INTECINCONICETUBAFacultad de Ingenieria

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Mechanical Engineering | Advanced Materials

Advanced Materials

Materials Laboratory. Department of Mechanical Engineering.
Engineering Faculty. University of Buenos Aires
Paseo Colón 850. (C1063ACV) Ciudad Autónoma de Buenos Aires.
Phone: +54 11 4343 0891 Extension: 381/388
E-mail: gma@fi.uba.ar

Research Field

Metal Alloys and Metal Matrix Composites
Polymers and Polymer Matrix Composites
Ceramic Materials
Renewable Energy Applications

Members

Direction:

Audebert, Fernando Enrique. PhD. Investigador Independiente de CONICET. Profesor Adjunto.

faudebe@fi.uba.ar

__

Cavaliere, Miguel. PhD.

Saporiti, María Fabiana Sonia. PhD.

Fuentes, Federico. Engineer. Ayudante Primero.

Herreño Daza, Ezequiel. Engineer. Becario CONICET.

Pérez, Ezequiel. Engineer.

Pichipil, Marcela. Engineer.

Raith, Eduardo. Engineer.

Juárez, Ricardo. M.S.

Rozenberg, Silvia Mirta. M.S. Profesora Adjunta.

srozen@fi.uba.ar

Bassi, Facundo.

Berdón, Amadeo.

Binora, Bruno.

Di Pace, Martín. Tesista de grado.

Galdos, Rodrigo.

Galloni, Pablo.

Igarza, Esteban. Estudiante Magíster.

Matti, Federico. Tesista de grado.

Nerini, Carlos.

Ruiz Palero, Martín. Tesista de grado.

Schupbach, Detlev.

Work Description

RESEARCH AND DEVELOPMENT

AREA: Metal Alloys and Metal Matrix Composites

1 - Development of amorphous and nano-structured Aluminum based alloys

This is the main research area of the Advanced Materials Group. The aim is to develop new processes and Aluminum based alloys with improved properties in comparison to current commercial alloys. The research not only involves the strengthening of scientific knowledge but also the development of industrial applications. Modeling techniques, different materials processing methods and a great variety of experimental characterization techniques are used.

Study of the influence of alloying elements on the existing associations in liquid Aluminum alloys

The aim is to understand the effect of alloying elements on the structure of the liquids and also on the solid material obtained by rapid solidification process. Molecular Dynamics simulation and structural analysis of amorphous alloys through various complementary techniques such as Mössbauer spectroscopy, X-ray diffraction, X-Ray Absorption spectroscopy (EXAFS), 3D Atom Probe and High Resolution Electron Microscopy are used. Synchrotron radiation is also employed in collaboration with the University of Oxford.

Nano-quasicrystalline Aluminum based alloys

The knowledge of the effect of alloying elements on the short range order in liquid Aluminum alloys, allows to select the chemical compositions to obtain quasicrystalline nano-particles dispersed in an Aluminum matrix by rapid solidification. These structures are known as nano-quasicrystalline alloys. In particular, the study focuses on those alloys having high mechanical strength at high temperature. With values of mechanical strength of around of 270 MPa at 350 ºC, these alloys exceeds by more than 5 to 6 times the mechanical strength and working temperature range of commercial Aluminum alloys (250 ºC). Thus, the new alloys have a great potential use for novel applications as a better alternative to Titanium alloys. Primary rapid solidification techniques such as Melt-Spinning or gas atomization and plastic forming techniques are used. This research line is developed in collaboration with the University of Oxford and five European and Argentinean companies within a project of industrialization of these alloys.

Hypereutectic Al-Si alloys

Rapid solidification techniques in Al-Si alloys with very high contents of Si (20 to 40%) allow obtaining nano-structured alloys. These alloys have lower density, higher thermal conductivity, lower coefficient of expansion and greater strength than current commercial alloys. These properties make those alloys ideal for demanding applications allowing the design of parts and equipments with less weight, less wear, better durability and performance. Some potential applications are parts of sporting equipment (skis, skates, connectors, clamps and chains, etc.), machine parts and structures (bolts, profiles, guides, cams and benches, etc.) and parts of engines and compressors ( rods, shafts, pistons, valves, stators and vanes, etc.). In particular, mechanical properties and creep behavior of the mentioned alloys are studied. In collaboration with the IAPEL S.A. company these alloys have been used for pistons, which are tested on banks to assess their performance for use in racing cars and luxury vehicles.

Aluminum alloys with amorphous phases

The knowledge of the effect of alloying elements on the cluster association in liquid aluminum allows selecting the chemical compositions to obtain different structures by rapid solidification: amorphous, partially amorphous or the so-called nano-granular amorphous structure. The latter contain granules of nanometric amorphous phase distributed in an Aluminum matrix, which gives them high mechanical strength and corrosion resistance. Corrosion behavior, mechanical properties and the processes to achieve the development of industrial applications are studied. This line is performed in collaboration with the University of Sao Carlos, Brazil.

