scholarly journals Transitions and Geometric Evolution of Cu309 Nanocluster during Slow Cooling Process

Crystals ◽  
2018 ◽  
Vol 8 (5) ◽  
pp. 231
Author(s):  
Pengfei Ji ◽  
Yi Zhao ◽  
Mingli Wan ◽  
Jinna He ◽  
Mingli Tian ◽  
...  
Keyword(s):  
Cooling Process ◽  
Slow Cooling ◽  
Geometric Evolution

Rapid microwave synthesis of Cu2Se thermoelectric material with high conductivity

2021 ◽  
pp. 2151005
Author(s):  
Yongpeng Wang ◽  
Wenying Wang ◽  
Haoyu Zhao ◽  
Lin Bo ◽  
Lei Wang ◽  
...  
Keyword(s):  
Thermal Conductivity ◽  
Electrical Conductivity ◽  
Grain Growth ◽  
Microwave Synthesis ◽  
Annealing Process ◽  
High Electrical Conductivity ◽  
Cooling Process ◽  
Slow Cooling ◽  
Te Material ◽  
Hot Pressing Sintering

In this study, the dense bulk Cu2Se thermoelectric (TE) materials were prepared by microwave melting and hot pressing sintering. The effects of different cooling processes on the microstructure and TE properties of Cu2Se were investigated. The results showed that the Cu2Se TE material prepared by microwave synthesis had high electrical conductivity, which was about 105 S⋅ m[Formula: see text]. The annealing process can lead to grain growth of Cu2Se and the formation of micropores in the Cu2Se, which deteriorated the thermal conductivity. The Cu2Se material prepared by the microwave melting and slow cooling process had the best TE performance, and the ZT value can reach 0.68 at 700 K.

Dielectric Properties of Epoxy/Anhydride System in Long-Term Storage

2017 ◽  
Vol 898 ◽  
pp. 2143-2146
Author(s):  
Chun Miao Han ◽  
Kang Peng ◽  
Liu Yang ◽  
Zhi Bin Zeng
Keyword(s):  
Dielectric Properties ◽  
Loss Angle ◽  
Cooling Process ◽  
Slow Cooling ◽  
Long Term Storage ◽  
Dielectric Loss Angle ◽  
Different Content ◽  
Curing Procedure ◽  
Term Storage

The change of dielectric properties of epoxy/anhydride systems during eleven months storing was investigated. Test systems were bisphenol-A epoxy cured by different content of methyl-hexahydrophthalic anhydride with a slow cooling process across Tg range included in their curing procedure to reduce residual stress. The results showed all the systems’ dielectric constant and dielectric loss angle tangent had a trend of down then up. The highest decreasing amplitudes were about 4% and 10% respectively. Possible explanations for these phenomena were proposed, and then some preliminary investigations were carried out like DSC and IR.

Implementation of Glass Transition Physics in Glass Molding Simulation

2011 ◽  
Vol 325 ◽  
pp. 707-712 ◽  
Author(s):  
H.H. Ruan ◽  
Liang Chi Zhang
Keyword(s):  
Monte Carlo ◽  
Glass Transition ◽  
Optical Glass ◽  
Master Equations ◽  
Cooling Process ◽  
Slow Cooling ◽  
Potential Energy Landscape ◽  
The Monte Carlo Method ◽  
Element Simulation ◽  
Replication Quality

Glass transition is the most important factor in the thermo-forming of glass elements of precise geometries such as optical glass lenses. Among many attempts to model the physics of glass transition, the Master equations based on the potential energy landscape (PEL) appear to be apropos. In this study, we used Monte-Carlo approach to approximately solve the master equations and further implement the Monte-Carlo method in the finite element simulation. We used Selenium as an example since its PEL has been quantified. Through the FEM simulations, it is found that the geometrical replication quality is the best when the forming is performed at the viscosity around 105~106Pa×s, that the residual stress developed in the cooling process can be minimized in the slow cooling process or through post-annealing process after moulding.

Fabrication conditions and superconducting properties of Ag‐sheathed Bi‐Sr‐Ca‐Cu‐O tapes prepared by partial melting and slow cooling process

1993 ◽  
Vol 62 (17) ◽  
pp. 2131-2133 ◽  
Author(s):  
K. Nomura ◽  
M. Seido ◽  
H. Kitaguchi ◽  
H. Kumakura ◽  
K. Togano ◽  
...  
Keyword(s):  
Partial Melting ◽  
Superconducting Properties ◽  
Cooling Process ◽  
Slow Cooling

Effects of Electromagnetic Agitation on Crystal Growth during the Pure Aluminum Slow Cooling Process

2020 ◽  
Vol 993 ◽  
pp. 398-403
Author(s):  
Xiang Jie Wang ◽  
Fang Yu ◽  
Peng Wei Li ◽  
Wei Sun ◽  
Hong Juan Tan ◽  
...  
Keyword(s):  
Crystal Growth ◽  
Structure Refinement ◽  
Pure Aluminum ◽  
Low Frequency ◽  
Casting Process ◽  
Cooling Process ◽  
Continuous Casting Process ◽  
Slow Cooling ◽  
Fine Grain ◽  
Refinement Effect

Refining grains are important to obtain sound cast billets suitable for further processing. The structure refinement of low frequency electromagnetic field (LFEF) during the aluminum alloy semi-continuous casting process has been confirmed by many researchers. In this work, effects of the electromagnetic agitation on the crystal growth were investigated during the pure aluminum slow cooling process. The results showed that the grain refinement effect by electromagnetic agitation mainly occurred at the first half period of crystal growth. With increasing of applying LFEF treated time, the fine grain occupied the whole section of ingot, and the ratio of fine grain zone to the whole section was proportional to the treated time.

