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Dissertations / Theses on the topic 'Aluminum – Surfaces'

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Published: 4 June 2021
Last updated: 6 September 2023

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1

Whitten, James E. "Electron-stimulated desorption from aluminum surfaces /." The Ohio State University, 1991. http://rave.ohiolink.edu/etdc/view?acc_num=osu14876939231976.

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2

Lopez, Ken S. B. Massachusetts Institute of Technology. "Hierarchical superhydrophobic aluminum surfaces for condensation applications." Thesis, Massachusetts Institute of Technology, 2012. http://hdl.handle.net/1721.1/74448.

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Thesis (S.B.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.
Cataloged from PDF version of thesis.
Includes bibliographical references (p. 51).
Many existing industrial systems, including thermal desalination plants and air conditioning systems, involve the process of condensation and are heavily dependent on this process for achieving adequate levels of energy efficiency. In order to obtain these levels of efficiency, condensation heat transfer must be optimized through the application of dropwise condensation. One ongoing solution for improving the performance of dropwise condensation is the implementation of superhydrophobic structures and chemistries on condensing surfaces. Aluminum, being a heavily utilized material in many condensing systems and other industrial applications, is the subject of the present study. This thesis presents methods for synthesizing aluminum surfaces to produce microstructured morphologies through chemical etching with hydrogen chloride and oxidation with sodium hydroxide. After functionalization of these surfaces with a hydrophobic surface coating, the surfaces were tested for condensation using optical microscopy and a high quality environmental chamber. From experimentation, condensed droplets on these surfaces were unable to achieve the proper Wenzel to Cassie-Baxter transition and produce a jumping behavior which is a necessary criterion for superhydrophobic condensation. However, the HCl etched aluminum surface was able to achieve heat transfer rates greater than the smooth, filmwise aluminum surface by a factor of 2 and greater than the smooth, dropwise aluminum surface by a factor of 5/3. This implies that these structures were still capable of improving heat transfer rates despite their inability to surpass the energy barrier required for superhydrophobic condensation.
by Ken Lopez.
S.B.
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3

Kuo, Shun-meen. "Surface and subsurface deformation of aluminum and aluminum alloys in dry sliding wear /." The Ohio State University, 1987. http://rave.ohiolink.edu/etdc/view?acc_num=osu1487325740717942.

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4

Pokrajac, Lisa A. "Fundamental studies of polyurethane - aluminum adhesion, phenyl isocyanate interaction with prepared aluminum oxide surfaces." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape10/PQDD_0006/MQ40733.pdf.

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5

Thieme, Michael, Christa Blank, de Oliveira Aline Pereira, Hartmut Worch, Ralf Frenzel, Susanne Höhne, Frank Simon, Lewis Hilton G. Pryce, and Aleksandr J. White. "Superhydrophobic Aluminum Surfaces: Preparation Routes, Properties and Artificial Weathering Impact." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-107085.

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Among the materials that can be treated in order to impart superhydrophobic properties are many originally hydrophilic metals. For this, they must undergo a sequential treatment, including roughening and hydrophobic coating. This contribution presents various preparation routes along with various characterization methods, such as dynamic contact angle (DCA) measurements, scanning electron microscopy (SEM) and spectroscopic techniques (FT–IRRAS, XPS, EIS). Micro-rough surfaces of pure and alloyed aluminum were generated most easily by using a modifie Sulfuric Acid Anodization under Intensifie conditions (SAAi). This produces a micro-mountain-like oxide morphology with peak-to-valley heights of 2 μm and sub-μm roughness components. Additionally, micro-embossed and micro-blasted surfaces were investigated. These micro-roughened initial states were chemically modifie with a solution of a hydrophobic compound, such as the reactive f uoroalkylsilane PFATES, the reactive alkyl group containing polymer POMA, or the polymer Teflo ® AF. Alternatively, the chemical modificatio was made by a Hot Filament Chemical Vapor Deposition (HFCVD) of a PTFE layer. The latter can form a considerably higher thickness than the wet-deposited coatings, without detrimental leveling effects being observed in comparison with the original micro-rough surface. The inherent and controllable morphology of the PTFE layers represents an important feature. The impacts of a standardized artificia weathering (WTH) on the wetting behavior and the surface-chemical properties were studied and discussed in terms of possible damage mechanisms. A very high stability of the superhydrophobicity was observed for the f uorinated wet-deposited PFATES and Teflo ® AF coatings as well as for some of the PTFE layer variants, all on SAAi-pretreated substrates. Very good results were also obtained for specimens produced by appropriate mechanical roughening and PTFE coating.
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6

Thieme, Michael, Christa Blank, de Oliveira Aline Pereira, Hartmut Worch, Ralf Frenzel, Susanne Höhne, Frank Simon, Lewis Hilton G. Pryce, and Aleksandr J. White. "Superhydrophobic Aluminum Surfaces: Preparation Routes, Properties and Artificial Weathering Impact." Technische Universität Dresden, 2009. https://tud.qucosa.de/id/qucosa%3A26716.

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Among the materials that can be treated in order to impart superhydrophobic properties are many originally hydrophilic metals. For this, they must undergo a sequential treatment, including roughening and hydrophobic coating. This contribution presents various preparation routes along with various characterization methods, such as dynamic contact angle (DCA) measurements, scanning electron microscopy (SEM) and spectroscopic techniques (FT–IRRAS, XPS, EIS). Micro-rough surfaces of pure and alloyed aluminum were generated most easily by using a modifie Sulfuric Acid Anodization under Intensifie conditions (SAAi). This produces a micro-mountain-like oxide morphology with peak-to-valley heights of 2 μm and sub-μm roughness components. Additionally, micro-embossed and micro-blasted surfaces were investigated. These micro-roughened initial states were chemically modifie with a solution of a hydrophobic compound, such as the reactive f uoroalkylsilane PFATES, the reactive alkyl group containing polymer POMA, or the polymer Teflo ® AF. Alternatively, the chemical modificatio was made by a Hot Filament Chemical Vapor Deposition (HFCVD) of a PTFE layer. The latter can form a considerably higher thickness than the wet-deposited coatings, without detrimental leveling effects being observed in comparison with the original micro-rough surface. The inherent and controllable morphology of the PTFE layers represents an important feature. The impacts of a standardized artificia weathering (WTH) on the wetting behavior and the surface-chemical properties were studied and discussed in terms of possible damage mechanisms. A very high stability of the superhydrophobicity was observed for the f uorinated wet-deposited PFATES and Teflo ® AF coatings as well as for some of the PTFE layer variants, all on SAAi-pretreated substrates. Very good results were also obtained for specimens produced by appropriate mechanical roughening and PTFE coating.
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7

Saint-Cast, Pierre [Verfasser]. "Passivation of Si Surfaces by PECVD Aluminum Oxide / Pierre Saint-Cast." Konstanz : Bibliothek der Universität Konstanz, 2012. http://d-nb.info/1048524833/34.

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8

Alheshibri, Muidh Hamed. "USING GRADIENTS TO MANIPULATE WATER DROPLET BEHAVIOR ON COPPER AND ALUMINUM SURFACES." Miami University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=miami1386599950.

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9

Tait, Steven L. "Desorption kinetics of small n-alkanes from MgO(100), Pt(111), and C(0001)/Pt(111) and studies of Pd nanoparticles : growth and sintering on Al₂O₃(0001) and methane dissociation on MgO(100) /." Thesis, Connect to this title online; UW restricted, 2005. http://hdl.handle.net/1773/9630.

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10

Niu, Chengyu. "Metal-Aluminum Oxide Interactions: Effects of Surface Hydroxylation and High Electric Field." Thesis, University of North Texas, 2001. https://digital.library.unt.edu/ark:/67531/metadc3039/.

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Metal and oxide interactions are of broad scientific and technological interest in areas such as heterogeneous catalysis, microelectronics, composite materials, and corrosion. In the real world, such interactions are often complicated by the presence of interfacial impurities and/or high electric fields that may change the thermodynamic and kinetic behaviors of the metal/oxide interfaces. This research includes: (1) the surface hydroxylation effects on the aluminum oxide interactions with copper adlayers, and (2) effects of high electric fields on the interface of thin aluminum oxide films and Ni3Al substrate. X-ray photoelectron spectroscopy (XPS) studies and first principles calculations have been carried out to compare copper adsorption on heavily hydroxylated a- Al2O3(0001) with dehydroxylated surfaces produced by Argon ion sputtering followed by annealing in oxygen. For a heavily hydroxylated surface with OH coverage of 0.47 monolayer (ML), sputter deposition of copper at 300 K results in a maximum Cu(I) coverage of ~0.35 ML, in agreement with theoretical predictions. Maximum Cu(I) coverage at 300 K decreases with decreasing surface hydroxylation. Exposure of a partially dehydroxylated a-Al2O3(0001) surface to either air or 2 Torr water vapor results in recovery of surface hydroxylation, which in turn increases the maximum Cu(I) coverage. The ability of surface hydroxyl groups to enhance copper binding suggests a reason for contradictory experimental results reported in the literature for copper wetting of aluminum oxide. Scanning tunneling microscopy (STM) was used to study the high electric field effects on thermally grown ultrathin Al2O3 and the interface of Al2O3 and Ni3Al substrate. Under STM induced high electric fields, dielectric breakdown of thin Al2O3 occurs at 12.3 } 1.0 MV/cm. At lower electric fields, small voids that are 2-8 A deep are initiated at the oxide/metal interface and grow wider and deeper into the metal substrate, which eventually leads to either physical collapse or dielectric breakdown of the oxide film on top.
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11

Chen, Liang-Yu. "Secondary ions sputtered by low energy ion bombardment of copper and aluminum surfaces." Case Western Reserve University School of Graduate Studies / OhioLINK, 1995. http://rave.ohiolink.edu/etdc/view?acc_num=case1058535998.

