Press forming of closed-cell porous aluminum of functionally graded porous aluminum consisting with open-cell structure and closed-cell structure

2019 ◽  
Vol 2019.27 (0) ◽  
pp. 405
Author(s):  
Mizuki ANDO ◽  
Yoshihiko HANGAI ◽  
Kenji AMAGAI ◽  
Ryohei NAGAHIRO ◽  
Masataka OHASHI ◽  
...  
Keyword(s):  
Cell Structure ◽  
Functionally Graded ◽  
Open Cell ◽  
Porous Aluminum ◽  
Press Forming ◽  
Closed Cell

scholarly journals Fabrication of Two-Layered Aluminum Foam with Closed-Cell and Open-Cell Structures and Shaping of Closed-Cell Layer by Press Forming Immediately after Foaming

Metals ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 140
Author(s):  
Yoshihiko Hangai ◽  
Mizuki Ando ◽  
Masataka Ohashi ◽  
Kenji Amagai
Keyword(s):  
Aluminum Alloy ◽  
Melting Point ◽  
Aluminum Foam ◽  
Cell Layer ◽  
Open Cell ◽  
Press Forming ◽  
Cell Structures ◽  
Closed Cell ◽  
The Press

Two-layered aluminum foam consisting of both closed and open cells is expected to improve the functionality of aluminum foam, because the cells have different morphologies and characteristics. In this study, press forming of the closed-cell layer of the two-layered aluminum foam immediately after foaming was performed to shape the closed-cell layer. By measuring the temperatures of the two layers during foaming, we found that it is necessary to use aluminum alloy with a higher melting point for the open-cell layer than that for the closed-cell layer to foam the closed-cell layer. In the press forming experiments, the closed-cell layer could be shaped by press forming while the shape of the open-cell layer was maintained.

Low-profile visualized intraluminal support Blue stenting within a Neuroform Atlas stent for a large wide-necked aneurysm: A case report and a bench-top experiment

2021 ◽  
pp. 197140092110269
Author(s):  
Tomoko Hayashi ◽  
Hiroyuki Ikeda ◽  
Ryota Ishibashi ◽  
Toshio Fujiwara ◽  
Ryosuke Kaneko ◽  
...  
Keyword(s):  
Case Report ◽  
Coil Embolization ◽  
Cell Design ◽  
Open Cell ◽  
Aneurysm Neck ◽  
Low Profile ◽  
Closed Cell ◽  
High Metal ◽  
Silicon Tube ◽  
Aneurysm Occlusion

Low-profile visualized intraluminal support deployment in an Enterprise has been reported; however, that in an Atlas has yet to be in detail. Enterprise has a closed-cell design, while Atlas has an open-cell design. We detail here a case of a large wide-necked aneurysm treated by coil embolization with low-profile visualized intraluminal support Blue deployment within a Neuroform Atlas and a bench-top experiment using a silicon tube to test low-profile visualized intraluminal support, Atlas, Enterprise, and their combinations. A better low-profile visualized intraluminal support expansion was achieved by simultaneously pushing the wire and the system within the Atlas placed at the aneurysm neck, which resulted in an increased metal coverage of the aneurysm neck and a shorter transition zone with low metal coverage at both ends of the aneurysm neck. This technique may enable a high metal coverage by low-profile visualized intraluminal support expansion without restriction by the Atlas and contribute to aneurysm occlusion by increasing the flow-diverting effect.

