The Experts below are selected from a list of 17469 Experts worldwide ranked by ideXlab platform
Yu Qiao - One of the best experts on this subject based on the ideXlab platform.
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the dependence of Infiltration Pressure and volume in zeolite y on potassium chloride concentration
Smart Materials and Structures, 2009Co-Authors: Aijie Han, Taewan Kim, Venkata K Punyamurtula, Yu QiaoAbstract:In a previous work we developed a volume-memory liquid that can expand or shrink significantly as the temperature varies. The working mechanism is based on the thermally induced Infiltration and defiltration of an electrolyte solution in the nanopores. In the current study, we investigate the influence of electrolyte concentration on the Infiltration behavior, as well as its dependence on temperature. The testing data show that, as the electrolyte concentration varies, the effective interfacial tension changes rapidly. This phenomenon can be attributed to the amplification effect of nanopore surfaces on the solid–liquid interaction. It provides a scientific basis for developing smart liquids for various temperature and Pressure ranges.
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Infiltration behaviour of water in a carbon nanotube under external Pressure
Philosophical Magazine Letters, 2008Co-Authors: Guoxin Cao, Yu Qiao, Qulan Zhou, Xi ChenAbstract:The wetting behaviour and associated Pressure effect of water in single-walled carbon nanotubes (SWCNTs) are investigated through molecular dynamics (MD) simulations. It is found that water molecules can enter SWCNTs via surface diffusion, and the effective Infiltration rate increases with Pressure. The effect of Pressure on Infiltration rate is highly non-linear, exhibiting characteristics of both hydrophilic and hydrophobic surfaces. There exists a nominal Infiltration Pressure that is dependent on the SWCNT size, above which the water flux is significantly increased.
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controlling Infiltration Pressure of a nanoporous silica gel via surface treatment
Chemistry Letters, 2007Co-Authors: Aijie Han, Yu QiaoAbstract:Energy absorption behaviors of a surface-treated nanoporous silica gel are investigated through a Pressure-induced Infiltration experiment. The results show that the Infiltration Pressure is domina...
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Infiltration Pressure of a nanoporous liquid spring modified by an electrolyte
Journal of Materials Research, 2007Co-Authors: Aijie Han, Yu QiaoAbstract:In a hydrophobic zeolite, the Infiltration and defiltration of water can be controlled by adjusting external Pressure, and therefore the system behaves as a “liquid spring.” Since the hysteresis of sorption isotherm is negligible and the working Pressure is thermally controllable, volume memory devices can be developed based on this phenomenon. With the addition of sodium chloride, both Infiltration and defiltration Pressures increase, which should be attributed to the cation exchange. The temperature sensitivity of the system increases with the electrolyte concentration, beneficial to improving the output energy density.
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thermal effects on Pressure induced Infiltration of a nanoporous system
Philosophical Magazine Letters, 2005Co-Authors: X Kong, Yu QiaoAbstract:Thermal effects on the energy absorption efficiency of a system consisting of hydrophobic mesoporous silica particles immersed in water have been investigated. As the temperature increases, although the Infiltration Pressure decreases only slightly and the accessible pore volume remains nearly constant, the system recoverability can be significantly improved, primarily due to an increase in outflow Pressure. The sequence of changing Pressure and temperature has little influence on the system performance.
Andreas Mortensen - One of the best experts on this subject based on the ideXlab platform.