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12

Sutcliffe, Ronald David. "Aluminum and Copper Chemical Vapor Deposition on Fluoropolymer Dielectrics and Subsequent Interfacial Interactions." Thesis, University of North Texas, 1997. https://digital.library.unt.edu/ark:/67531/metadc279304/.

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13

Claycomb, Gregory D. "Surface analysis applied to the development of surfaces for practical application with a focus on aluminum and its alloys /." Search for this dissertation online, 2006. http://wwwlib.umi.com/cr/ksu/main.

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14

Accardo, Mario G. "Effects of high pressure water jet on aluminum surfaces prior to thermal spray coating." Master's thesis, This resource online, 1995. http://scholar.lib.vt.edu/theses/available/etd-10222009-124845/.

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15

Addepalli, Swarnagowri. "High-Temperature Corrosion of Aluminum Alloys: Oxide-Alloy Interactions and Sulfur Interface Chemistry." Thesis, University of North Texas, 2000. https://digital.library.unt.edu/ark:/67531/metadc2739/.

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The spallation of aluminum, chromium, and iron oxide scales is a chronic problem that critically impacts technological applications like aerospace, power plant operation, catalysis, petrochemical industry, and the fabrication of composite materials. The presence of interfacial impurities, mainly sulfur, has been reported to accelerate spallation, thereby promoting the high-temperature corrosion of metals and alloys. The precise mechanism for sulfur-induced destruction of oxides, however, is ambiguous. The objective of the present research is to elucidate the microscopic mechanism for the high-temperature corrosion of aluminum alloys in the presence of sulfur. Auger electron spectroscopy (AES), low energy electron diffraction (LEED), and scanning tunneling microscopy (STM) studies were conducted under ultrahigh vacuum (UHV) conditions on oxidized sulfur-free and sulfur-modified Al/Fe and Ni3Al(111). Evaporative deposition of aluminum onto a sulfur-covered iron surface results in the insertion of aluminum between the sulfur adlayer and the substrate, producing an Fe-Al-S interface. Aluminum oxidation at 300 K is retarded in the presence of sulfur. Oxide destabilization, and the formation of metallic aluminum are observed at temperatures > 600 K when sulfur is located at the Al2O3-Fe interface, while the sulfur-free interface is stable up to 900 K. In contrast, the thermal stability (up to at least 1100 K) of the Al2O3 formed on an Ni3Al(111) surface is unaffected by sulfur. Sulfur remains at the oxide-Ni3Al(111) interface after oxidation at 300 K. During annealing, aluminum segregation to the g ¢ -Al2O3-Ni3Al(111) interface occurs, coincident with the removal of sulfur from the interfacial region. A comparison of the results observed for the Al2O3/Fe and Al2O3/Ni3Al systems indicates that the high-temperature stability of Al2O3 films on aluminum alloys is connected with the concentration of aluminum in the alloy.
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16

Belenguer, Rizo Marc. "Funcionalització de superfícies d'alumini anoditzat." Doctoral thesis, Universitat de Barcelona, 2016. http://hdl.handle.net/10803/396301.

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Utilitzant una tecnologia implementada prèviament en el grup, en aquesta Tesi s'ha optimitzat el procés de formació de plantilles d'Alumini / Alúmina mitjançant anoditzat d'aliatges AA 1050 i 1080. L'estructura i geometria de les plantilles s'ha optimitzat mitjançant tècniques de reducció de la capa barrera (procés BLT) i d'obertura de porus (procés OBL i atac amb àcid fosfòric). Amb aquestes plantilles s'han obtingut electroquímicament nanoestructures 1D de Ni, Au i Co. En tots els casos s'ha comprovat que les úniques tècniques que permeten obtenir nanodipòsits de qualitat són les polsants, amb polsos complexos que combinen polsos de reducció, d'oxidació i a circuit obert. Amb tots els metalls s'ha estudiat el procés de creixement i s'ha constatat que hi ha importants diferències entre el creixement del níquel i el dels altres dos metalls: mentre el creixement dels nanofils de Ni es produeix uniformement en tots els porus de la plantilla, els de Au i Co es produeixen en feixos distribuïts aleatòriament per tota la superfície. En un estudi paral•lel de les primeres etapes de l'anoditzat, s'ha caracteritzat l'estructura i composició de les protuberàncies que apareixen en l'anomenat procés de cremat (burning) de l’alumini; s'ha comprovat que en tots els casos en què apareixen aquestes protuberàncies l'EDX detecta Fe en el vèrtex. Es tracta, doncs, de les restes d'una partícula inter-metàl•lica AI Fe Si , dissolta en el pretractament de I 'alumini .
Using a technology previously implemented in the group, in this PhD thesis the process of obtaining aluminium/alumina templates has been optimized by anodizing AA1050 and 1080 aluminium alloys. The structure and geometry of the template has been optimized using techniques such as barrier layer reduction (BLT process) and opening of pores (OBL process and attack with phosphoric acid). With these templates 1D nanostructures of Ni, Au and Co have been obtained electrochemically. Pulse techniques have demonstrated to be the most suitable to obtain the nanowires. The growth process has been studied for all metals and it has been verified that, while the growth of Ni nanowires occurs uniformly in all the pores of the template, those of Au and Co do occur randomly distributed across the surface. In a parallel study of the early stages of anodization, the structure and composition of the bumps that appear in the process called burning of aluminium have been characterized. In all cases Fe has been detected at the apex of the bumps. It is, therefore, the remains of an intermetallic particle of A1FeSi dissolved in the pretreatment of aluminium.
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17

Mertens, Jeremy. "Atmospheric plasma treatment of aluminum alloy surfaces: Oxide growth and oxygen rich organic coating deposition." Doctoral thesis, Universite Libre de Bruxelles, 2019. https://dipot.ulb.ac.be/dspace/bitstream/2013/287803/3/these.pdf.

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L’objectif de cette thèse consiste en une étude fondamentale de différentes approches pour la modification de surfaces d’alliages d’aluminium. Elle s’inscrit dans le cadre du projet FLYCOAT, subventionné par la région Wallonne. Ce dernier avait pour objectif le développement d’alternatives au couplage classique d’un procédé d’anodisation utilisant des bains de Cr (VI) aux résines époxy pour la protection des alliages d’aluminium contre la corrosion. Dans un premier temps, la synthèse par plasma atmosphérique dans un réacteur de type décharge à barrière diélectrique (DBD) de films riches en groupements carboxyliques à partir de 8 précurseurs organiques est étudiée. Une attention particulière est portée à la compréhension fondamentale des mécanismes de polymérisation de ces précurseurs. L’influence significative de minimes variations de la structure chimique du précurseur est étudiée. Concrètement, nous démontrons l’impact de la présence et de la position de doubles liaisons ou encore le ratio C/O dans le monomère injecté sur le mécanisme de synthèse des couches déposées. Pour ce faire, une méthodologie combinant des analyses de la phase plasma et des films déposés est proposée. Les propriétés électriques de la DBD d’argon sont évaluées par oscilloscope avant et durant l’injection des différents précurseurs. La quantité d’énergie transférée de la décharge vers le précurseur est évaluée par spectroscopie d’émission optique et corrélée à sa structure. Une fragmentation réduite est mise en évidence par spectrométrie de masse pour les monomères contenant une double liaison. Ces analyses de la phase plasma sont alors corrélées avec les propriétés physiques et chimiques des films synthétisés. Les compositions chimiques de surface et de la matrice des couches minces sont étudiées par spectroscopie à photoélectrons X (XPS) et infrarouge. Le rôle essentiel de la présence et de la position de la double liaison dans la molécule injectée est démontré. Les vitesses de dépôt et la rugosité des films déposés par plasma atmosphérique avec l’injection des 8 précurseurs sont évaluées par profilométrie à stylet. Dans la seconde partie, le couplage de deux méthodes de plasma atmosphérique est proposé pour la synthèse de couches d’alumine aux propriétés adaptables. Le premier traitement consiste en un nombre varié de passages d’une torche plasma opérant dans un régime d’arc. L’effet du nombre de passages sur les propriétés physiques et chimiques du substrat est étudié par XPS, angle de contact, microscopie électronique à balayage et mesures de diffraction à rayons X. Une corrélation est suggérée entre le nombre de passages de la torche et les propriétés électrochimiques du substrat. L’influence de ce premier traitement sur les propriétés de la couche d’oxyde d’aluminium synthétisée par oxydation par plasma électrolytique est mise en évidence. Dans un troisième temps, le plasma pouvant être considéré comme un réservoir d’énergie, une étude de faisabilité est réalisée afin d’évaluer sa potentielle utilisation pour la réticulation d’une résine de type benzoxazine. L’efficacité du traitement par DBD atmosphérique d’argon ou hélium est comparée et discutée.
Doctorat en Sciences
info:eu-repo/semantics/nonPublished
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18

Cornette, Pauline. "Approche expérimentale et théorique de l’inhibition de corrosion de surfaces métalliques." Thesis, Paris Sciences et Lettres (ComUE), 2018. http://www.theses.fr/2018PSLEC004.