Virtual enclosure model for thermal radiation extinction inside porous materials with closed cell structure

2015 ◽  
Vol 87 ◽  
pp. 79-91 ◽  
Author(s):  
Ari Seppälä ◽  
Olli Vartia ◽  
Pyry Seppälä ◽  
Kari Saari ◽  
Tuula Noponen ◽  
...  
Keyword(s):  
Thermal Radiation ◽  
Porous Materials ◽  
Cell Structure ◽  
Closed Cell ◽  
Radiation Extinction

Porous Bioceramics (Open Cell Foams) Expanded in Vacuum

2006 ◽  
Vol 309-311 ◽  
pp. 1023-1026
Author(s):  
E.T. Uzumaki ◽  
C.S. Lambert
Keyword(s):  
Zirconium Oxide ◽  
Cell Structure ◽  
The Body ◽  
Carbon Coatings ◽  
Open Cell ◽  
Glass Foam ◽  
Open Cell Foams ◽  
Titanium Foam ◽  
Porous Bioceramics ◽  
Scanning Electron

In this study, porous bioceramics (titanium foam with diamond-like carbon coatings, glass foam and zirconium oxide foam) were produced using expansion in vacuum. The porosity, the pore size and pore morphology can be adjusted in agreement with the application. The different 3D structures were obtained by varying the parameters of the process. The microstructure and morphology of the porous materials were observed by scanning electron microscopy (SEM) and optical microscopy. The foam exhibit an open-cell structure with interconnected macropores, which provide the potential for tissue ingrowths and the transport of the body fluids.

scholarly journals Study of Physical Properties and Shock Absorption Abilities of Starch Polymer Foam as Cushioning Material for Packaging

2018 ◽  
Vol 225 ◽  
pp. 06010
Author(s):  
N. Amir ◽  
Mohamed Syakir Mohamed Hisham ◽  
Kamal Ariff Zainal Abidin
Keyword(s):  
Average Density ◽  
Curing Process ◽  
Polymer Foam ◽  
Shock Absorption ◽  
Open Cell ◽  
Lack Of Information ◽  
Closed Cell ◽  
Open Cell Foam ◽  
Cell Foam ◽  
Cushioning Material

Lack of information about the formulation and fabrication process of starch polymer foam and lack of study in the shock absorption ability of starch polymer foam were the reasons this research was executed. In this project starch polymer foam was produced to be used as cushioning material for packaging. Starch polymer foam were developed from starch, polyvinyl alcohol (PVA), urea, citric acid, and deionised water. Water amount with drying and curing process were the variables manipulated to produce the best starch polymer foam. It was determined then, that the optimized ratio of starch:PVA:citric acid was 1:1:4. The amount of water used was 10 ml/gram of starch/PVA weight. The suitable foaming mixing was done at a speed of 1500 rpm for 40 minutes. Drying process was done at 70°C for 24 hours, followed by curing process at 100°C for 1 hour to produce closed-cell foam. While for the open-cell foam, the foam was dried and cured at 100ºC for 6 hours. The open-cell and closed-cell foams produced were cut to 6 cm height x 6 cm width x 0.5 cm thick. The average density was calculated and then the foams were subjected to weight drop destructive test. The test was done by placing a foam on top of a piece of mirror, and a weight is dropped onto the foam, with increasing height until the mirror break. Three weights were used with mass of 50 g, 100 g and 200 g. The starch foams were compared to polyurethane and polystyrene foams in terms of the minimum height that can cause the mirror to break. The results showed that starch closed-cell foam absorbed the highest impact energy followed by polystyrene foam, starch open-cell foam and polyurethane foam.

Open-Cell Foam Metal Production and Characterization by Aluminum Solid Mold Investment Casting

2019 ◽  
Author(s):  
Kerem Altug Guler
Keyword(s):  
Investment Casting ◽  
Replication Process ◽  
Open Cell ◽  
Metal Fabrication ◽  
Cell Structures ◽  
Closed Cell ◽  
Small Complex ◽  
Open Cell Foam ◽  
Foam Metal ◽  
Cell Foam

