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.

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.

Effect of Aging Treatment on Microstructure and Mechanical Properties of a Two-Phase Titanium Alloy

2010 ◽  
Vol 654-656 ◽  
pp. 851-854
Author(s):  
Miao Song ◽  
Jia Feng Lei ◽  
Ying Jie Ma ◽  
Yu Yin Liu
Keyword(s):  
Electron Microscopy ◽  
Fracture Toughness ◽  
Quantitative Analysis ◽  
Aging Temperature ◽  
Aging Treatment ◽  
Large Area ◽  
Two Phase ◽  
Rich Phase ◽  
Α Phase ◽  
Transmission Electron

In present work, microstructure of Ti-6Al-2Mo-1.5Cr-2Sn-2Zr-1V-0.15Si-0.4Fe alloy as a function of aging temperature was investigated using optical microscopy, scanning electron microscopy (SEM), x-ray diffraction (XRD) and transmission electron microscopy (TEM).Three types of precipitates were found in this alloy, they were α2 phase (Ti3Al), silicides, and Sn rich phase. Ti3Al were observed in all aged specimens covering a range 500-740°C. A method of quantitative analysis toward α2 based on high resolution images and Flourier transformation is used. The results showed that the ordering in α phase was highly related to the property of fracture toughness. Silicides were first found at 580°C ageing and later determined in the formulate (Ti5+xZr3-x)Si3 in the specimens aged at 740°C, and they were found to influent the fracture toughness significantly. The Sn rich phase was emerged with large area during the 780°C aging. And its direct correlation to property was not found. The density of acicular α phase was found almost invariable by calculating through the modification XRD quantitative analysis during the elevated aging temperature.

Organoclay-reinforced polyethersulfone-modified epoxy-based hybrid nanocomposites

2011 ◽  
Vol 23 (7) ◽  
pp. 526-534 ◽  
Author(s):  
Yang Wang ◽  
Boming Zhang ◽  
Jinrui Ye
Keyword(s):  
Electron Microscopy ◽  
Fracture Toughness ◽  
Electron Microscope ◽  
Optical Microscope ◽  
Mechanical Analysis ◽  
Hybrid Nanocomposites ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
Modified Epoxy ◽  
Scanning Electron

Hybrid nanocomposites were successfully prepared by the incorporation of polyethersulfone (PES) and organoclay into epoxy resin. They had higher fracture toughness than the prepared PES/epoxy blend and organoclay/epoxy nanocomposites. The microstructures of the hybrid nanocomposites were studied. They were comprised of homogeneous PES/epoxy semi-interpenetrating network (semi-IPN) matrices and organoclay micro-agglomerates made up of tactoid-like regions composed of ordered exfoliated organoclay with various orientations. The former was confirmed with dynamic mechanical analysis, scanning electron microscopy and transmission electron microscopy, while the latter was successfully observed with X-ray diffraction measurements, optical microscope, scanning electron microscope and transmission electron microscope. The improvement of their fracture toughness was due to the synergistic toughening effect of the PES and the organoclay and related to their microstructures.

Transmission Electron Microscope Specimen Preparation of Metal Matrix Composites Using the Focused Ion Beam Miller

2000 ◽  
Vol 6 (5) ◽  
pp. 452-462 ◽  
Author(s):  
Julie M. Cairney ◽  
Robert D. Smith ◽  
Paul R. Munroe
Keyword(s):  
Electron Microscope ◽  
Metal Matrix Composites ◽  
Transmission Electron Microscope ◽  
Metal Matrix ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Matrix Composites ◽  
Transmission Electron ◽  
The Matrix ◽  
Ceramic Reinforcement

AbstractTransmission electron microscope samples of two types of metal matrix composites were prepared using both traditional thinning methods and the more novel focused ion beam miller. Electropolishing methods were able to produce, very rapidly, thin foils where the matrix was electron transparent, but the ceramic reinforcement particles remained unthinned. Thus, it was not possible in these foils to study either the matrix-reinforcement interface or the microstructure of the reinforcement particles themselves. In contrast, both phases in the composites prepared using the focused ion beam miller thinned uniformly. The interfaces in these materials were clearly visible and the ceramic reinforcement was electron transparent. However, microstructural artifacts associated with ion beam damage were also observed. The extent of these artifacts and methods of minimizing their effect were dependent on both the materials and the milling conditions used.