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La corrosion des surfaces d’aluminium et d’alliages aluminium/cuivre, et notamment la corrosion localisée, est un problème majeur dans l’industrie, et l’utilisation d’inhibiteur de corrosion est bien souvent indispensable. Les chromates remplissent parfaitement leurs rôles d’inhibition mais seront d’ici peu interdits en raison de leurs toxicités pour l’homme et l’environnement. La compréhension des mécanismes de corrosion et d’inhibition de la corrosion est alors un réel défi de la recherche aujourd’hui. Ce travail de thèse s’organise autour de trois axes de recherche : la compréhension des mécanismes d’initiation de la corrosion de l’aluminium, la relation entre la composition chimique et la résistance à la corrosion des alliages aluminium/cuivre, et enfin l’étude des acides carboxyliques linéaires en tant qu’inhibiteurs verts de corrosion. Ce projet s’appuie sur deux approches complémentaires : une approche théorique, basée sur des calculs DFT, et une approche expérimentale combinant des techniques d'analyse des surfaces ainsi que des techniques électrochimiques. Dans un premier temps, la réactivité vis-à-vis de O2 de modèles de couches minces d’alumine sur aluminium métallique, a été étudiée par calculs ab initio en présence de lacunes d’oxygène dans l’oxyde, ou de cuivre dans le métal, ainsi qu’en présence d’une monocouche d’acides carboxyliques sur la surface. Des techniques d'analyse de surface (XPS, ToF-SIMS, AFM et MEB) ont ensuite été utilisées pour analyser la composition chimique et la morphologie de surfaces d’aluminium pur et d’alliages modèles Al/Cu avant et après adsorption d’une monocouche d’acides carboxyliques. L’influence de la présence de cette couche en surface sur la corrosion en milieu chloruré est finalement étudiée par mesures électrochimiques
Corrosion of aluminum and aluminum/copper alloy surfaces, including localized corrosion, is a major problem in the industry, and the use of a corrosion inhibitor is often essential. Chromates perfectly fulfill their role of inhibition but will soon be prohibited because of their toxicities for humans and environment. Understanding the mechanisms of corrosion and corrosion inhibition is therefore a real challenge for research today. This thesis work is organized around three lines of research: the understanding of the aluminum corrosion initiation mechanisms, the relationship between the chemical composition of the alloy and the corrosion resistance of aluminum/copper alloys, and finally the study of linear carboxylic acids as green corrosion inhibitors. This project relies on two complementary approaches: a theoretical approach, based on DFT calculations, and an experimental approach combining surface analysis techniques as well as electrochemical techniques. First, the reactivity with respect to O2 of alumina thin film models on metallic aluminum, was studied by ab initio calculations in the presence of oxygen vacancies in the oxide, or copper in the metal, as well as in the presence of a carboxylic acids monolayer on the surface. Surface analysis techniques (XPS, ToF-SIMS, AFM and SEM) were then used to analyze the chemical composition and morphology of pure aluminum surfaces and Al/Cu model alloys before and after adsorption. a carboxylic acids monolayer. The influence of the presence of this surface layer on the corrosion in chloride medium is finally studied by electrochemical measurements
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19

Holmes, Brenda L. "Effect of a derivatized oxide layer and environment on the bond durability of aluminum/polyimide and titanium/polyimide bonds." Thesis, Virginia Tech, 1994. http://hdl.handle.net/10919/41597.

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A surface pretreatment for aluminum and titanium involving the reaction of phosphonic acid (RPO(OH)2), R=butyl or vinyl for aluminum and R=vinyl for titanium, has been investigated. The durability of phosphonic acid-pretreated samples was compared with that for P2-etched (ferric sulfate-sulfuric acid) adherends. Samples were bonded with LaRC-IA adhesive in a wedge test geometry. Environmental testing consisted of static and cyclical exposure for 240 hours in three atmospheres: 1) 170°C, 2 torr; 2) -20°C; 3) 60°C, 70% relative humidity. Crack propagation arrested within 48 hours. The order of durability in static environmental tests for aluminum was vinyl phosphonic acid > P2 > butyl phosphonic acid. The durability performance was reversed for cyclic testing. The durability of specimens using P2-etched titanium was superior to that for vinyl phosphonic acid-treated titanium in all environmental tests.
Master of Science

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20

Do, Than. "Electron spectroscopic studies on the growth mechanism of oxide on aluminum surfaces exposed to water vapour." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape4/PQDD_0018/NQ58125.pdf.

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21

Sharpe, Matthew. "On the Interaction of Tritium with the Surfaces of Aluminum, Copper, Stainless Steel (type 316), and Gold." Thesis, University of Rochester, 2016. http://pqdtopen.proquest.com/#viewpdf?dispub=10157770.

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The interaction of tritium with aluminum, copper, stainless steel, and gold plated substrates was studied using a low-pressure, argon plasma, as well as thermal desorption spectroscopy. These experimental methods allowed the influence of modifying metal surfaces on the absorption and adsorption of tritium to be measured. Stainless steel surfaces were modified by mechanical polishing, electropolishing, selective oxidation pre-treatments, and gold plating. The only surface modification performed on aluminum and copper samples was gold plating.

Use of the low-pressure plasma constitutes a novel approach to studying tritium migration and to measuring the quantity of adsorbed tritium. The migration of tritium was inferred from experiments, where a metal sample was exposed to a pulsed plasma. In such a method, tritium migration to the surface in between each pulse influences the quantity of tritium removed during subsequent plasma pulses. The results of these measurements indicated that the mechanism for tritium migration to the surface was limited by diffusion out of the underlying metal lattice. The measured rate of tritium migration to the surface does not appear to depend strongly on the metal type or surface modification.

Thermal desorption experiments were used to measure the influence of modifying metal surfaces on the total absorption of tritium. Thermal desorption involves heating samples to high temperatures for protracted periods of time, in order to remove all tritium contained within the metal lattice. These measurements indicated that modifying a metal surface significantly influences the total absorption of tritium during room temperature (25°C) exposures.

Finally, a quantitative tritium migration model (QTRIMM) was developed in this work to describe the transport of the isotope through metal lattices. Additionally, QTRIMM includes a condition that relates the tritium concentrations adsorbed to the surface to the concentrations within the metal lattice. This model represents a major step forward in describing the migration of tritium through metal substrates, as many previous transport models have not included a condition for tritium adsorption. As demonstrated in this study, QTRIMM describes the measured data reasonably well.

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22

Ramsey, Jeremy D. "The corrosion inhibition mechanism of Chromium(VI) : probing the interaction of Chromium(VI) with Aluminum Alloy surfaces /." The Ohio State University, 2001. http://rave.ohiolink.edu/etdc/view?acc_num=osu1488205318508842.

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23

Dunn, Darrell Scott. "Characterization and evaluation of anodized commercially pure titanium and titanium-aluminum-vanadium alloy surfaces for systemic antibiotic release." Thesis, The University of Arizona, 1990. http://hdl.handle.net/10150/144641.

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Postoperative infections are one of the most feared complications following orthopedic implant procedures. Bacterial infections occur in approximately 1-2% of the patients who undergo orthopedic implant surgery. Treatment of these infections is typically done by administering antibiotics either locally or systemically. Systemic release of antibiotics from bone cement has been reasonably successful. However, it would also be desirable to develop a method of antibiotic release from porous coated implants designed for osseointegration. The principal objective of this research was to explore the feasibility of using anodizing (electrochemical oxidation) as a surface modification technique to facilitate the attachment of antibiotics to commercially pure titanium (CP Ti) and Ti-6Al-4V orthopedic implant materials. In particular the effect of anodizing conditions on the characteristics of the oxide coating such as thickness, composition and porosity has been investigated. Using microbiological methods, the efficacy of in-vitro attachment of antibiotics to anodized surfaces was determined.
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24

FONTANOT, TOMMASO. "Experimental characterization of surfaces and metal-polymer heterostacks of optical systems for the automotive sector." Doctoral thesis, Università degli Studi di Trieste, 2021. http://hdl.handle.net/11368/2981746.