Foam metals can be categorized in two basic classes: open-cell and closed-cell structures, which both have different numerous unique properties. Up to the present, several production processes have been developed for each class. Investment casting is known as a replication process for open-cell foam metal fabrication. Solid mold, which can be evaluated as a subtechnique of the investment casting, is specialized especially for small complex shapes with ultrathin sections. This work is a presentation of aluminum open-cell foam production with solid mold investment casting using two different kinds of patterns. The first one is “burnable,” in which liquid metal directly fills the shape of pattern and the second is “leachable,” in which metal takes the form of intergranular network shape of porous salt preforms.

scholarly journals Microstructural and Chemical Analysis of Polyurethane and Polyisocyanurate Foam Insulations

2021 ◽  
Author(s):  
Umberto Berardi
Keyword(s):  
Thermal Conductivity ◽  
Thermal Performance ◽  
Cell Structure ◽  
Polymer Degradation ◽  
Chemical Characterization ◽  
Aging Behavior ◽  
Blowing Agent ◽  
Closed Cell ◽  
Physical Attributes ◽  
Cell Foam

For some closed cell foam insulation products, the thermal conductivity increases at low temperatures, contrary to single thermal resistance values provided by manufacturers. This phenomenon has been demonstrated in various polyurethane and polyisocyanurate insulations. The reduction in thermal performance has been attributed to the diffusion of air and blowing agent through the foam and to the condensation of blowing agent. Aging processes such as freeze-thaw cycling, moisture accumulation, and polymer degradation further increase thermal conductivity. The initial cell structure plays a role in dictating the thermal performance. To further understand the loss of thermal performance in closed cell foams, microstructure and chemical characterization was performed in this study. The aging behavior of foam insulations was analyzed by imaging foams with SEM and by measuring foam. Changes in the polymer physical attributes were identified and compared to increases in thermal conductivity. This project also used gas chromatography and quantified changes in pentane concentration in polyisocyanurate foams that have undergone aging

scholarly journals Contrasting characteristics of open- and closed- cellular stratocumulus cloud in the Eastern North Atlantic

2021 ◽  
Author(s):  
Michael P. Jensen ◽  
Virendra P. Ghate ◽  
Dié Wang ◽  
Diana K. Apoznanski ◽  
Mary J. Bartholomew ◽  
...  
Keyword(s):  
Boundary Layer ◽  
North Atlantic ◽  
Large Scale ◽  
Marine Boundary Layer ◽  
Open Cell ◽  
Cold Air ◽  
Closed Cell ◽  
Boundary Layer Cloud ◽  
Eastern North Atlantic ◽  
Layer Cloud

Abstract. Extensive regions of marine boundary layer cloud impact the radiative balance through their significant shortwave albedo while having little impact on outgoing longwave radiation. Despite this importance, these cloud systems remain poorly represented in large-scale models due to difficulty in representing the processes that drive their lifecycle and coverage. In particular, the mesoscale organization, and cellular structure of marine boundary clouds has important implications for the subsequent cloud feedbacks. In this study, we use long-term (2013–2018) observations from the Atmospheric Radiation Measurement (ARM) Facility's Eastern North Atlantic (ENA) site on Graciosa Island, Azores, Portugal to identify cloud cases with open- or closed-cellular organization. More than 500 hours of each organization type are identified. The ARM observations are combined with reanalysis and satellite products to quantify the cloud, precipitation, aerosol, thermodynamic and large-scale synoptic characteristics associated with these cloud types. Our analysis shows that both cloud organization populations occur during similar sea surface temperature conditions, but the open-cell cases are distinguished by stronger cold-air advection and large-scale subsidence compared to the closed-cell cases, consistent with their formation during cold-air outbreaks. We also find that the open-cell cases were associated with deeper boundary layers, stronger low-level winds, and higher-rain rates compared to their closed-cell counterparts. Finally, raindrops with diameters larger than one millimeter were routinely recorded at the surface during both populations, with a higher number of large drops during the open-cellular cases. The similarities and differences noted herein provide important insights into the environmental and cloud characteristics during varying marine boundary layer cloud mesoscale organization and will be useful for the evaluation of model simulations for ENA marine clouds.

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