Adele Carradó

Université de Strasbourg, Institut de physique et chimie des matériaux de Strasbourg (IPCMS), Faculty Member

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Papers by Adele Carradó

Multiscale Simulation Study on the Anisotropic Behavior of Seamless Copper Tubes Processed under Varied Conditions

Journal of Manufacturing Processes, 2020

One of the most important parameters making the production of precision tubes a challenging proce... more One of the most important parameters making the production of precision tubes a challenging process, is the inhomogeneity of mass flow in the pre-stage of processing leading to eccentricity, heterogeneity of residual stresses and crystallographic texture. This paper presents a multiscale modeling framework linking four disparate length scales for studying eccentricity and texture evolution in the tube drawing process with standard as well as tilted dies. The main aim of using this methodology was to comprise the anisotropic elastic and plastic behavior of the material and the crystallographic orientations in the FEM model. This multiscale modeling framework starts with electronic scale calculations using the density functional theory approach to calculate the energy variation as a function of lattice parameters as well as the generalized stacking fault energy for copper. The calculated parameters are bridged to the next simulation scale, the atomic scale calculation. Where molecular dynamics simulations are performed to generate mobilities for dislocations and drag coefficients. The dislocation dynamics approach in the microscale then utilized the mobility values to compute the hardening parameters using the Palm-Voce hardening equation. The use of UMAT subroutine allowed to combine the crystal plasticity theory with the FEM model and calculated elastic and plastic parameters. These last ones were imported to the FEM simulations created for a two-step tube drawing process, performed with standard as well as tilted dies. The simulation results were validated using the measured eccentricity, texture, and mechanical properties: they were in a good agreement with the experimental results.

format_quoteSimulation results using UMAT subroutine effectively validated eccentricity and mechanical properties of tubes against experimental data.format_quote

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Nanocrystalline ?-Al 2 O 3 thin film deposited by magnetron sputtering (MS) at lo

Journal of Coatings Technology and Research, 2010

Harnessing the Multifunctionality in Nature: A Bioactive Agent Release System with Self-Antimicrobial and Immunomodulatory Properties

Advanced Healthcare Materials, 2015

Major problems with biomedical devices in particular implants located in nonsterile environments ... more Major problems with biomedical devices in particular implants located in nonsterile environments concern: (i) excessive immune response to the implant, (ii) development of bacterial biofi lms, and (iii) yeast and fungi infections. An original multifunctional coating that addresses all these issues concomitantly is developed. A new exponentially growing polyelectrolyte multilayer fi lm based on polyarginine (PAR) and hyaluronic acid (HA) is designed. The fi lms have a strong inhibitory effect on the production of infl ammatory cytokines released by human primary macrophage subpopulations. This could reduce potential chronic infl ammatory reaction following implantation. Next, it is shown that PAR, due to its positive charges, has an antimicrobial activity in fi lm format against Staphylococcus aureus for 24 h. In order to have a long-term antimicrobial activity, a precursor nanoscale silver coating is deposited on the surface before adding the PAR/HA fi lms. Moreover, the PAR/HA fi lms can be easily further functionalized by embedding antimicrobial peptides, like catestatin (CAT), a natural host defense peptide. This PAR/HA+CAT fi lm proves to be effective as an antimicrobial coating against yeast and fungi and its cytocompatibility is also assessed. Finally, this all-in-one system constitutes an original strategy to limit infl ammation and prevents bacteria, yeast, and fungi infections.

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Texture gradient in a Cu-tube

Effect of texture on copper seamless precision tubes

METAL MATERIALS PRESENTING A SUPERFICIAL LAYER OF CALCIUM PHOSPHATE, AND METHODS FOR THE PREPARATION THEREOF (54) Title (FR): MATÉRIAUX MÉTALLIQUES PRÉSENTANT UNE COUCHE SUPERFICIELLE DE PHOSPHATE DECALCIUM, ET PROCÉDÉS POUR LE PRÉPARER

(54) Title (EN): METAL MATERIALS PRESENTING A SUPERFICIAL LAYER OF CALCIUM PHOSPHATE, AND METHODS... more (54) Title (EN): METAL MATERIALS PRESENTING A SUPERFICIAL LAYER OF CALCIUM PHOSPHATE, AND METHODS FOR THE PREPARATION THEREOF (54) Title (FR): MATÉRIAUX MÉTALLIQUES PRÉSENTANT UNE COUCHE SUPERFICIELLE DE PHOSPHATE DE CALCIUM, ET PROCÉDÉS POUR LE PRÉPARER (57) Abstract: (EN): The present invention relates to a multilayered material comprising a substrate of metal or metal alloy, said metal or metal alloy substrate being coated in an intermediate layer comprising at least one ceramic element, crystalline structure or partially crystalline structure, said element or structure including a metal or a metal alloy, said intermediate layer being coated in a layer of calcium phosphate comprising an alveolar nanometric structure at the surface, and uses thereof. The present invention relates to the method for preparing such a material by means of autocatalytic deposition of a layer of calcium phosphate comprising an alveolar nanometric structure at the surface thereof.