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influence of the wetting angle on capillary forces in Pressure Infiltration
Acta Materialia, 2015Co-Authors: Alain Leger, L Weber, Andreas MortensenAbstract:Abstract This work probes the influence of wetting on Pressure Infiltration. Pressure/saturation curves for the Infiltration of packed F1000 angular alumina particle preforms by liquid Cu–Al and Sn–Al alloys are measured using an instrumented high-temperature Pressure Infiltration apparatus. These are ceramic–metal systems in which the contact angle is documented to vary significantly with alloying, from non-wetting to wetting conditions. We show that adding Al to Sn or to Cu modifies the early percolation-dominated phases of Infiltration and also the later, pore geometry dominated, phase of the Infiltration process. Changes in contact angle brought by alloying cause the saturation/Pressure curves to shift, yet for all systems of this work the curves remain entirely in the range of positive Pressures, despite a transition to contact angles below 90°. Combining measured Pressures for Infiltration at fixed saturation with relevant sessile drop experiment data from the literature shows that for, the range of conditions explored here, the Infiltration Pressures required are proportional, not to the work of immersion, but to a linear function thereof. This result agrees qualitatively with prior work in the literature on the Infiltration of non-metallic liquids in porous media, and provides a master curve by means of which saturation curves and sessile drop data can be reconciled for this particular packed ceramic particle preform.
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Influence of the Infiltration Pressure on the structure and properties of replicated aluminium foams
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2006Co-Authors: J. F. Despois, Ariane Marmottant, Luc Salvo, Andreas MortensenAbstract:Replicated pure aluminium foams are produced by infiltrating identical preforms of 400 μm NaCl particles packed to 75% relative density, varying the metal Infiltration Pressure to vary the metal foam relative density between 15% and 25%. As the Infiltration Pressure is increased, small finger-like protrusions appear on the foam struts; these lower the foam permeability to fluid flow. The compressive mechanical properties of the foams, namely Young's modulus and yield stress, increase steadily with increasing relative density. Taken together, the data indicate that it is the gradual ingress of metal into narrow gaps between neighbouring particles that governs the evolution of foam properties with increasing Infiltration Pressure.
E Louis - One of the best experts on this subject based on the ideXlab platform.
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effects of Infiltration Pressure on mechanical properties of al 12si graphite composites for piston engines
Composites Part B-engineering, 2016Co-Authors: J Narciso, J M Molina, Alejandro Rodriguez, F Rodriguezreinoso, E LouisAbstract:Abstract In this work results for the flexural strength and the thermal properties of interpenetrated graphite preforms infiltrated with Al-12wt%Si are discussed and compared to those for packed graphite particles. To make this comparison relevant, graphite particles of four sizes in the range 15–124 μm, were obtained by grinding the graphite preform. Effects of the Pressure applied to infiltrate the liquid alloy on composite properties were investigated. In spite of the largely different reinforcement volume fractions (90% in volume in the preform and around 50% in particle compacts) most properties are similar. Only the Coefficient of Thermal Expansion is 50% smaller in the preform composites. Thermal conductivity of the preform composites (slightly below 100 W/m K), may be increased by reducing the graphite content, alloying, or increasing the Infiltration Pressure. The strength of particle composites follows Griffith criterion if the defect size is identified with the particle diameter. On the other hand, the composites strength remains increasing up to unusually high values of the Infiltration Pressure. This is consistent with the drainage curves measured in this work. Mg and Ti additions are those that produce the most significant improvements in performance. Although extensive development work remains to be done, it may be concluded that both mechanical and thermal properties make these materials suitable for the fabrication of piston engines.
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the effect of porosity on the thermal conductivity of al 12 wt si sic composites
Scripta Materialia, 2009Co-Authors: J M Molina, J Narciso, R Prieto, E LouisAbstract:The effect of porosity (up to 13%) on the thermal conductivity of composites obtained by Infiltration of Al–12 wt.% Si alloy into SiC particulate preforms has been determined. The thermal conductivity of these composites gradually increases with the applied Infiltration Pressure given the inherent reduction in porosity. A simple application of the Hasselman–Johnson model in a two-step procedure (which accounts for the presence of both SiC particles and voids randomly dispersed in a metallic matrix) offers a good approximation of the experimental results.
Makoto Yoshida - One of the best experts on this subject based on the ideXlab platform.