Effect of Homogenisation Parameters on Dissolution and Precipitation in Aluminium Alloy AA7150

2011 ◽  
Vol 693 ◽  
pp. 276-281 ◽  
Author(s):  
Li Juan Wang ◽  
Dao Kui Xu ◽  
Paul A. Rometsch ◽  
Sam X. Gao ◽  
Yong Zhang ◽  
...  
Keyword(s):  
Cooling Rate ◽  
Single Step ◽  
S Phase ◽  
Cooling Process ◽  
Controlled Cooling ◽  
Scanning Calorimetry ◽  
Slow Cooling ◽  
Eutectic Particles ◽  
Type Size ◽  
Thermal Stability Of

The thermal stability of constituent particles in both as-cast and homogenised alloy AA7150 has been investigated by means of scanning electron microscopy (SEM) and differential scanning calorimetry (DSC). The results indicate that the as-cast eutectic starts to melt at 474°C and that the melting onset temperatures of the η- and S-phase particles after homogenisation are 474°C and 484°C, respectively. Two types of homogenisation treatments were used to dissolve eutectic particles: a two-step homogenisation treatment (40 h at 465°C + 4 h at 480°C) can completely dissolve the η- and S-based constituents, whereas a significant amount of S-phase still exists after a single-step homogenisation treatment of 40 h at 465°C. After utilising the two-step homogenisation treatment to dissolve all the η- and S-based constituents without overheating, samples were cooled at different controlled cooling rates and analysed by SEM and DSC to understand the effect of cooling rate on the type, size, distribution and density of precipitates formed during the cooling process. Slow cooling was found to result in the precipitation of coarse η-phase particles, with both the amounts and sizes of these η-phase particles increasing with decreasing cooling rate.

Processing of High Current Density Yba2cu3ox Superconductors

1989 ◽  
Vol 169 ◽  
Author(s):  
V. Selvamanickam ◽  
K. Salama
Keyword(s):  
Current Density ◽  
Weak Link ◽  
High Current Density ◽  
Microstructural Analysis ◽  
Processing Parameters ◽  
Peritectic Temperature ◽  
High Current ◽  
Cooling Process ◽  
Slow Cooling ◽  
Different Temperatures

AbstractA liquid phase processing method has been developed to fabricate oriented grained YBa2Cu30x samples with high current density. The current density in these samples, however, is sensitive to the microstructure which is controlled by processing parameters. Cooling rate through the peritectic temperature is found to be the most crucial factor in controlling the extent of grain orientation and in turn the bulk current carrying capacity. The evolution of the microstructure during the slow cooling process is studied by quench experiments at different temperatures. From microstructural analysis, the suitable temperature profile for the slow cooling process is chosen. Current density measurements across grains show a Jc in excess of 104 A/cm2. This implies that the weak link behavior of grain boundaries in polycrystalline superconductors can be suppressed to a considerable extent.

scholarly journals Effects of Cooling Rates on Self-Assembling Structures of 12-Hydroxystearic Acid in an Ionic Liquid

2017 ◽  
Vol 2017 ◽  
pp. 1-8 ◽  
Author(s):  
Hiroyuki Takeno ◽  
Mai Kozuka
Keyword(s):  
Ionic Liquid ◽  
Ionic Conductivity ◽  
Sol Gel ◽  
Solution Temperature ◽  
Hydroxystearic Acid ◽  
Cooling Process ◽  
Slow Cooling ◽  
Cooling Rates ◽  
Self Assembling ◽  
Polymorphic Forms

We investigated effects of cooling rates on self-assembling structures and mechanical and electrochemical properties of 12-hydroxystearic acid (12-HSA) in an ionic liquid (IL), 1-allyl-3-butylimidazolium bis(trifluoromethanesulfonyl) imide ([ABIm][TFSI]). The mixture of 12-HSA with [ABIm][TFSI] had an upper critical solution temperature (UCST) above the sol-gel transition temperature, and the microstructure of the ionogel was significantly affected by cooling rates, where it was prepared. The twisted self-assembling structure was formed during a slow cooling process at a rate of 0.4°C/min, whereas spherical domains caused by the liquid-liquid phase separation and radiate fibrous structure were observed for the quenched gel. The real-time small-angle X-ray scattering (SAXS) measurements for the ionogel during a slow cooling process at a rate of 0.4°C/min presented three different (001) peaks arising from long spacings of 46.5, 42.4, and 39.7 Å, which were also observed for SAXS curves of a neat 12-HSA. These results suggest that three polymorphic forms of 12-HSA are formed in the IL. The polymorphic form significantly affected the mechanical properties of the ionogel, whereas it did not affect the ionic conductivity. The ionic conductivity of the ionogel was close to that of a neat [ABIm][TFSI] irrespective of the polymorphic forms of 12-HSA.

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