A safe method for Autocatalytic phosphate deposition on TAV metallic alloy 810 /5/ 2010 Submitted 17-5-2010 accepted 17-3---2013 Number17-502919 - 12 -2013 Registered in France as International Patent

A method was developed to coat biomedical alloys by Autocatalytic biosimulated method which has a... more A method was developed to coat biomedical alloys by Autocatalytic biosimulated method which has advantage of application to complicated shapes ,without adverse effect of heating besides being cost effective. Autocatalytic technique was previously applied for polymeric materials but non for metallic or alloy surfaces. Additionally , the Biomimetic coating process is one of the most promising techniques for producing a layer having mineral and morphology of bone-like hydroxyapatite the main component of bone in living creatures .The procedure followed three baths with different chemical composition , pH values , time and temperatures to coat the heat treated alloys .This was followed by the biomimetic coating process by immersion in prepared simulated body fluids.

Einfluss der Vorrohr-und Auslaufführung auf die Exzentrizität und Eigenspannungen von Rohren beim Gleitziehen

Bei der Herstellung von Rohren erlaubt die Verringerung von Wanddickenschwankungen, die durch die... more Bei der Herstellung von Rohren erlaubt die Verringerung von Wanddickenschwankungen, die durch die Rohrexzentrizität beschrieben wird, Materialeinsparungen und damit – für materialkostenintensive Werkstoffe - interessante Kosteneinsparungen. Je höher man die Anforderungen an die Maßhaltigkeit und je weiter man in den Toleranzvorgaben eingeschränkt wird, desto stärker müssen korrigierende Mechanismen in Anspruch genommen werden, die sich direkt auf die Werkstoffeigenschaften und nicht zuletzt auf die lokale Eigenspannungsverteilung auswirken, desto stärker lokalisieren sich ihre Auswirkungen und umso wichtiger wird ihre Quantifizierung. Die Verringerung des Materialeinsatzes bei gleichem Nutzwert eines Produktes ist bei der Fertigung von Rohren in erster Linie mit der Erreichung geringerer Fertigungsschwankungen verbunden. Durch eine Verringerung der Streubreite des Prozesses beziehungsweise des zu erzeugenden Produktes wirkt sich das bei der Auslegung von Konstruktionen auf die Siche...

Forming Potential of Low-Density Laminates

Metal/polymer/metal sandwich laminates show a rising rate in a variety of applications, for insta... more Metal/polymer/metal sandwich laminates show a rising rate in a variety of applications, for instance in automotive and aircraft industry. Due to the dissimilarity between the metal skin sheets and the polymer core, characterizing the forming potential of such laminates is a necessity. In this study, steel skin sheets and polypropylenepolyethylene copolymer as core sheet – called sandwich laminates - were used. They were produced in a roll bonding process using an adhesive agent. One major research point in IMET is investigating the effect of core and skin thicknesses on the forming behavior and mechanical properties of the sandwich laminates. Forming behavior is evaluated using deep drawing in addition to determining the forming limit curves (FLC). Bonding strength is evaluated by lap shear tests. Moreover, the durability of the steel/polymer joints are evaluated under hydrothermal ageing conditions following heating/cooling regime cycles. Basically, the mechanical properties were d...