Effect of Aging Treatment on Damping Capacity in Mncunife Alloy

2012 ◽  
Vol 246-247 ◽  
pp. 1158-1162
Author(s):  
Xu Fu ◽  
Ning Li ◽  
Yu Hua Wen ◽  
Jing Teng ◽  
Ying Zhang
Keyword(s):  
Electron Microscope ◽  
Aging Treatment ◽  
Damping Capacity ◽  
Torsion Pendulum ◽  
X Ray Diffraction ◽  
X Ray ◽  
Transmission Electron ◽  
Higher Temperature ◽  
Lower Temperature ◽  
The Relationship

M2052 alloys with various aging treatments are obtained in order to investigate the relationship between aging treatment and damping capacity by the torsion pendulum, X-Ray Diffraction (XRD) and Transmission Electron Microscope (TEM) methods. The results show that M2052 can obtain high damping capacity (δ>0.2) when aged at a range from 400°C to 450°C, and the damping capacity after aged at a lower temperature is higher than that aged at a higher temperature for the maximum values. TEM and XRD results show that fcc-fct transformation occurs after aging treatment. The volumes of fct structures are one of reason to affect the damping capacity in M2052 alloy. The better understanding aging treatment could promote the applications of M2052 alloy.

Microstructure and Mechanical Properties of a Cu-Pd-Ag Alloy Wire with Aging Treatment

2018 ◽  
Vol 941 ◽  
pp. 1167-1172
Author(s):  
Chihiro Iwamoto ◽  
Fumio Watanabe ◽  
Risei Koitabashi
Keyword(s):  
Electronic Device ◽  
Aging Treatment ◽  
Age Hardening ◽  
Nanoindentation Test ◽  
Alloy Wire ◽  
Hardening Mechanism ◽  
Β Phase ◽  
Α Phase ◽  
The Matrix ◽  
The Wire

Cu-Pd-Ag alloy is widely used in electronic device applications due to its relatively low electric resistance. To obtain higher strength wire, age-hardening is usually conducted to this alloy wire. However, the detailed hardening mechanism of Cu-Pd-Ag alloy was not clarified enough. In the present paper, we investigated the microstructure and hardness of the Cu-Pd-Ag alloy wire with aging treatment. Original alloy contained many rods with an Ag-rich α phase extended along the wire direction in a Cu-rich α phase matrix. After heat treatment of 623K with 1 hour, the matrix was transformed to the β phase contained many elongated α2 phases as nanolamellar structure. Many β’ phase precipitated in the rods. Hardness measured with nanoindentation test showed that the matrix had a higher value than that of the rods. In the Cu-Pd-Ag alloy wire, the nanolamellar structure of the matrix was revealed to contribute to the hardening of the wire.

Preparation and Tribological Properties of Surface-Coated Nano-Copper Additives

2008 ◽  
Vol 373-374 ◽  
pp. 580-584 ◽  
Author(s):  
Yi Xu ◽  
He Long Yu ◽  
Bin Shi Xu ◽  
Xiao Li Wang ◽  
Qian Liu
Keyword(s):  
Electron Microscope ◽  
Tribological Properties ◽  
Protective Film ◽  
Cu Nanoparticles ◽  
Transmission Electron ◽  
Load Carrying ◽  
Modification Technique ◽  
Average Size ◽  
Worn Surface ◽  
Worn Surfaces

In the present work, surface-coated Cu nanoparticles with FCC structure and an average size of 40 nm were prepared by reducing reaction and surface modification technique. The morphology and phase structure of the nano-copper were characterized by transmission electron microscope (TEM). The ball-on-disc tester and ring-on-block tester were performed to study the tribological properties of surface-coated Cu nanoparticles as oil additive. The tests were carried out under the lubrication of 50CC oil alone and oil containing surface-coated nano-copper additives. The morphologies and elementary distributions of the worn surfaces were analyzed by scanning electron microscope (SEM) and energy dispersive spectrometry (EDS), respectively. Results indicate that surface-coated nano-copper additives can significantly improve the wear resistance and load-carrying abilities of 50CC oil, as well as reduce friction coefficient. A soft copper protective film is formed on the worn surface lubricated with oil containing nano-copper additives, which separates the worn surfaces, avoids their direct contact and reduces friction and adhesive wear. Besides, the grooves and small valleys on the worn surfaces are found to be partly filled and repaired by nano-copper, as makes the worn surface repaired and smoother.

scholarly journals Evolution in Microstructure and Mechanical Properties of Inconel 783 Alloy Bolts after Long Term High-Temperature Aging at 700 °C