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fabrication process of carbon nanotube light metal matrix composites by squeeze casting
Materials Science and Engineering A-structural Materials Properties Microstructure and Processing, 2008Co-Authors: Hisao Uozumi, K Kobayashi, Kota Nakanishi, Tadashi Matsunaga, Kenji Shinozaki, Hiroki Sakamoto, Takayuki Tsukada, Chitoshi Masuda, Makoto YoshidaAbstract:Multi-walled carbon nanotubes (MWCNTs) should be attractive for the reinforcement of metal-matrix composites, because of their high strength, high modulus and high thermal conductivity. However, the fiber diameter of MWCNTs is hundreds of times smaller than that of carbon fiber. This causes difficulty in Infiltration into the MWCNT preform. Moreover, the threshold Pressure which was applied to the preform will cause preform deformation. Therefore, knowledge of preform compressive properties which are the buckling strength and elastic modulus are necessary to fabricate the composites. In this study, at first, wettability of the basal plane of graphite by molten aluminum or magnesium was measured using the sessile drop method. Moreover, trial fabrication of MWCNT-reinforced aluminum or magnesium alloy composites was carried out by squeeze casting. As a result, these composites were fully infiltrated. An order-of-magnitude agreement was found between the estimated threshold Pressure and the applied Infiltration Pressure to the MWCNT preform.
Weiyi Lu - One of the best experts on this subject based on the ideXlab platform.
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enhanced energy mitigation of thin walled tube filled with liquid nanofoam under dynamic impact
Composites Part B-engineering, 2020Co-Authors: Mingzhe Li, Saeed David Barbat, Ridha Baccouche, Jamel E Belwafa, Weiyi LuAbstract:Abstract Due to the intimate contact between the fluid-like liquid nanofoam (LN) filler and the tube wall, the filler-tube wall interaction in LN-filled tube (LNFT) is enhanced, leading to a much-improved performance of the composite structure. However, a comprehensive understanding of the energy mitigation performance and the underlying working mechanism of LNFT is still lacking. This study aims to explore the crushing behavior of LNFT subjected to quasi-static compression and dynamic impact and reveal the working mechanism of LNFT at different strain rates and the selection criteria for LN filler and tube wall material. A series of quasi-static compression tests are conducted on LNFTs with various LN fillers. The strengthening coefficient of LNFTs is larger than 3.5. Micro-CT images show that the LN-tube interaction improves the performance of LNFT through extended plastic deformation of the tube wall. Under dynamic impacts, the energy absorption capacity of LNFT shows 54% increase compared to that under quasi-static tests, leading to a remarkable strengthening coefficient of 8.0. The strain rate effect is due to the different energy mitigation mechanisms of the LN-filler, i.e. energy dissipation at lower strain rate and energy capture at higher strain rate. To optimize the impact mitigation performance of LNFT, the most critical system parameters are the Infiltration Pressure and total pore volume of the LN-filler and the stiffness and ductility of the tube wall. These findings and research outcomes expedite the understanding of the impact mitigation mechanism of LNFT and provide design guidance for the LN-based composite structures.
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compressing liquid nanofoam systems liquid Infiltration or nanopore deformation
Nanoscale, 2018Co-Authors: Yue Zhang, Baoxing Xu, Mingzhe Li, Weiyi LuAbstract:Understanding the invasion of a liquid into porous structures is the foundation of the characterization of the porosity-related properties of materials and is also of fundamental importance in the design of porous solid–liquid enabled energy protection systems, yet whether solid pores deform has been unclear so far. Here, we present a competition mechanism between liquid Infiltration and cell wall buckling deformation by investigating a liquid nanofoam (LN) system subjected to quasi-static compression. The critical buckling stress of the cell wall and the Infiltration Pressure of liquid invasion into nanopores are studied and correlated through numerical simulation and experimental validation to reveal the quantitative relationship between nanopore deformation and liquid invasion. The analysis shows that liquid Infiltration occurs, independent of the axial buckling stress of the cell wall; in contrast, the nanopore collapses radially when the radial collapse Pressure is lower than the Pressure of liquid Infiltration, preventing the liquid invasion. Comprehensive molecular dynamics (MD) simulations are performed and demonstrate the deformation behavior of nanopores and cell wall–liquid interactions in a broad range. Pressure-induced compression experiments on a silica-based LN system are carried out and validate these theoretical and MD results.