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Precision tube production: Influencing the eccentricity and residual stresses by tilting and shifting

Journal of Materials Processing Technology, 2015

Tube drawing is considered to be one of the most effective and flexible methods to reduce easily ... more Tube drawing is considered to be one of the most effective and flexible methods to reduce easily tube dimensions, to improve the surface finish, and to design mechanical properties. However, during the production of pre-tubes, it is common to obtain a tube which could still remain eccentric despite being reduced during the drawing processes. This eccentricity causes an increase in weight since dimensioning has to be based on the weakest location of the tube. Moreover, high values of residual stresses can exist after the drawing process, which-in the case of tensile stresses-can promote failure of the tube subject to tension loading. In this paper, the effects of tilting the die and shifting the tube on the eccentricity and the residual stresses were experimentally and numerically determined using as-received tubes and after their subsequent processing. The relative eccentricity change was measured for each tilting angle and shifting value. It has been shown that when a tilted die is used, the final eccentricity varies depending on the tilting angle. For example, using an angle of 5 • resulted in a decrease of about 40% compared to the standard condition. By increasing the tilting angle, the surface and sub-surface residual stresses can be decreased. A 3D model using ABAQUS software was developed and verified to describe the evolution of residual stresses and eccentricities.

format_quoteTilting angles show a clear functional relationship with eccentricity change in repeatedly drawn tubes, indicating potential for controlled adjustments.format_quote

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Tube Drawing with Tilted and Shifted Die

60 Excellent Inventions in Metal Forming, 2015

ABSTRACT In order to reduce tubes dimensions, improve their surface finish and obtain requested m... more ABSTRACT In order to reduce tubes dimensions, improve their surface finish and obtain requested mechanical properties, tube drawing is one of the most effective and flexible methods used since centuries. Many parameters influence the results obtained such as tool geometry, friction, drawing force, or the amount of thickness reduction. A lot of investigations have been done studying these effects. A significant effect on the local material’s flow is given by abandoning the pass line during drawing leading to an asymmetric deformation over the circumference of the tube. Tube drawing with a tilted die shows a considerable variation in eccentricity in drawn tubes. A similar strong effect is given by shifting the dies – a guiding die and a die for reduction. A third, very effective possibility is the use of local heating, therewith influencing the flow conditions locally. Using these parameters in a controlled way makes possible to influence eccentricity precisely.

Sandwich material systems: A solution for medical applications?

European cells & materials

Physico-chemical studies of Al2O3 coatings obtained by pulsed laser deposition and magnetron sputtering

Nanocrystalline γ-Al2O3 thin films produced by magnetron sputtering at low temperature

Journal of Coatings Technology and Research

Mechanical properties and forming behaviour of laminated steel/polymer sandwich systems with local inlays – Part 1

Composite Structures, 2014

Steel/polymer/steel sandwich materials (SMs) with varying core thickness were produced using the ... more Steel/polymer/steel sandwich materials (SMs) with varying core thickness were produced using the roll bonding technology. At constant skin thickness, the effect of the core thickness change on the mechanical properties, particularly their specific stiffness and strength, was investigated. Additionally, the SMs were locally reinforced with steel inlays to improve their behaviour against dimension changes or the degradation of the core in case of local loading or joining. The effect of the reinforcement (RE) on the strain distribution under deep drawing conditions was studied. Strains were measured using photogrammetry. To take into account the influence of anisotropy in this sense, an essential anisotropy evaluation was carried out for the SMs to assess their forming behaviour. The results revealed an adequate agreement between the measured mechanical properties of SMs and the estimated values following the rule of mixtures. Up to a core volume fraction of approx. 0.37, the specific stiffness and strength values of the SMs are only slightly reduced compared to the monolithic steel material. The deformation analysis shows a significant influence of the inserted REs on the strain distribution and failure and consequently the position of cracking, occurring at the bottom/edge region in front of the RE.

$Material notation for the different 316/PP-PE/316L combinations and the corre- sponding core volume fraction f. t Refers to the thickness of each constituent. Values underlined highlight the keyword of the sandwich notation; for instance SMs 0.3 denotes or refers to the underlined value of the 0.3 mm core thickness. 3. Results and discussion$

$Fig. 4. (a) Stress—strain curves for 316L, PP-PE and SMs according to Table 1 considering the elastic range in (b); (c) measured and estimated UTS, YS and E values; (d) specific stiffness (E/D) and specific strength (UTS/D) as a function of the core volume fraction f.$

$Tensile test results for 316L and SMs 0.6 at different angles ~ to RD. Gauge length = 80 mm; 3 samples each. With «: angle to RD, e,: elongation at fracture (%), ey: uniform elongation (%). Table 2$

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Forming Limit Diagram of Steel/Polymer/Steel Sandwich Systems for the Automotive Industry

Advanced/Sano, 2014

Steel/polymer/steel sandwich materials (SMs) are considered an innovative substitute to the comme... more Steel/polymer/steel sandwich materials (SMs) are considered an innovative substitute to the commercial steel sheets in the automotive industry due to weight-saving potential and enhanced damping properties. Deep-drawing steel and thermoplastic core are used as the skin and core sheets, respectively. The mono-materials and SMs were characterized via tensile test, deep drawing and flow limit curves (FLC) determination. The mechanical properties of the tested SMs showed a good matching with the mixture rule regardless the skin/core sheet thickness. Varying the skin/core sheet thickness has a remarkable effect on the thinning behavior under deep drawing; the core thickness increases the cracking probability. In case of using SMs with different skin-thickness, it is better to position the thin skin sheet in contact with the punch. The core thickness exhibited no significant effect on the FLC results. The thicker-core SMs are subjected to failure at lower strains in the stretching region of the FLC.

