scholarly journals Thermal Conductivity of Cu-Cr-Zr-Ti Alloy in the Temperature Range of 300–873 K

2012 ◽  
Vol 2012 ◽  
pp. 1-4 ◽  
Author(s):  
S. Chenna Krishna ◽  
N. Supriya ◽  
Abhay K. Jha ◽  
Bhanu Pant ◽  
S. C. Sharma ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Room Temperature ◽  
Ofhc Copper ◽  
Ti Alloy ◽  
Phonon Thermal Conductivity ◽  
Temperature Range ◽  
Transmission Electron

In the present investigation, thermal conductivity of Cu-Cr-Zr-Ti alloy was determined as the product of the specific heat (), thermal diffusivity (), and density () in the temperature range of 300–873 K. The experimental results showed that the thermal conductivity of the alloy increased with increase in temperature up to 873 K and the data was accurately modeled by a linear equation. For comparison, thermal conductivity was also evaluated for OFHC copper in the same temperature range. The results obtained were discussed using electrical conductivity and hardness measurements made at room temperature. Transmission electron microscopy (TEM) was done to understand the microstructural changes occurring in the sample after the test. Wiedemann-Franz-Lorenz law was employed for calculating electronic and phonon thermal conductivity using electrical conductivity. On the basis of studies conducted it was deduced that in situ aging may be one of the reasons for the increase in thermal conductivity with temperature for Cu-Cr-Zr-Ti alloy.

scholarly journals In situ environmental HRTEM discloses low temperature carbon soot oxidation by ceria–zirconia at the nanoscale

2019 ◽  
Vol 55 (27) ◽  
pp. 3876-3878 ◽  
Author(s):  
Eleonora Aneggi ◽  
Jordi Llorca ◽  
Alessandro Trovarelli ◽  
Mimoun Aouine ◽  
Philippe Vernoux
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Low Temperature ◽  
Room Temperature ◽  
Soot Oxidation ◽  
Environmental Transmission ◽  
Transmission Electron ◽  
Carbon Soot ◽  
Environmental Transmission Electron Microscopy

In situ environmental transmission electron microscopy discloses room temperature carbon soot oxidation by ceria–zirconia at the nanoscale.

Effect of Morphology on the Mobility of Nanosized Liquid Pb Inclusions in Solid Al

2007 ◽  
Vol 264 ◽  
pp. 55-62 ◽  
Author(s):  
S.I. Prokofjev ◽  
V.M. Zhilin ◽  
E. Johnson ◽  
U. Dahmen
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Wide Temperature Range ◽  
Diffusion Coefficients ◽  
Temperature Range ◽  
Transmission Electron ◽  
Thin Aluminum

Diffusion of nanosized liquid Pb inclusions attached to dislocations in thin aluminum foils was investigated in a wide temperature range using in-situ transmission electron microscopy. Trajectories of motion of the inclusions along the dislocations were used to determine their diffusion coefficients. The temperature and size dependences of diffusion coefficients of the inclusions were obtained. They indicate that (i) studied inclusions hold {111} facets on their surface in the studied temperature range; (ii) the mobility of the inclusions is controlled by step nucleation at the {111} facets.

Investigation of Ti3SiC2 MAX Phase Formation onto N-Type 4H-SiC

2012 ◽  
Vol 717-720 ◽  
pp. 845-848 ◽  
Author(s):  
Alexia Drevin-Bazin ◽  
Jean François Barbot ◽  
Thierry Cabioc’h ◽  
Marie France Beaufort
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
High Vacuum ◽  
Max Phase ◽  
Vacuum System ◽  
X Ray Diffraction ◽  
X Ray ◽  
Annealing Temperatures ◽  
Transmission Electron

In this study, investigations on MAX phase Ti3SiC2 formation to n-type 4H-SiC substrates and its ohmic-behaved are reported. Ti-Al layers were deposited onto SiC substrates at room temperature by magnetron sputtering in high vacuum system. Thermal annealing at 1000°C in Ar atmosphere were performed to allow interdiffusion processes. X-ray diffraction and High Resolution Transmission Electron Microscopy reveal that a Ti3SiC2 contact, in perfect epitaxy with 4H-SiC substrate, is so-obtained. In situ annealing experiment underlines the evolution of Ti-Al contact microstructure versus temperature. The evolution of contact system from Schottky to Ohmic behaved is observed by I-V measurements for annealing temperatures larger than 700°C.

