investigated experimentally using both flat-on and cross-section transmission electron microscope techniques. APBs parallel to (110) plane have been viewed at the atomic resolution and compared to simulated images.Antiphase boundaries were observed in GaAs epilayers grown on (001) Ge substrates. In the image shown in Fig.1, which was obtained from a flat-on sample, the (110) APB planes can be seen end-on; the faceted APB is visible because of the stacking fault-like fringes arising from a lattice translation at this interface.

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