Metals ◽  
2020 ◽  
Vol 10 (11) ◽  
pp. 1440 ◽  
Author(s):  
Peng Duan ◽  
Zongde Liu ◽  
Shuchao Gu ◽  
Song Wang
Keyword(s):  
Mechanical Properties ◽  
Electron Microscope ◽  
Aging Time ◽  
Aging Temperature ◽  
Testing Machine ◽  
Impact Testing ◽  
Rapid Decline ◽  
Β Phase ◽  
Microstructure And Mechanical Properties ◽  
Orientation Distributions

This paper described systematically the changes in microstructure and mechanical properties of Inconel 783 alloy after a considerably long time (equivalently 55,000 h, about 76.4 months) of thermal exposure. Based on the Inconel 783 alloy bolts of an intermediate pressure main stop valve used in a 1000 MW ultra-supercritical unit, the evolution of microstructures and mechanical properties were studied after 700 °C aging temperature with different aging times (1000 h, 3000 h and 20,000 h, corresponding to about 1.4 months, 4.2 months and 27.8 months, respectively), using an optical microscope (OM), scanning electron microscope (SEM), transmission electron microscope (TEM) and X-ray diffractometer (XRD), a universal tensile testing machine and impact testing machine. The results indicated that the bolts aged for 1000 h in two temperatures, showing the second needle β phase, of which the quantity and size obviously increased with aging time. Meanwhile, the characteristics in quantity and shape of the primary β phase changed obviously with the aging time, which transformed to strip the Ni5Al3 and Laves-Nb-rich brittle phase in the matrix after aging for 20,000 h. The size of the γ’ phase grew bigger with aging time, and orientation distributions have been observed obviously at 3000 h aging in 700 °C. Compared with the 650 °C aging temperature, the coarsening of γ’ precipitates and second needle β, the orientation distributions of γ’ were more obvious at the 700 °C aging temperature with aging time, which resulted in the rapid decline in yield strength and tensile strength and obvious increase in the brittleness for Inconel 783 alloy bolts.

Microstructural Evolution and Stress Relaxation in Sputtered Tungsten Films

1993 ◽  
Vol 318 ◽  
Author(s):  
F. M. Ross ◽  
R. R. Kola ◽  
R. Hull ◽  
J. C. Bean
Keyword(s):  
Electron Microscope ◽  
Stress Relaxation ◽  
Microstructural Evolution ◽  
Transmission Electron Microscope ◽  
Specimen Geometry ◽  
Β Phase ◽  
Transmission Electron ◽  
The Relationship

ABSTRACTWe have investigated the relationship between microstructure and stress in very thin sputtered W films. We discuss features of the microstructure, in particular the presence of voids in compressively stressed films, in terms of the evolution of the structure from a metastable β-phase. By developing a novel specimen geometry for the transmission electron microscope (TEM), we present dynamic observations of the β-W→α-W transformation.

INFLUENCE OF CALCINED NANOCLAY ON FRACTURE TOUGHNESS OF NAOH-TREATED HEMP FABRIC REINFORCED CEMENT NANOCOMPOSITES

2015 ◽  
Vol 2 (1) ◽  
Author(s):  
A. Hakamy ◽  
F. U. A. Shaikh ◽  
I. M. Low
Keyword(s):  
Fracture Toughness ◽  
Cost Benefit Analysis ◽  
Microstructural Analysis ◽  
Cost Benefit ◽  
Pozzolanic Reaction ◽  
X Ray Diffraction ◽  
Transmission Electron ◽  
The Matrix ◽  
Reinforced Cement ◽  
Hemp Fabric

influence of calcined nanoclay (CNC) on the porosity and fracture toughness of treated hemp fabric-reinforced cement nanocomposites is presented in this paper. Characterisation of microstructure is investigated using Quantitative X-ray Diffraction Analysis (QXDA) and High Resolution Transmission Electron Microscopy (HRTEM). An optimum replacement of ordinary Portland cement with 1 wt% CNC is observed through reduced porosity and increased fracture toughness of treated hemp fabric-reinforced nanocomposite. The microstructural analysis indicates that the CNC affect not only as a filler to improve the microstructure, but also as the activator to support the pozzolanic reaction and thus improved the adhesion between the treated hemp fabric and the matrix. Cost-benefit analysis indicates the benefit of such cement eco-nanocomposites to develop new environmentally friendly nanomaterials and it can be used for various construction applications such as, ceilings and roofs.

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