Solid-State Reactions in Fe/Si Multilayer Nanofilms

2014 ◽  
Vol 215 ◽  
pp. 144-149 ◽  
Author(s):  
Sergey M. Zharkov ◽  
Roman R. Altunin ◽  
Evgeny T. Moiseenko ◽  
Galina M. Zeer ◽  
Sergey N. Varnakov ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Solid State ◽  
Electron Diffraction ◽  
Solid State Reaction ◽  
Room Temperature ◽  
Solid State Reactions ◽  
Transmission Electron ◽  
Reaction Processes

Solid-state reaction processes in Fe/Si multilayer nanofilms have been studied in situ by the methods of transmission electron microscopy and electron diffraction in the process of heating from room temperature up to 900ºС at a heating rate of 8-10ºС/min. The solid-state reaction between the nanolayers of iron and silicon has been established to begin at 350-450ºС increasing with the thickness of the iron layer.

Raising the Thermoelectric Performance of Fe3CoSb12 Skutterudites via Nd Filling and In-Situ Nanostructuring

2016 ◽  
Vol 16 (4) ◽  
pp. 3841-3847 ◽  
Author(s):  
Lijie Guo ◽  
Zhengwei Cai ◽  
Xiaolong Xu ◽  
Kunling Peng ◽  
Guiwen Wang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Figure Of Merit ◽  
Room Temperature ◽  
Thermoelectric Performance ◽  
Large Reduction ◽  
Dimensionless Figure Of Merit ◽  
Plasma Sintering ◽  
Spark Plasma

p-type skutterudites NdxFe3CoSb12 with x equaling 0.8, 0.85, 0.9, 0.95, 1.0 have been synthesized by solid state reaction followed by spark plasma sintering. The influence of Nd filling on electrical and thermal transport properties has been investigated in the Nd-filled skutterudite compounds in the temperature range from room temperature to 800 K. It was found that the Seebeck coefficient is drastically enhanced via filling Nd in p-Type skutterudites as well as the corresponding power factor although electrical conductivity is reduced. In addition, a large reduction in thermal conductivity is achieved by Nd fillers through rattling effect along with the In-Situ nanostructured precipitate through scattering phonons with much wider frequency. These concomitant effects result in an enhanced thermoelectric performance with the dimensionless figure of merit ZT. These observations demonstrate an exciting scientific opportunity to raise the figure-of-merit of p-type skutterudites.

Microsture and Properties of a Cu-Cr-Zr-Fe-Ti Alloy

2015 ◽  
Vol 723 ◽  
pp. 556-560
Author(s):  
Fu Xiang Huang
Keyword(s):  
Electron Microscopy ◽  
Electrical Conductivity ◽  
Transmission Electron Microscopy ◽  
Age Hardening ◽  
Peak Hardness ◽  
Ti Alloy ◽  
Hardening Behavior ◽  
Transmission Electron ◽  
Zn Alloys ◽  
Scanning Electron

The effect of 0.45 wt. % Fe and 0.2 wt. % Ti additions on the age hardening behavior of Cu-Cr-Zr-Zn alloys has been investigated with respect to hardness, electrical conductivity and microstructure. It was showed that the addition of Fe /Ti to Cu-Cr-Zr-Zn alloys enhance strength and hardness, but decrease the electrical conductivity, and increase the aging temperature and time for attaining peak hardness. The scanning electron microscope (SEM) and transmission electron microscopy (TEM) results showed that there are four types of phases in the alloy, Cu-matrix, Cr-rich, (Cu,Zr)-rich and (Fe,Ti)-rich phases.

