Modeling of an Electropolishing-Assisted Electroless Deposition Process for Microcellular Metal Foam Fabrication

2017 ◽  
Vol 139 (3) ◽  
Author(s):  
Wei Jiang ◽  
Russell Borduin ◽  
Hao Xin ◽  
Wei Li
Keyword(s):  
Pore Size ◽  
Process Model ◽  
Electroless Deposition ◽  
Metal Foam ◽  
Deposition Process ◽  
Metal Foams ◽  
Diffusion Limit ◽  
Ion Diffusion ◽  
Polymer Templates ◽  
Polymer Template

Metal foams can be fabricated through metallizing nonconductive polymer templates for better control of pore size, porosity, and interpore connectivity. However, the process suffers from a diffusion limit when the pore size is reduced to micro- and nanoscales. In this research, an electropolishing-assisted electroless deposition (EPAELD) process is developed to fabricate open-celled microcellular metal foams. To overcome the diffusion limit, a polishing current is applied in the electroless deposition process to remove metal on the surface of a polymer template, such that the ion-diffusion channels will remain open and the electroless deposition reaction continues deep inside the polymer template. In this paper, a process model of the proposed EPAELD technique is developed to understand the mechanism and to optimize the proposed process.

scholarly journals A Novel Economical Method of Determining the Geometric Characteristic of the Metal Foam Based on Image Analysis

Energies ◽  
2020 ◽  
Vol 13 (13) ◽  
pp. 3378
Author(s):  
Martin Beer ◽  
Marcela Taušová ◽  
Radim Rybár ◽  
Michal Kaľavský
Keyword(s):  
Image Analysis ◽  
High Resolution ◽  
Metal Foam ◽  
Geometric Characteristic ◽  
Deposition Process ◽  
Metal Foams ◽  
Image Capture ◽  
X Ray ◽  
Basic Characteristics ◽  
Energy Absorbers

The presented paper deals with the metal foams, which have a wide application potential ranging from power engineering, through catalysts to impact energy absorbers. The main aim of the paper is to propose an economical non-destructive method of determining the basic characteristics and dimensions using affordable devices. The basic principle of the proposed method lies in the image capture of metal foam and their subsequent analysis in image analysis software. An important element of the work is a comparison of results obtained by the proposed method with results obtained by high-resolution X-ray microtomography. The proposed method was evaluated in terms of measurement uncertainty and propagation of error in overall results. The use of the method is limited to the metal foams, characterized by an ordered structure, which are produced mainly by the electrophoretic deposition process. Based on the descriptive statistical analysis of results, it is possible to state, that the proposed method is in great agreement with accurate, but more expensive high-resolution X-ray microtomography.

Effects of Metal Foam Porosity, Pore Size, and Ligament Geometry on Fluid Flow

2018 ◽  
Vol 10 (4) ◽  
Author(s):  
Beshoy Morkos ◽  
Surya Venkata Sumanth Dochibhatla ◽  
Joshua D. Summers
Keyword(s):  
Fluid Flow ◽  
Pore Size ◽  
Metal Foam ◽  
Maximum Flow ◽  
Metal Foams ◽  
Design Parameters ◽  
Optimum Configuration ◽  
Multinomial Logit Regression ◽  
Thermal Energy Dissipation ◽  
Section Shape

This paper explores the effects of porosity, pore size, and ligament geometry in metal foams on its fluid flow capability. The motivation to understand this phenomenon stems from exploring the use of metal foams for thermal energy dissipation applications where both thermal convection and fluid flow are desired. The goal of this research is to identify the optimum configuration of metal foam design parameters for maximum flow. To study the impacts of said parameters, an experimental study of air flow through open cell metal foams is performed. Seven foam blocks were used in this partial factorial study, representing varying materials, pore size, and porosity. Wind tunnel tests are performed to measure the velocity of air flowing through the foam as a function of the free stream air velocity. Multinomial logit regression was performed to analyze the effects of the design parameters on velocity loss through the foam. Results indicate that effect of porosity on velocity loss is significant while that of pore size is insignificant. However, one test result did not fit this trend and further investigation revealed that this was due to varying ligament geometry in outlier metal foam. The cross section shape of the ligaments varied from a convex triangular shape to a triangle shape with concave surfaces, increasing the amount of drag in the airflow through the sample.

scholarly journals Numerical Assessment of an Innovative Design of an Evacuated Tube Solar Collector Incorporated with PCM Embedded Metal Foam/Plate Fins