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The main target of the project consisted in applying the thorough experimental methodology typical of surface physics and materials science to the characterization of materials to be exploited in the automotive lighting sector. Several aspects were considered, thus covering a variety of surface, materials, optical, and physical properties of polymer and metal-polymer reflectors and lenses. The development of a concept machine with the aim of automatically scanning defective outer lenses based on a computer vision system has also been validated. The algorithms of the inspection system, developed in order to avoid the human-eye control, have been fine-tuned to increase the performance and the reliability of the prototype machine. Following the experience on the lenses’ inspection, the attention has been focused on reflecting elements. A reflector is one of the many components of rear automotive lamps. Its purpose is both to reflect light generated by a source and to provide a selected aesthetic aspect. It is composed by metallic and protective thin films deposited over plastic substrates: in particular, the structural (thickness of the metal layer, surface roughness, composition…) and optical (specular and total reflectance, spectral dependency of the scattered beam …) properties have been accurately studied. Flat plastic substrates (made of polycarbonate -PC- and acrylonitrile butadiene styrene -ABS-) have been metallized in vacuo (10-4 mbar) through Physical Vapor Deposition (PVD) of aluminum with the subsequent deposition of a protector made of hexamethyldisiloxane (HMDSO) to prevent both chemical and mechanical damaging. The structural properties of metal-polymer heterostacks have been characterized by means of Atomic Force Microscopy (AFM), determining the surface roughness and the thickness of the diverse layers. Different metallization treatments were compared in a thorough characterization of the optical properties by measuring the spectral Bidirectional Reflectance Distribution Function (BRDF). The optical data, corroborated with profilometry measurements, evidenced an important contribution from the surface deformations induced by the mold production process. The most proper techniques to investigate defects forming at the metallized surfaces and interfaces of reflectors have been identified. By means of a combined approach exploiting Scanning Electron Microscopy (SEM) and synchrotron radiation based X-ray computed tomography (SR-CT) interesting results were obtained, yielding insight into the nature of the defects both at the surface and at the metal-polymer buried interfaces. Finally, an innovative and unique prototype machine has been designed and commissioned. The machine has a double aim: on one side, it automatically recognizes the defects arising on the reflectors’ surfaces by visual scanning, while on the other side it checks the reflectance of the metallized layer exploiting optical processes. In fact, by means of specifically designed algorithms, a standard camera is able to determine if the aluminum thin film has the correct reflectance properties, i.e. if the reflector can be considered compliant or not. Furthermore, exploiting Support Vector Machines (SVM) supervised learning models the system, after a deep and precise training, can recognize autonomously the defects arising on the reflectors and classify them. During this three-years-long project, detailed information regarding the nature and origin of materials defects has been obtained. Moreover, the thorough studies involving the structural and optical properties of metal-polymer heterostacks led to a more precise and realistic representation of the reflectors’ surfaces in simulation environments. Finally, the two prototype machines allow for a faster, cheaper, more objective and reliable inspection of the components, providing real time information essential to monitor the production chain and detect potential problems.
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Garza, Michelle. "Reactivity of Oxide Surfaces and Metal-Oxide Interfaces: Effects of Water Vapor Pressure on Ultrathin Aluminum Oxide Films, and Studies of Platinum Growth Modes on Ultrathin Oxide Films and Their Effects on Adhesion." Thesis, University of North Texas, 2004. https://digital.library.unt.edu/ark:/67531/metadc4517/.

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The reactivity of oxide surfaces and metal-oxide interfaces play an important role in many technological applications such as corrosion, heterogeneous catalysis, and microelectronics. The focus of this research was (1) understanding the effects of water vapor exposure of ultrathin aluminum oxide films under non-ultrahigh vacuum conditions (>10-9 Torr) and (2) characterization of Pt growth modes on ultrathin Ta silicate and silicon dioxide films and the effects of growth modes on adhesion of a Cu overlayer. These studies were conducted with X-ray photoelectron spectroscopy (XPS). Ni3Al(110) was oxidized (10-6 Torr O2, 800K) followed by annealing (1100K). The data indicate that the annealed oxide film is composed of NiO, Al2O3 and an intermediate phase denoted here as "AlOx". Upon exposure of the oxide film at ambient temperature to increasing water vapor pressure (10-6 - 5 Torr), a shift in both the O(1s) and Al(2p)oxide peak maxima to lower binding energies is observed. In contrast, exposure of Al2O3/Al(polycrystalline) to water vapor under the same conditions results in a high binding energy shoulder in the O(1s) spectra which indicates hydroxylation. Spectral decomposition provides further insight into the difference in reactivity between the two oxide films. The corresponding trends of the O(1s)/Ni0(2p3/2) and Al(2p)/Ni0(2p3/2) spectral intensity ratios suggest conformal changes of the oxide film on Ni3Al(110). The growth behavior of sputter deposited Pt at ~300K on Ta silicate and SiO2 ultrathin films formed on Si(100) was investigated. The XPS data show that Pt deposition results in uniform growth or "wetting" on Ta silicate and 2-D cluster growth on SiO2. Electroless Cu deposition on ~11 monolayers (ML) Pt/Ta silicate film results in an adherent Cu film which passed the Scotch tape test. In contrast, electroless Cu deposition on ~11ML Pt/SiO2 results in a non-adherent Cu film due to weak Pt/SiO2 interaction.
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Rodriguez, Leal Barbara Maria. "Lubricants for Hot Stamping of Aluminum: Evaluation of Tribological Behavior and Cleanability." Thesis, Luleå tekniska universitet, Institutionen för teknikvetenskap och matematik, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:ltu:diva-86766.

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Working at elevated temperature has its challenges due to the high level of complexity whenthe tribosystems operate under harsh conditions, commonly resulting in an increase on thefriction and thermal softening that goes into severe adhesion, severe abrasion and materialtransfer. Despite considerable research, there is a lack of research on tribology applied to hightemperature processes.  The aim of this project is to understand the tribological behavior of tool steel sliding againstaluminum under lubrication conditions working at high temperature. Salt-based, graphite-based, and polymer-based lubricants were evaluated as they are commonly used for aluminum forming. The cleanability of the lubricants after being subjected to elevated temperatures is also studied. High temperature tribological tests were carried out in a reciprocating sliding flat-on-flat configuration for 15 seconds. Optical microscope, SEM and EDS were performed to analyze the specimens after the tribological tests. Then a cleanability study was done to evaluate the cleanability of the lubricants and the effect of temperature on the cleanability of the lubricant. The concentration of the lubricants played an important role in the lubricant’s friction stability and dispersion, particularly for the polymer-based and graphite-based lubricants. Under the tested conditions the salt-based lubricant was ineffective as it showed high and unstable friction. The 10 wt.% polymer-based lubricant concentration presented severe adhesion and material transfer from the aluminum onto the tool steel.  The effect of temperature on the cleanability of the lubricants was correlated to the temperature in which the lubricants start to degrade. Nevertheless, the best cleanability was achieved when using ethanol as a cleaning agent in combination with high pressure spraying, and wirebrush techniques. Mild and high alkaline agents had poor cleanability abilities resulting insurface damage and corrosion on the tool steel.
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Sripathi, Prajwal Swamy Payton Lewis Nathaniel. "Investigation into the effects of tool geometry and metal working fluids on tool forces and tool surfaces during orthogonal tube turning of aluminum 6061 alloy." Auburn, Ala., 2009. http://hdl.handle.net/10415/1963.

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28

Hartman, Jeffrey David. "Charaterization of the Growth of Aluminum Nitride and Gallium Nitride Thin Films on Hydrogen Etched and/or cleaned 6H-SiC(0001) Surfaces." NCSU, 2000. http://www.lib.ncsu.edu/theses/available/etd-20001013-161053.

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The surface morphology and atomic structure of nitrogen doped, n-type 6H-SiC(0001)Si wafers before and after various surface preparation techniques were investigated. As-received wafers were exposed to in-situ cleaning with or without excess silicon to obtain either a (rt3 x rt3)R30° or a (3 x 3) reconstructed surface. The resulting surfaces were characterized using reflection high-energy electron diffraction, photo-electron emission microscopy, and atomic force microscopy. An atomically clean, reconstructed surface was obtained via thermal annealing at 950ºC. Cleaning with excess silicon resulted in the formation of silicon islands on the surface. The surface morphology of hydrogen etched wafers depended upon their doping concentrations. Wafers with doping concentrations of greater than or equal 2.5 x 10E18 and less than 7 x 10E17 (ND-NA)/cm3 were investigated with the former exhibiting more surface features. The microstructure of all the samples showed regions with full and half unit cell high steps. An atomically clean, ordered, stepped surface was achieved via annealing at 1030 degrees Celcius. Chemical vapor cleaning resulted in the formation of silicon islands. The initial growth of AlN and GaN thin films on the cleaned, hydrogen etched 6H-SiC(0001) substrates were investigated using PEEM and AFM. The AlN films nucleated immediately and coalesced, except in the areas of the substrate surface which contained half unit cell height steps where pits were observed. The GaN films grown at 800ºC for 2.5 minutes exhibited nucleation and three-dimensional growth along the steps. The GaN films deposited at 700° C for 2 minutes grew three-dimensionally with coalescence of the film dependent upon the step structure. Almost complete coalescence occurred in regions with unit cell high steps and incomplete coalesce occurred in regions with half unit cell height steps. Films of AlN grown for 30 minutes via GSMBE on hydrogen etched surfaces exhibited two-dimensional growth and had an RMS roughness value of 4 Å. Films grown at 1000 ° C exhibited an SK growth mode and had rocking curve FWHM of 150-200 arcsecs. MOCVD grown films on hydrogen etched wafers had an RMS roughness value of 4 Å and a XRD rocking curve FWHM of approximately 260 acrsecs.

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Milles, Stephan [Verfasser], Andrés [Gutachter] Lasagni, Andrés [Akademischer Betreuer] Lasagni, Thomas [Gutachter] Arnold, and Wolfgang [Gutachter] Lippmann. "Fabrication of multifunctional aluminum surfaces using laser-based texturing methods / Stephan Milles ; Gutachter: Andrés Lasagni, Thomas Arnold, Wolfgang Lippmann ; Betreuer: Andrés Lasagni." Dresden : Technische Universität Dresden, 2021. http://d-nb.info/1239729251/34.

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30

Henkelman, Graeme. "Methods for calculating rates of transitions with application to catalysis and crystal growth /." Thesis, Connect to this title online; UW restricted, 2001. http://hdl.handle.net/1773/8557.