Martensitic Nucleation in Small ZrO2 Particles

1985 ◽  
Vol 57 ◽  
Author(s):  
I-Wei Chen ◽  
Yi-Hung Chiao
Keyword(s):  
Thin Film ◽  
Electron Microscopy ◽  
Room Temperature ◽  
Equilibrium Temperature ◽  
Dislocation Loops ◽  
Spontaneous Transformation ◽  
Transmission Electron ◽  
Free Particles ◽  
Martensitic Nucleation

AbstractSmall ZrO2 particles were studied by in-situ transmission electron microscopy and the types of events which led to martensitic nucleation were recorded. These metastable particles were single crystals of several hundred nanometers size and were supported on a carbon thin film but were otherwise free from any constraint. At room temperature, they are more than 1200°C below the equilibrium temperature. After dislocation loops were injected in-situ into the originally defect-free particles, a critical loop size was found beyond which the particle transformed spontaneously. It was also observed that Hertzian contacts between two particles led to martensitic nucleation and spontaneous transformation. These results were satisfactorily rationalized by ab-initio theoretical analysis.

scholarly journals Microstructures of Three In-Situ Reinforcements and the Effect on the Tensile Strengths of an Al-Si-Cu-Mg-Ni Alloy

2018 ◽  
Vol 8 (9) ◽  
pp. 1523 ◽  
Author(s):  
Lusha Tian ◽  
Yongchun Guo ◽  
Jianping Li ◽  
Feng Xia ◽  
Minxian Liang ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Room Temperature ◽  
X Ray Diffraction ◽  
Simultaneous Formation ◽  
X Ray ◽  
Transmission Electron ◽  
Ni Alloy ◽  
Al3ti Phase ◽  
Scanning Electron

In the present paper, the microstructures of three kinds of in-situ reinforcements Al-Ti-C, Al-Ti-B, and Al-Ti-B-C-Ce were deeply investigated using a combination of scanning electron microscopy, X-ray diffraction spectroscopy, and transmission electron microscopy. The effect of in-situ reinforcements on the room temperature and elevated temperature (350 °C) tensile strengths of Al-13Si-4Cu-1Mg-2Ni alloy were analyzed. It is found that doping with trace amounts of B and Ce, the size of the Al3Ti phase in the in-situ reinforced alloy changed from 80 µm (un-reinforced) to about 10 µm, with the simultaneous formation of the AlTiCe phase. The Al-Ti-B-C-Ce reinforcement which is rapid solidified, was more effective and superior to enhance the tensile strengths of the Al-13Si-4Cu-1Mg-2Ni alloy, both at room and high temperatures than those of addition other reinforcements. The room temperature (RT) strength increased by 19.0%, and the 350 °C-strength increased by 18.4%.

Visualization of film-forming polymer particles with a liquid cell technique in a transmission electron microscope

The Analyst ◽  
2015 ◽  
Vol 140 (18) ◽  
pp. 6330-6334 ◽  
Author(s):  
Lili Liu ◽  
Yi Liu ◽  
Wenjun Wu ◽  
Christopher. M. Miller ◽  
Elizabeth C. Dickey
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Room Temperature ◽  
Staining Technique ◽  
Polymer Particles ◽  
Microscopy Technique ◽  
Transmission Electron ◽  
Film Forming ◽  
Liquid Cell

Liquid cell transmission electron microscopy technique provides the opportunity to image room-temperature film-forming polymer particles in solution. Together with staining technique, it can also be used as a tool to characterize the internal structure of polymer particles in situ.

Deuterium Interactions with Ion-Implanted Oxygen in Cu and Au

1988 ◽  
Vol 128 ◽  
Author(s):  
S. M. Myers ◽  
W. A. Swansiger ◽  
D. M. Follstaedt
Keyword(s):  
Electron Microscopy ◽  
Transmission Electron Microscopy ◽  
Ion Implantation ◽  
Nuclear Reaction ◽  
Room Temperature ◽  
Phase Changes ◽  
Nuclear Reaction Analysis ◽  
Temperature Range ◽  
Transmission Electron ◽  
First Time

ABSTRACTThe interactions of deuterium (D) with oxygen in Cu and Au were examined using ion implantation, nuclear-reaction analysis, and transmission electron microscopy. In Cu, the reduction of Cu2O precipitates by D to produce D20 was shown to occur readily down to room temperature, at a rate limited by the transport of D to the oxides. The reverse process of D2O dissociation was characterized for the first time below the temperature range of steam blistering. The evolution of the Cu(D)-Cu2O-D2O system was shown to be predicted by a newly extended transport formalism encompassing phase changes, trapping, diffusion, and surface release. In Au, buried 0 sinks were used to measure the permeability of D at 573 and 373 K, thereby extending the range of measured permeabilities downward by about six orders or magnitude.

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