2021 ◽  
Vol 13 (19) ◽  
pp. 10632
Author(s):  
Mohamed Houcine Dhaou ◽  
Sofiene Mellouli ◽  
Faisal Alresheedi ◽  
Yassine El-Ghoul
Keyword(s):  
Heat Transfer ◽  
Pore Size ◽  
Thermal Performance ◽  
Solar Collector ◽  
Metal Foam ◽  
Metal Foams ◽  
Heat Transfer Fluid ◽  
Evaluation Procedure ◽  
Evacuated Tube Solar Collector ◽  
Evacuated Tube

The objective of this manuscript is to study the possibility of improving the thermal performance of an Evacuated Tube Solar Collector (ETSC) with the integration of a Phase Change Material (PCM) incorporated into metallic foam and fitted with plate fins. A 2D mathematical model has been proposed. Two types of metal foams (copper and nickel) were inserted. In addition, the effect of metal foam pore size of on heat transfer was studied. The results were acquired through numerical simulations of four different cases; namely, Case 1: pure PCM, Case 2: with metal foam, Case 3: with fins and Case 4: with metal foam and fins. The evaluation procedure involved observing the total change in Heat Transfer Fluid (HTF) temperature and melted PCM fraction during a single day. The results proved that the thermal performance of ETSC is improved considerably by inserting metal foam and fins simultaneously. The time required for the whole process is improved by almost 9% compared to the case of pure PCM, and 2% compared to the case of inserting only plate fins. Results revealed that the pore size of the metal foams slightly affects the dynamic process of heat storage/release in the ETSC/PCM system.

The Fracture Properties of Sandwich Structures Based on a Metal Foam Core

2014 ◽  
Vol 936 ◽  
pp. 2054-2062
Author(s):  
Yiou Shen ◽  
Yan Li ◽  
Wesley Cantwell ◽  
Yu Yuan Zhao
Keyword(s):  
Metal Foam ◽  
Sandwich Structures ◽  
Compaction Pressure ◽  
Metal Foams ◽  
Compression Tests ◽  
Fracture Properties ◽  
Indentation Tests ◽  
Point Bend ◽  
Average Size ◽  
Two Parameters

The fracture properties of a series of metal foam sandwich structures based on glass fiber-reinforced polyamide 6,6 composite (GF/PA6,6) skins have been investigated. The open cell core materials were manufactured using the Lost Carbonate Sintering (LCS) process, a recently-developed technique for manufacturing metal foams. Initially, the effect of varying the compaction pressure used in producing the metal foams as well as the density of the samples were investigated through a series of compression tests. Here, it was shown that the compressive strength and the elastic modulus of the foams varied with density and compaction pressure, in spite of the fact that the average size of the cells in these foams were insensitive to either of these two parameters. The resistance of sandwich structures to localized loading was investigated through a series of indentation tests. Here, it was shown that the indentation response of sandwich structures could be characterized using a simple indentation law, the parameters of which did not exhibit any clear dependency on the density of the foam. Finally, three point bend tests on the sandwich structures have shown that their loading-bearing properties were sensitive to foam density.

Novel Lightweight Metal Foam Heat Exchangers

2001 ◽  
Author(s):  
David P. Haack ◽  
Kenneth R. Butcher ◽  
T. Kim ◽  
T. J. Lu
Keyword(s):  
Heat Exchange ◽  
Pore Size ◽  
Heat Exchangers ◽  
Metal Foam ◽  
Heat Removal ◽  
Random Orientation ◽  
Flow Rates ◽  
Small Pore ◽  
Complex Heat Exchange ◽  
Flow Through

Abstract An overview of open cell metal foam materials with application to advanced heat exchange devices is presented. The metal foam materials considered consist of interconnected cells in a random orientation. Metal foam materials, manufacture and fabrication into complex heat exchange components are described. Experiments with flat foam panels brazed to copper sheets shows increasing heat removal effectiveness with decreasing product pore size at equivalent coolant flow rates. However, the high-pressure drop associated with flow through small pore-size material makes the use of larger pore size material more attractive.