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31

Masiagutova, Elina. "Étude de la génération des topographies de surfaces latérales issues du procédé LPBF pour un alliage d’aluminium AlSi10Mg." Thesis, Lyon, 2022. http://www.theses.fr/2022LYSEE002.

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Dans le cadre de ce travail, la génération des surfaces produites par le procédé de fusion laser sur lit de poudre LPBF a été étudiée. Le LPBF est un procédé de fabrication additive qui peut conduire à de nouvelles opportunités (fabrication de structures complexes avec canaux internes, structures lattices). Ce procédé attire donc une attention considérable en particulier dans l'industrie aéronautique. Une étude de l’influence des paramètres primaires du procédé LPBF sur la génération des surfaces a été réalisée. Au cours de cette étude, la relation entre la rugosité des surfaces supérieures et latérales et la densité du matériau a été établie. Cela a permis de déterminer la première fenêtre de paramètres optimaux.Une analyse de la dispersion de la rugosité et la reproductibilité du procédé ont ensuite été réalisées. Cette analyse a révélé une importante dispersion de la rugosité, notamment d'une face à l'autre. En conséquence, des recommandations sur les mesures de surface ont été proposées.L'effet de différents paramètres secondaires est également étudié afin de mieux comprendre la génération de la surface latérale et de l'optimiser. Cette étude a montré que les compensations et les réglages de contour sont des paramètres clés qui peuvent contribuent à la réduction de la rugosité des surfaces latérales. Sur la base des résultats de ces études, la rugosité a pu être diminuée d’un Sa de 40 µm à un Sa de 10 μm.Enfin, cette thèse présente une nouvelle approche de modélisation de génération des topographies des surfaces latérales. L’approche est basée sur la géométrie du cordon (rayons de courbure). Elle permet de prendre en compte la position des cordons et des couches et prédit la rugosité pour différentes stratégies de lasage et paramètres de compensation
In the current study, surface generation during additive manufacturing (AM), especially the laser powder bed fusion (LPBF) process was studied. LPBF is a progressive process that can lead to new opportunities, such as applications that require complex structures (internal channels or lightweight lattice structures). It has therefore attracted considerable attention, which has led to research and development in many industries, particularly in the aerospace industry.A surface generation study to optimize surface roughness and material density by examining the influence of the primary LPBF process parameters was therefore performed. During this study, the relationship between the roughness of the top and side surfaces and the density of the material was established. This made it possible to determine the first window of optimal parameters.An analysis of the roughness dispersion and process reproducibility were then carried out. This analysis revealed a significant roughness dispersion, especially from one side to the other. As a result, recommendations on surface measurements have been proposed.The effect of different process options (secondary parameters) are also studied in order to better understand the generation of the side surface and optimize it. This study showed that compensations and contour settings are key parameters that can help reduce the side surface roughness. Indeed, the geometric positioning of the different weld tracks is an important issue that must be addressed to reduce surface roughness. Based on the results of this study, it is possible to reduce the average surface roughness Sa from 40 to 10 μm.Finally, this thesis presents a new approach to modeling side surfaces roughness (at 0°). The approach is based on the weld track geometry (radii of curvature). It allows to take into account the weld tracks and layers position in relation to each other and thus to predict the roughness for different scanning strategies, compensation parameters
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32

Qin, Feili. "Metal Oxide Reactions in Complex Environments: High Electric Fields and Pressures above Ultrahigh Vacuum." Thesis, University of North Texas, 2005. https://digital.library.unt.edu/ark:/67531/metadc4843/.

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Metal oxide reactions at metal oxide surfaces or at metal-metal oxide interfaces are of exceptional significance in areas such as catalysis, micro- and nanoelectronics, chemical sensors, and catalysis. Such reactions are frequently complicated by the presence of high electric fields and/or H2O-containing environments. The focus of this research was to understand (1) the iron oxide growth mechanism on Fe(111) at 300 K and 500 K together with the effect of high electric fields on these iron oxide films, and (2) the growth of alumina films on two faces of Ni3Al single crystal and the interaction of the resulting films with water vapor under non-UHV conditions. These studies were conducted with AES, LEED, and STM. XPS was also employed in the second study. Oxidation of Fe(111) at 300 K resulted in the formation of Fe2O3 and Fe3O4. The substrate is uniformly covered with an oxide film with relatively small oxide islands, i.e. 5-15 nm in width. At 500 K, Fe3O4 is the predominant oxide phase formed, and the growth of oxide is not uniform, but occurs as large islands (100 - 300 nm in width) interspersed with patches of uncovered substrate. Under the stress of STM induced high electric fields, dielectric breakdown of the iron oxide films formed at 300 K occurs at a critical bias voltage of 3.8 ± 0.5 V at varying field strengths. No reproducible result was obtained from the high field stress studies of the iron oxide formed at 500 K. Ni3Al(110) and Ni3Al(111) were oxidized at 900 K and 300 K, respectively. Annealing at 1100 K was required to order the alumina films in both cases. The results demonstrate that the structure of the 7 Å alumina films on Ni3Al(110) is k-like, which is in good agreement with the DFT calculations. Al2O3/Ni3Al(111) (γ'-phase) and Al2O3/Ni3Al(110) (κ-phase) films undergo drastic reorganization and reconstruction, and the eventual loss of all long-range order upon exposure to H2O pressure > 10-5 Torr. Al2O3/Ni3Al(110) film is significantly more sensitive to H2O vapor than the Al2O3/Ni3Al(111) film, and this may be due to the incommensurate nature of the oxide/Ni3Al(110) interface. STM measurements indicate that this effect is pressure- rather than exposure- dependent, and that the oxide instability is initiated at the oxide surface, rather than at the oxide/metal interface. The effect is not associated with formation of a surface hydroxide, yet is specific to H2O (similar O2 exposures have no effect).
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Awe, Thomas J. "Experimental investigation of the properties and phase state of thick aluminum surfaces pulsed to megagauss level magnetic field in a Z-pinch geometry." abstract and full text PDF (UNR users only), 2009. http://0-gateway.proquest.com.innopac.library.unr.edu/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3387802.

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34

Blank, Christa, Veneta Hein, Michael Thieme, Hartmut Worch, Susanne Höhne, and Frank Simon. "Ultrahydrophobe chitosanstabilisierte Composite-Schichten auf Aluminiumwerkstoffen." Saechsische Landesbibliothek- Staats- und Universitaetsbibliothek Dresden, 2013. http://nbn-resolving.de/urn:nbn:de:bsz:14-qucosa-108237.

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Selbstreinigende, ultrahydrophobe Oberflächen lassen sich in der Technik vielfältig einsetzen. Das ultrahydrophobe Verhalten beruht einerseits auf einer Rauigkeit im μm-Bereich und andererseits auf der chemischen Zusammensetzung der Oberfläche. Durch den gegebenen Oberflächenaufbau sind derartige Materialien jedoch empfindlich gegen Verschleiß. In diesem Beitrag wird ein Schichtverbund bestehend aus Aluminiumoxid und zwei polymeren Komponenten vorgestellt. Die Aluminiumoxidschicht wird auf dem Wege der anodischen Oxidation erzeugt. Dieses seit langem bekannte Verfahren ermöglicht nicht nur die Oxidation der Aluminiumoberfläche, sondern gestattet es, auch, definierte Oberflächenprofile einzustellen. Durch den gezielten Einbau des hochmolekularen Polymers Chitosan in die mikroprofilierte Aluminiumoxidschicht wurde eine mechanische Stabilisierung der Schicht im Sinne eines anorganisch-organischen Composites erreicht. Außerdem dienten die Amino-Seitengruppen des Chitosans als reaktives Interface für die notwendige chemische Hydrophobierung und als Reaktionszentrum für Vernetzungen, wodurch eine weitere mechanische Stabilisierung bewirkt wird. Der Schichtaufbau hat wesentlichen
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35

Dorenkamp, Yvonne Jeannette. "Inelastic H-Atom scattering from ultra-thin films." Doctoral thesis, Niedersächsische Staats- und Universitätsbibliothek Göttingen, 2018. http://hdl.handle.net/11858/00-1735-0000-002E-E49B-7.

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36

Acosta, Roberto I. "Ostwald Ripening of Iron (Fe) Catalyst Nanoparticles on Aluminum Oxide Surfaces (Al2O3) for the Growth of Carbon Nanotubes." Wright State University / OhioLINK, 2010. http://rave.ohiolink.edu/etdc/view?acc_num=wright1263485314.

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37

Toussaint, Patrick. "Contribution à l'étude de la formation de la couche d'inhibition de l'acier galvanisé en continu." Doctoral thesis, Universite Libre de Bruxelles, 1997. http://hdl.handle.net/2013/ULB-DIPOT:oai:dipot.ulb.ac.be:2013/212205.

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Un simulateur de laboratoire de galvanisation continue a été conçu et utilisé pour l'étude des effets des paramètres de contrôle du procédé sur la prise d'aluminium interfacial avec un intérêt particulier porté té à la simulation de l'hydrodynamique de l'écoulement du liquide à la surface de la tôle ainsi qu'aux durées d'immersion extrêmement courtes inférieures à une seconde. Les effets de la concentration en aluminium et des températures de travail ont aussi été étudiés. Il a pu être montré que la prise d'aluminium est extrêmement rapide dans les premiers instants de la réaction et que la couverture complète de l'acier par la couche d'inhibition était assurée après le premier dixième de seconde. La réaction se poursuit avec une vitesse de croissance de la couche compatible avec la diffusion à l'état solide du fer à travers le produit formé. Un modèle mathématique décrivant les phénomènes est proposé. La microscopie de force atomique a été utilisée pour l'étude de la morphologie de la couche d'inhibition et la microanalyse X à sélection d'énergie pour la mesure de son épaisseur.