Lightweight titanium/polymer/titanium sandwich sheet for technical and biomedical application

Materialwissenschaft und Werkstofftechnik, 2014

ABSTRACT The development of biocompatible implants is remarkably increased by designing new alloy... more ABSTRACT The development of biocompatible implants is remarkably increased by designing new alloys; mainly on the basis of titanium (Ti) and magnesium (Mg) for permanent and biodegradable alloys, respectively. Polymer-based composite structures were also developed and tested to match the conditions of human bones. In this paper, a sandwich material (SM) approach is introduced to tailor the biomechanical properties, mainly the elastic modulus (E) and the biocompatible properties. The sandwich material is composed of Ti grade 1 (Ti Gr. 1) cover sheets and a polypropylene copolymer (PP-PE) core (PP-polypropylene, PE-polyethylene). An epoxy resin is used as an adhesive agent. This type of sandwich material has the potential to replace commercially used laminates in aerospace and automotive industry in cases of the need of a formable lightweight product, too. The mechanical properties were characterized for different core thicknesses via tensile testing. The mechanical properties exhibited a good matching with the estimated values according to the rule of mixtures. On this basis, sandwich material can be tailored to give the appropriate density, elastic modulus and strength as well by varying the ratio of thickness between the partners. The forming behavior was examined under deep drawing conditions, where the Ti-sandwiches exhibit a good drawing capability; cups can be drawn close to the limits of the mono-metal sheet. 3-[4,5-dimethylthiazol-2-y1]-2,5-diphenytetrazolium bromide (MTT) cell viability assay was used to examine the behavior of human osteosarcoma MG-63 cells on metal and polymer components of sandwich material. Cell viability was much higher for Ti/PP-PE/Ti sandwiches compared to 316L/PP-PE/316L ones.

Reinforced Metal/Polymer/Metal Sandwich Composites with Improved Properties

Materials Fabrication, Properties, Characterization, and Modeling, 2011

The Minerals, Metals & Materials Society (TMS)(2011) Reinforced Metal/Polymer/Metal Sandwich ... more

Press Joining Rolling Process for Hybrid Systems

Key Engineering Materials, 2010

The press joining rolling process used for the production of metal/polymer/metal systems is intro... more The press joining rolling process used for the production of metal/polymer/metal systems is introduced. In the first step three-layer sandwich sheet, 316L/polypropylene- polyethylene/316L (316L/PP-PE/316L) with and without local reinforcement, were processed by roll bonding at approx. 250°C of two steel sheets with a pre-rolled PP-PE - core sheet. Mechanical and forming behaviour of the parts had been investigated by tensile, bending and deep drawing tests. It could be shown that for moderate drawing depths deep drawing behaviour is close to the one of the mono-material.

Production of Customized High-Strength Hybrid Sandwich Structures

Advanced Materials Research, 2010

The production process and the forming behaviour of locally reinforced steel/polymer/steel (316L/... more The production process and the forming behaviour of locally reinforced steel/polymer/steel (316L/PP-PE/316L) hybrid sandwich composite materials (SMS) have been investigated. The effect of simple plate reinforcements with different size, shape and geometry on the forming limits of SMS was studied. As a local reinforcement, the simple solid steel and mesh steel plate inlays with central and edge positions were chosen instead of a polymer core as a sandwich laminate. In order to increase the adhesion properties between the metal and polymer layers, corona discharge and plasma preliminary surface treatments were applied prior to the sandwich production. Both, deep drawing and stretching cup-forming tests were performed in order to analyse the forming behaviour as well as the failure of SMS with and without local inlays subject to different tensile loadings. The influence of the local reinforcement on the bending behaviour was determined by three and four-point bending processes. Stress...

format_quoteSandwich composites show promising formability for automotive applications, indicated by deep drawing test results of metal-polypropylene-metal systems.format_quote

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Adele Carradó

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