Thermal Dispersion in Metal Foams

2011 ◽  
Author(s):  
Teresa B. Hoberg ◽  
Kenshiro Muramatsu ◽  
Erica M. Cherry ◽  
John K. Eaton
Keyword(s):  
Heat Transfer ◽  
Molecular Diffusion ◽  
Metal Foam ◽  
Heated Surface ◽  
High Surface ◽  
Metal Foams ◽  
Thermal Engineering ◽  
Transfer Model ◽  
Thermal Dispersion ◽  
Transverse Mixing

Open-cell metal foams are of interest for a variety of thermal engineering applications because of their high surface-to-volume ratio and high convective heat transfer coefficients relative to conventional fins. The tortuous flow path through the foam promotes rapid transverse mixing, a fact that is important in heat exchanger applications. Transverse mixing acts to spread heat away from a heated surface, bringing cooler fluid to the foam elements that are in direct contact with the surface. Heat is also spread by conduction in the foam ligaments. The present work addresses fully-coupled thermal dispersion in a metal foam. Dispersion of the thermal wake of a line source was measured. A conjugate heat transfer model was developed which showed good agreement with the data. The validated model was used to examine the complementary effects of the mechanical dispersion, molecular diffusion in the gas, and conduction in the solid.

Experimental and numerical thermal analysis of open-cell metal foams developed through a topological optimization and 3D printing process

2018 ◽  
Vol 83 (1) ◽  
pp. 10904 ◽  
Author(s):  
Abdelatif Merabtine ◽  
Nicolas Gardan ◽  
Julien Gardan ◽  
Houssem Badreddine ◽  
Chuan Zhang ◽  
...  
Keyword(s):  
Thermal Analysis ◽  
3D Printing ◽  
Numerical Simulations ◽  
Lattice Model ◽  
Metal Foam ◽  
Complex Geometry ◽  
Metal Foams ◽  
Topological Optimization ◽  
Plaster Mold ◽  
Open Cell

This study focuses on the thermal analysis and comparing a lattice model and an optimized model of open-cell metal foams manufactured thanks to a metal casting process. The topological optimization defines the complex geometry through thermal criteria and a plaster mold reproduces it in 3D printing to be used in casting. The study of the thermal behavior conducted on the two open foam metal structures is performed based on several measurements, as well as numerical simulations. It is observed that the optimized metal foam presented less and non-homogenous local temperature than the lattice model with the gap of about 10 °C between both models. The pore size and porosity significantly affect the heat transfer through the metal foam. The comparison between numerical simulations and experimental results regarding the temperature fields shows a good agreement allowing the validation of the developed three-dimensional model based on the finite element method.

scholarly journals Shape-Controlled, Single-Crystal Gold Surface Nanostructures

2019 ◽  
Author(s):  
Sasan V. Grayli ◽  
Xin Zhang ◽  
Dmitry Star ◽  
Gary Leach
Keyword(s):  
Single Crystal ◽  
Electroless Deposition ◽  
Near Field ◽  
Critical Role ◽  
Deposition Process ◽  
Local Fields ◽  
Metal Nanostructures ◽  
Large Area ◽  
Device Applications ◽  
Shape Controlled

Size, shape and crystallinity play a critical role in the wavelength-dependent optical responses and plasmonic local near-field distributions of metallic nanostructures. While their enhanced local fields can drive new and useful chemical and physical processes, the ability to fabricate shape-controlled single-crystal metal nanostructures and position them precisely on substrates for device applications represents a significant barrier to harnessing their greater potential. Here, we describe a novel electroless deposition process in the presence of anionic additives that yields additive-specific, shape-controlled, single-crystal plasmonic Au nanostructures on Ag(100) and Au(100) substrates. Deposition of Au in the presence of SO<sub>4</sub><sup>2-</sup> ions results in the formation of smooth Au(111)-faceted square pyramids that show large surface enhanced Raman responses. The use of halide additives such as Cl<sup>-</sup> and Br<sup>- </sup>that interact strongly with (100) facets produces highly textured hillock-type structures characterized by edge and screw-type dislocations (Cl<sup>-</sup>), or flat platelet-like features characterized by large area Au(100) terraces with (110) step edges (Br<sup>-</sup>). Use of additive combinations provides structures that comprise characteristics derived from each additive including new square pyramidal structures with dominant Au(110) facets (SO<sub>4</sub><sup>2-</sup>and Br<sup>-</sup>). Finally we demonstrate that this bottom-up electroless deposition process, when combined with top-down lithographic patterning methods, can be used to position shape-controlled, single-crystal Au nanostructures with precise location and orientation on surfaces. We anticipate that this approach will be employed as a powerful new tool to tune the plasmonic characteristics of nanostructures and facilitate their broader integration into device applications.

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