Doctorat en sciences appliquées
info:eu-repo/semantics/nonPublished

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38

Santana, Victor Mancir Da Silva. "Contribuição ao estudo da função dielétrica de superfície por espectroscopia de perda de energia de fotoelétrons induzidos por raios-X (XPS-PEELS)." Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1S024/document.

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Cette étude, expérimentale et théorique, de physique des surfaces développe une méthode basée sur la spectroscopie de perte d'énergie des photoélectrons, pour déterminer les propriétés électroniques d'un matériau à partir de mesures XPS. Sur la base de la physique de la photoémission dans un solide homogène, la technique XPS-PEELS donne accès à la fonction de perte d'énergie ELF(E, q) liée à la partie imaginaire et la fonction diélectrique sur une large plage d’énergie (environ 50 eV) avec une sensibilité typique de ≈ 5 nm en profondeur. Dans les métaux ou les semi-conducteurs à faible gap, qui présentent un chevauchement important entre le pic quasi-élastique ZLP(E) et la région des pertes d'énergie, la technique est rendue applicable par la méthode de transformée de Fourier développée dans cette thèse. Les distributions en énergie de la source de rayons X et de la fonction d’appareil sont directement mesurées. La forme asymétrique du pic quasi-élastique ZLP(E) est obtenue à partir de la densité d’états électroniques (calcul par une méthode DFT), à l’aide du modèle de Hopfield-Wertheim-Citrin décrivant la réponse des électrons de valence à la création du trou (théorie multi-corps). L'algorithme XPS-PEELS utilise l'ensemble du spectre sans soustraction empirique d’une ligne de base. Il considère deux types d'excitations de plasmon - intrinsèques et extrinsèques - avec des taux de création différents mais impose la même distribution en énergie. Cette méthode originale permet d’accéder à des excitations électroniques de faible énergie (pertes proches du pic XPS) ; dans le cas de l'aluminium métallique, la transition inter-bandes est observée à 1.80 eV. En tant que technique de spectroscopie électronique, les effets de dispersion de la fonction de perte ELF(E, q) ont été considérés en utilisant un code TD-DFT (Exciting); quel que soit le niveau d'approximation (RPA, ALDA, LRC), les calculs ne décrivent pas correctement la largeur du spectre ELF expérimental (2.3 eV). À la fin du travail, nous comparons la méthode de la transformée de Fourier avec une méthode empirique d'élimination du pic élastique, valable pour les isolants, dans le cas de l'oxyde d'aluminium Al₂O₃
This surface physics study, experimental and theoretical, develops a technique based on the energy loss spectroscopy of photoelectrons, to determine electronic properties of a material from XPS measurements. Based on the physics of photoemission in a homogeneous solid, the XPS-PEELS technique provides the energy loss function ELF(E, q) related to the imaginary part and the dielectric function with energy extension up to 50 eV and a typical sensitivity of ≈ 5 nm in depth. In metals or low-gap semiconductors, with important overlap between the elastic peak and the energy loss region, the technique became applicable by the Fourier transform method developed in this thesis. In addition to the distribution of the X-ray source and analyzer apparatus function, the asymmetric shape of the no-loss peak ZLP(E) is based on the calculation of the Density of Electronic States (DFT method) and the Hopfield-Wertheim-Citrin model describing the response of valence electrons to the creation of the hole (many body theory). The XPS-PEELS algorithm uses the entire spectrum without any empirical background subtraction. It considers two types of plasmon excitations - intrinsic and extrinsic - with different rates of creation but imposing the same distribution in energy. This original method was applied to the aluminum metal, allowing the analysis of the loss function and revealing interband excitations (1.80 eV) at low energy, very close to the no-loss peak. As an electron spectroscopy technique, dispersion effects of the loss function ELF(E, q) were considered using a TD-DFT code (Exciting); for any level of approximation (RPA, ALDA, LRC), the calculations do not describe properly the high width (2.3 eV) of the experimental ELF. At the end of the work, we compare the Fourier transform method with an empirical method of elastic peak elimination, valid for insulators, in the case of aluminum oxide Al₂O₃
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39

Divin-Mariotti, Synthia. "Texturation micrométrique de surface par procédé mécanique de moletage pour optimiser la tenue mécanique des assemblages collés." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSEC040.

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Dans le domaine de l'aéronautique les ensembles mécaniques sont usuellement assemblés avec des rivets, des vis et des écrous. Ces mécanismes imposent des ajouts de masse importants sur les ensembles mécaniques et des contraintes mécaniques locales. A grande échelle, ces défauts peuvent consommer beaucoup d'énergie pour être compensés. En plus de l'arrivée croissante de matériaux composites pouvant plus facilement être fragilisés, ces inconvénients ont amené à se pencher vers d'autres moyens d'assemblages dont notamment le collage.Afin d'optimiser les assemblages collés, les surfaces peuvent être fonctionnalisées. Fonctionnaliser une surface permet de lui apporter des propriétés spécifiques. La texturation de surface fait partie des méthodes de fonctionnalisation des surfaces. Texturer une surface permet de changer ses propriétés chimiques et/ou de changer sa morphologie. Ainsi, de nombreuses surfaces innovantes ont été créées comme par exemple des surfaces à forte adhésion inspirées des pattes de geckos. S'inspirer de surfaces à forte adhésion est intéressant dans le cadre des assemblages collées.Les travaux présentés dans ce manuscrit ont pour objet la texturation de surfaces en aluminium par procédé mécanique de micro-moletage pour augmenter la tenue d'assemblages collés. La démarche utilisée a été dans un premier temps de déterminer des paramètres de forme de motifs de texturation favorables à une meilleure adhésion de la colle et donc à une surface à caractère hydrophile à l'aide de mesures de topographie de surface et de mouillage. Dans un second temps, l'adhésion de deux types de texturations a été caractérisée. Ainsi, les procédés de texturation par laser femtoseconde et par micro-moletage ont été comparés en analysant la physico-chimie de surfaces texturées grâce à des mesures de mouillage et d'XPS. Enfin, l'adhérence des surfaces texturées par plusieurs procédés de texturation a été déterminée avec des mesures de flexion trois points
In aerospace study, mechanical assemblies are usually made by riveting, srew and nuts. Those assemblies are then heavy, long of installation, unsightly, with heterogen mechanical stress. Nowadays with the development of improved materials properties with composites those processes are not optimized. So glued joints are a good candidate.In order to optimize glued assemblies, surfaces can be functionalized. Surface functionalization allows specific surfaces properties. Surface functionalization can be obtained thanks to surface texturing, one of the surface functionalization methods. Surface texturing can change chemical properties and/or morphology of the material surface. Textured surfaces are interesting for academic and industrial researches. Thus, many innovative surfaces have been created, such as high-adhesion surfaces inspired by geckos' feet.The work presented in this manuscript aims to texture aluminum surfaces by micro-knurling process to increase the mechanical strength of bonded assemblies. The approach developped consisted to determine texturing patterns favorable for better surface adhesion by glue and therefore to a hydrophilic surface thanks to wetting and topographical measurements. Then, the approach was to compare and characterize femtosecond laser and micro-knurling textured surface adhesion, with physico-chemical measurements. Finally, the adhesion of several textured surfaces was analyzed and compared with three points bending measures
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40

Beganovic, Thomas. "Evolution im Aluminium-Guss von Fahrwerk-Komponenten." Doctoral thesis, Technische Universitaet Bergakademie Freiberg Universitaetsbibliothek "Georgius Agricola", 2016. http://nbn-resolving.de/urn:nbn:de:bsz:105-qucosa-216071.

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Werkstoff- und Prozessgrenzen beschränken unter Beachtung ökonomischer und ökologischer Aspekte den Leichtbau gegossener Fahrwerk-Komponenten aus Al-Si-Legierungen. Zunächst werden Bauteilgewicht und Wärmebehandlungsprozess als beeinflussbare Hauptbeitragsleister für Emissionen im Herstellprozess identifiziert. Zu deren Verringerung werden abhängig von der Belastungsart mögliche Mindestwandstärken abgeleitet, die für den Kokillenguss um 35 % reduziert werden. Dies gelingt durch Einsatz neuartiger, das Formfüllverhalten verbessernder Oberflächenstrukturierungen von Gießwerkzeugen bei Einhaltung von Konstruktionsregeln. Die Gesamtprozesszeit der Wärmebehandlung kann bei gleichbleibenden mechanischen Eigenschaften um 40 % verkürzt werden. Dabei erfolgt die Charakterisierung des Werkstoff- und Bauteilverhaltens unter dynamischer Belastung bei Parametervariation, da keine Korrelation zu den statischen mechanischen Kennwerten vorliegt.
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41

Blank, Christa, Veneta Hein, Michael Thieme, Hartmut Worch, Susanne Höhne, and Frank Simon. "Ultrahydrophobe chitosanstabilisierte Composite-Schichten auf Aluminiumwerkstoffen." Technische Universität Dresden, 2007. https://tud.qucosa.de/id/qucosa%3A26746.

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Selbstreinigende, ultrahydrophobe Oberflächen lassen sich in der Technik vielfältig einsetzen. Das ultrahydrophobe Verhalten beruht einerseits auf einer Rauigkeit im μm-Bereich und andererseits auf der chemischen Zusammensetzung der Oberfläche. Durch den gegebenen Oberflächenaufbau sind derartige Materialien jedoch empfindlich gegen Verschleiß. In diesem Beitrag wird ein Schichtverbund bestehend aus Aluminiumoxid und zwei polymeren Komponenten vorgestellt. Die Aluminiumoxidschicht wird auf dem Wege der anodischen Oxidation erzeugt. Dieses seit langem bekannte Verfahren ermöglicht nicht nur die Oxidation der Aluminiumoberfläche, sondern gestattet es, auch, definierte Oberflächenprofile einzustellen. Durch den gezielten Einbau des hochmolekularen Polymers Chitosan in die mikroprofilierte Aluminiumoxidschicht wurde eine mechanische Stabilisierung der Schicht im Sinne eines anorganisch-organischen Composites erreicht. Außerdem dienten die Amino-Seitengruppen des Chitosans als reaktives Interface für die notwendige chemische Hydrophobierung und als Reaktionszentrum für Vernetzungen, wodurch eine weitere mechanische Stabilisierung bewirkt wird. Der Schichtaufbau hat wesentlichen
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42

Souza, Ulisses Miguel de. "Produção de uma liga AlNi por refusão com laser." [s.n.], 2001. http://repositorio.unicamp.br/jspui/handle/REPOSIP/263610.

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Orientador: Maria Clara Filippini Ierardi
Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecanica
Made available in DSpace on 2018-07-29T03:11:52Z (GMT). No. of bitstreams: 1 Souza_UlissesMiguelde_M.pdf: 6146675 bytes, checksum: a098d7fa360e3318b0d61cda9715b8af (MD5) Previous issue date: 2001
Resumo: O laser atualmente é uma eficiente ferramenta para tratamentos de superficie, atingindo uma área restrita, ou seja, alterando propriedades das regiões superficiais sem alterar o material como um todo. Dentre os tratamentos superficiais com laser pode citar-se a Formação de ligas de Superficie (Alloying) e o Formação de Ligas de Camadas Superficiais (Cladding). Esses processos, em função da pequena área afetada pelo calor, propiciam condições para a solidificação rápida, favorecendo precipitação de fases fora do equilíbrio e refino de grão. Essas alterações superficiais podem melhorar a resistência ao desgaste e dureza. O presente trabalho analisa o processo de Formação de ligas de Superficie (Alloying) de uma liga AI Ni sobre substrato de alumínio comercialmente puro. A nova liga de superficie formada é avaliada através da análise da microestrutura resultante, dureza, variação da concentração de Ni na camada e resistência à corrosão
Abstract: Nowadays the laser is an efficient toa} to treat surfaces, getting to a restricted area by altering the propertie~ of thore &lperncial area~, without altering the ma.terial a.~ a. whole. Among~t the superficial laser treatments one can menrion Alloying and Cladding. These processes, because of the small heat affected area, allow conditions to a rapid solidification, favoring the precipitation of phases out of equilibrium and grain refinement. These surface alterations can increase the resistance to wearing and the hardness. The present work analyses the laser AIloying of a AlNi compound over a commercially pure AI substrate. The newly formed surface compound is evaluated by an analysis of the resulting microstruture, porosity, hardness, variation of the Ni concentration in the layer and resistance to corroslon
Mestrado
Materiais e Processos de Fabricação
Mestre em Engenharia Mecânica
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43

Desrousseaux, Camille. "Prévention de l'adhésion bactérienne et du développement du biofilm sur les dispositifs médicaux de la perfusion via les surfaces nanostructurées." Thesis, Clermont-Ferrand 1, 2015. http://www.theses.fr/2015CLF1PP03.

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Les infections nosocomiales liées aux dispositifs médicaux, et plus particulièrement ceux de la perfusion, sont un problème majeur dans le milieu hospitalier. Ces infections sont liées à la présence de biofilm. Pour lutter contre le biofilm, les mesures préventives en hygiène ne sont pas suffisantes. Les recherches se dirigent vers la modification des surfaces des matériaux des dispositifs médicaux: ajout de substances biocides, développement de surfaces antiadhésives par voie chimique ou topographique. L’objectif de cette thèse est de créer des polymères nanostructurés pouvant entrer dans la composition de dispositifs médicaux de la perfusion et de tester leur impact sur l’adhésion bactérienne et le développement du biofilm. Dans un premier temps, la technique de nanostructuration choisie repose sur la réplication d’un moule nanostructuré en alumine nanoporeuse qui se caractérise par des nanopores auto-organisés en nid d’abeille. Après avoir mis en place une station d’anodisation permettant la nanostructuration de ce moule, la reproductibilité du procédé de fabrication a été validée (diamètre des pores : 51 ± 6 nm, profondeur: 97 ± 9 nm, espace interpores: 102 ± 6 nm). Ensuite, les travaux de réplication ont été effectués avec le polymère ABS (acrylonitrile-butadiène-styrène). Plusieurs méthodes de réplication ont été testées à partir de dépôt de solutions de polymères ou de fonte du matériau sur le moule d’alumine. La méthode sélectionnée sur des critères de reproductibilité et de facilité de transposition industrielle donne des nanostructures de type nanopicots (diamètres des picots : 56 ± 7 nm, distances interpicots : 101 ± 16 nm, longueurs : 73 ± 33 nm). Les surfaces développées sont ensuite caractérisées (MEB, DSC analyse calorimétrique différentielle, spectrométrie Infra Rouge, angle de contact). La fabrication des nanostructures ne semble pas dégrader le matériau ABS et la modification topographique rend la surface plus hydrophile. Une étude de stabilité montre que les nanostructures résistent à plusieurs modes de stérilisation (oxyde d’éthylène, plasma H2O2 et rayon Beta) et sont conservés dans le temps, ce qui les rend applicables à la surface d’un dispositif médical. La seconde étape du travail consiste à évaluer l’adhésion bactérienne sur les surfaces témoins et nanostructurées. Différents tests de culture de biofilm ont été réalisés avec S. epidermidis en conditions statique ou dynamique. Après un temps de 3 à 48h, les bactéries sont décrochées de la surface puis dénombrées sur gélose. Il n’y a pas de différence significative d’adhésion bactérienne entre les deux types de surface. L’observation en microscopie électronique à balayage et confocale à 24h semble confirmer ce résultat. Des tests réalisés avec d’autres souches bactériennes (S. aureus, K. pneumoniae, P. aeruginosa) en condition statique montrent également que l’adhésion est également identique sur les deux surfaces. Par conséquent, nous pouvons conclure que nos surfaces ABS développées avec ces nanopicots spécifiques n’ont pas un effet anti-adhésion sur les bactéries testées. Des recherches récentes mettent en évidence que l’espacement entre les nanopciots est un facteur critique sur l’adhésion bactérienne. L’étape suivante de notre travail consiste à tester de nouvelles nanostructures réalisées avec un moule AAO ayant une distance interpore plus grande
Medical device-related infections are a public health concern and an economic burden. The role of biofilms in medical device-related infections is clearly established. Preventive hygiene measures are not often sufficient to prevent biofilms formation. One promising way of preventing device-related infections is the development of medical devices with surfaces or materials that reduce either microbial viability using biocidal substances or microbial adhesion with topographical modifications.Developing nanostructured polymeric surfaces, which could have applications in medical devices, and testing their impact on bacterial adhesion and biofilm development were the main goals of this thesis. First of all, the polymer was replicated on an aluminum anodized oxide nanostructured mold (AAO), characterized by highly ordered nanopores. An anodization station was made in order to create molds. Then, the reproducibility of the process fabrication was validated (pore diameter: 51 ± 6 nm, deepness 97 ± 9 nm, interpore espace: 102 ± 6 nm). Several replication techniques with ABS were tested including polymers solutions and melted polymers. The selected method was the one with the most reproducible results pillar diameter: 56 ± 7 nm, interpillar distance: 101 ± 16 nm, length: 73 ± 33 nm) and the most representative of industrial injection processes. The created surfaces were then characterized (MEB, DSC, ATR-FTIR, wettability). The fabrication process does not seem to degrade the ABS material and the topographical change increases the hydrophilicity of the surface. A stability study showed that the nanopillars were resistant to several sterilization processes (ethylene oxide, H2O2 plasma, Beta irradiation) and were maintained through time, which is an important element for applications in medical-devices.The second step of our work consisted of assessing bacterial adhesion on control and nanostructured ABS samples. Several biofilm tests were made with S. epidermis in static and dynamic conditions. Between 3 and 48 hours of culture, bacteria were removed from the surfaces and then viable plate counting was performed. No significant differences were observed between the samples. Microscopic observations (MEB, CSLM) seemed to confirm this result. Other bacteria with different morphologies were tested (S. aureus, K. pneumoniae, P. aeruginosa): bacterial adhesion was similar for the two surfaces. Therefore, we can conclude that our developed ABS surfaces with these specific nanopillars do not have an anti-adhesion effect on the tested bacteria. Recent researches showed that spacing between nanopillars is a critical factor on bacterial adhesion. The following step of our work would be to test new nanostructures using AAO molds with bigger interpore distance
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44

Beak, Douglas Gerald. "Lead and arsenic speciation and bioaccessibility following sorption on oxide mineral surfaces." Columbus, Ohio : Ohio State University, 2005. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=osu1131933545.

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45

Gustafsson, Sofia. "Corrosion properties of aluminium alloys and surface treated alloys in tap water." Thesis, Uppsala universitet, Institutionen för materialkemi, 2011. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-157527.

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The aim of this thesis is to obtain a basic knowledge of the factors that affect corrosion of aluminium in tap water for different kinds of applications like water pipes for tap water, solar systems, HVAC&R-applications (like fan coil units on chillers) and heat sinks for electronic or industrial applications. Open systems are used in some applications and closed systems in others. There is a clear difference in the corrosion behaviour of these two systems. The main reasons for this difference are that the content of oxygen differs between the two systems and also that inhibitors can be used in closed systems to hinder corrosion. In this thesis focus will be on corrosion in open systems. The corrosion properties in tap water for different alloys of aluminium and different surface treatments have been examined. The influences on corrosion of the oxygen content in water and the iron content in aluminium alloys have been investigated. The corrosion properties of an aluminium alloy in deionised water have also been examined.
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46

Stollberg, David Walter. "Nanoindentation of YSZ-alumina ceramic thin films grown by combustion chemical vapor deposition." Diss., Georgia Institute of Technology, 2000. http://hdl.handle.net/1853/43977.

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Combustion chemical vapor deposition (combustion CVD) is a thin film deposition process that uses a flame created by the ignition of an aerosol containing precursors dissolved in a flammable solvent. Combustion CVD is a relatively new technique for creating thin film oxide coatings. Combustion CVD has been successfully used to deposit high quality thin oxide films for potential applications such as thermal barrier coatings, dielectric thin films, composite interlayer coatings, etc. The present work involved developing the optimum parameters for deposition of thin films of yttria-stabilized zirconia (YSZ), alumina (Al₂O₃), and YSZ-alumina composites followed by a determination of the mechanical properties of the films (measured using nanoindentation) as a function of composition. The optimized parameters for deposition of YSZ, alumina, and YSZ-alumina composites onto single crystal a-plane alumina involved using an organic liquid as the flammable solvent and Y 2-ethylhexanoate, Zr 2-ethylhexanoate and Al acetylacetonate as the metal precursors at a 0.002 M concentration delivered at 4 ml/min at flame temperatures of 155 ℃ and substrate temperatures of 105 ℃. The resulting films were grown with deposition rates of ~ 1.5 μm/hr. Measurement of the mechanical properties (hardness, elastic modulus and fracture toughness) of the films was performed using a mechanical properties microprobe called the Nanoindenter®. In order to obtain valid results from nanoindentation, the combustion CVD films were optimized for minimum surface roughness and grown to a thickness of approximately 0.8 μm. With the penetration depth of the indenter at approximately 150 nm, the 800 nm thickness of the film made influences of the substrate on the measurements negligible. The hardnesses and elastic moduli of the YSZ-alumina films did not vary with the composition of the film. The fracture toughness, however, did show a dependence on the composition. It was found that second phase particles of alumina grown into a YSZ matrix increased the fracture toughness of the films (on average, 1.76 MPa• m⁰.⁵ for 100% YSZ to 2.49 MPa• m⁰.⁵ for 70 mol% YSZ/30 mol% alumina). Similarly, second phase particles of YSZ grown into an alumina matrix also increased the fracture toughness (on average, 2.20 MPa• m⁰.⁵ for 100% alumina to 2.45 MPa• m⁰.⁵ for 37.2 mol% YSZ/62.8 mol% alumina). Modeling of the fracture toughness of the YSZ-alumina films was successfully achieved by using the following toughening mechanisms: crack deflection from the second phase particles, grain bridging around the particles, and residual stress from the CTE mismatch between the film and the substrate and between the second phase particles and the matrix of the film.
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47

Gravil, Peter Anthony. "Dynamics of aluminium surfaces." Thesis, University of Liverpool, 1994. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.240749.

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48

André, Bérangère. "Structure et réactivité de poudres d’aluminium nanostructurées." Thesis, Aix-Marseille, 2013. http://www.theses.fr/2013AIXM4301.

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Les poudres d'aluminium sont depuis longtemps utilisées comme additifs dans de nombreuses formulations pour la pyrotechnie ou les propergols. Introduites en quantité relativement faible dans les propergols des fusées, elles permettent d'accroître significativement les vitesses de combustion. Cependant, les mécanismes à l'origine de cette meilleure réactivité restent encore mal compris et vont bien au-delà d'une simple explication en terme d'augmentation de l'état de division. Au cours de cette thèse nous avons élaboré des poudres d'aluminium par broyage à haute énergie, technique mécanique peu couteuse qui pourrait être une alternative aux procédés de fabrication actuels. Nous montrons que cette méthode permet l'obtention de particules micrométriques ou nanométriques suivant les conditions de broyage. Les particules sont polycristallines et présentent une morphologie en plaquette. Les poudres nanométriques obtenues présentent une réactivité comparable voire même supérieure aux nanopoudres sphériques actuellement élaborées par électro-explosion de fil ou voie plasma. Nous montrons que cette bonne réactivité est lié à la morphologie des particules ainsi qu'à la microstructure de la couche d'alumine native qui passive l'aluminium
Aluminium nanopowders have been using for a long time as additives in many formulations for propergol or in pyrotechnics. Introduced in small quantity in rocket propergol they allow to increase the combustion rate. However, the reactivity of aluminium particles is not really understood and not just linked to the size reduction effect. All along this study, we have elaborated aluminium powders using high energy mechanical milling, a mechanical technique with a low cost which could be an alternative process of powders fabrication. We prove that this method allows elaboration of micro and nano-particles as a function of the mechanical parameters. The particles are polycristallines with flake morphology. The obtained nanopowders have a similar reactivity, or better than spherical nanopowders obtained by wire electrical explosion or plasma. We proove that this good reactivity is linked to the particles morphology, as well as also to the microstructure of the native alumina core shell
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49

Wilson, G. R. "Surface studies of aluminium and aluminium alloys." Thesis, University of Newcastle Upon Tyne, 1987. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.377646.

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50

Pélissier, Krystel. "Étude des mécanismes d'adhésion entre une surface d'oxyde et hydroxyde métallique (modèle et industrielle) et un polymère type époxy. Caractérisation de l'interface et de l'interphase." Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0067.

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La nouvelle génération de revêtement métallique à base de zinc, aluminium et magnésium (ZM) développée par ArcelorMittal permet une meilleure résistance à la corrosion pour une épaisseur plus faible que les aciers galvanisés standard du type GI. Toutefois, leur homologation pour l’utilisation dans des assemblages collés dans le secteur automobile pose problème car, contrairement au système adhésif crash/GI, des ruptures adhésives sont observées lors du test de traction-cisaillement d’un assemblage adhésif crash/ZM. Ce travail a visé à comprendre la ou les raison(s) de ces ruptures adhésives afin de proposer des solutions industrielles pour y remédier. Pour cela, une stratégie multi-technique et multi-échelle (XPS, IRRAS, Raman, AFM, …) a été mise au point afin de caractériser la surface métallique et ses oxydes, les interactions de ces derniers et les composants réactifs de l’adhésif à savoir la résine (DGEBA) et le durcisseur (DDA), et le système complet adhésif/ZM. Nous avons montré que la chimie de surface du ZM est bien plus complexe que celle du GI et est dominée par des phases riches en magnésium et très peu par des oxydes/hydroxydes de zinc contrairement au GI d’où une réactivité différente vis-à-vis de la DGEBA et la DDA. En particulier le piégeage de la DDA par interaction avec le magnésium perturbe la réticulation dans une interphase chimique ainsi que l’interaction du réseau polymérique avec la silice colloïdale et les charges à base de calcium dans une interphase mécanique affaiblissant la mécanique d’ancrage de l’adhésif. Divers solutions telles que l’application d’un traitement de surface sont proposées pour remédier à cet effet négatif du magnésium
New generation of metallic coatings based on zinc, aluminum and magnesium chemistry (ZM) developed by ArcelorMittal allows a higher corrosion resistance with a thinner layer than standard galvanized steel GI. However, its homologation for bonding structure application in automobile sector is a problem because of observation of adhesive failure after lap shear test with crash adhesive unlike GI coatings. This work’s aim is to understand the reason(s) behind the adhesive failure in order to resolve this problem by proposing industrial solutions. Thus, a multi-technical and multi-scale strategy (XPS, IRRAS, Raman, AFM,… ) was developed to characterize the metallic surface and its oxides, interactions between these oxides and the reactive components of the adhesive, namely the epoxide resin (DGEBA) and the hardener (DDA) and finally the whole system, i.e. ZM/adhesive. It was demonstrated that ZM surface chemistry is far more complex than GI surface chemistry and is dominated by rich magnesium phases and low in zinc oxides/hydroxides unlike GI leading to a different reactivity towards DGEBA and DDA. In particular, the DDA trapping by interaction with magnesium disrupts reticulation process in a chemical interphase and interaction of the polymeric network with colloidal silica and mineral fillers (calcium types) in a mechanical interphase which is weakening the adhesive mechanical anchoring. Several solutions like application of surface treatments can be proposed to solve the negative effect of magnesium
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