2 - Development of amorphous and nano-structured Magnesium based alloys

The aim is to develop amorphous and nano-structured Magnesium based alloys using rapid solidification techniques and injection pressure in metal molds. The mechanical strength values obtained in these new alloys reach values up to 650 MPa, which exceeds the values of most of the commercial high strength Aluminum alloys. The studies on these alloys are focused in increasing the glass forming ability as well as in improving the material thermal stability and toughness. A goal is also to improve injection methods and design in the form of nano-composite materials to increase the impact resistance of these novel alloys. The application of methods of injection from the liquid phase of these alloys suggests applications in parts with low thickness. The quality of the surface in the high-pressure injection molded parts avoids the use of further surface finishing processes, which means a substantial cost saving in developing the final product. This line is developed in collaboration with the INTEMA of Mar del Plata and the University of Sao Carlos, Brazil.

3 - Development of metal matrix nano- composites

In order to obtain materials with an optimum combination of properties for a specific application, metal matrix composite materials are developed using different types: metal matrix alloys and new particles / fibers as reinforcements or plasticizerso. Powder metallurgy and plastic forming techniques are generally used. Ceramic particles, carbon nanotubes, metallic glass powders and pure metals are currently used as reinforcement and plasticizers. In the case of pure metals, the production of high toughness and strength plates by rolling processes is analyzed and finite element modeling techniques are also applied. This research line is performed in collaboration with the University of Oxford and the IFW, Leibniz Institute of Dresden. The carbon nanotubes are provided by an Argentinean company.

Pat: "Metal Matrix Composite Material" Ner: PCT/GB2007/004004
Authors: G. W. D. Smith, F. Audebert, M. Galano and P. Grant

4 - Quasi-crystalline coatings for tribological applications

Quasicrystalline phases have high hardness values (700 HV), exceeding that of some hardened steels; they also have low coefficients of friction and lower wettability than crystalline metallic alloys. These properties make these phases of great interest for several tribological applications, such as resistant surfaces to the absorption of organic substances and to abrasive wear. Laser Cladding, Plasma Spray, HVOF and growth of thin films assisted by laser ablation are analyzed to develop these coatings. Interphase problems using different substrate materials such as crystal Si, glass and metallic alloys are also studied. The background in the formation of quasicrystalline surfaces allows the development of specific applications for these wear and adhesion resistant coatings.
In collaboration with an Argentinean company, a new product is developed using these nano-quasicrystalline coatings on aluminum alloys.

5 - Laser processing of Dual-Phase steels

"Dual-Phase" steels exhibit an excellent combination of strength and ductility, but they have low corrosion resistance in some aggressive environments. In order to overcome this disadvantage, the surface structure is modified through surface melting processes by application of laser radiation. With some combination of process variables, surface structures with good resistance to corrosion are obtained. These surfaces have a passivation zone in chloride solutions, as opposed to the continuous solution exhibited by the raw material. This line is developed in collaboration with INTI, the University of Campinas and the University of Salento.

6 - Laser processing of materials for dental implants

Titanium is the most widely used biomaterial in the manufacture of dental implants, due to its bio-compatibility and good mechanical properties. The clinical success of these implants is determined by, among other conditions, the texture and the composition of the film surface that influence the implant-bone interface and, the rate and the quality of the osseointegration. Textures and oxide films on the implants surface are generated with conventional processes such as sandblasting, acid etching, plasma applications and/or thermal treatments. However, the influence of surface features on the optimization of the processes of osseointegration is still a controversial issue. In order to generate textures of different dimensional levels which are also repetitive and controllable, the application of laser radiation is a very interesting approach for the treatment of implant surfaces. The textures achieved so far have shown a 50% increase in the fraction of osseointegrated surface in the experimental model using Wistar rats. This line works in collaboration with the Department of Pathology, Faculty of Dentistry, UBA and the University of Oxford.

7 - Materials bonding by diffusion

Transient liquid phase bonding is applicable in high temperature alloys and nickel alloys for aeronautical use. They are characterized by maintaining a zone with a micro-structure of characteristics and mechanical properties similar to those of the base material to be bonded. This method allows achieve a joint with excellent properties, but due to their long processing time is not applicable for production lines of mass products. Modifications of the bonding process are studied using glassy metals sheets to be employed in the bonding of steels and alloys commonly used in high production lines. This line of work is developed in collaboration with the Laboratory of Amorphous Solids FIUBA and the University of Oxford.


AREA: Polymers and Polymer Matrix Composites

1 - Self-reinforced polymer composites

Due to the limited recyclables of traditional polymer composites, alternative reinforcements have been developed. A promising possibility is to manufacture self-reinforced (all-) polymer composites where the reinforcement is highly oriented, high strength fibers or bands while the matrix is a polymer having same chemical nature but lower melting temperature. In contrast to self-reinforced polymers, between the traditional reinforcement and matrices there are a few orders of magnitude difference in the stiffness and their fracture and failure behavior has been extensively investigated. In order to use self-reinforced polymers in structural or semi-structural applications, a deep knowledge of their mechanical and fracture and failure behavior under different loading conditions is required. In addition to the development and the conventional mechanical characterization of the self-reinforced composites, the aim of this line of research is to study their fracture and failure behavior. Besides the usual mechanical characterization and microscopic analysis, the quasi-static and impact fracture behavior is analyzed, and the failure modes are studied. The effect of loading conditions, distribution of the reinforcement in the matrix and processing conditions on the fracture and failure behavior of different self-reinforced composites is investigated. This line of research is in collaboration with the INTEMA of Mar del Plata and the Department of Polymer Engineering of the Technology and Economics University of Budapest.

2 - Micro and nano-composites based on renewable resources

Environmentally-friendly materials derived from renewable resources are developed. The material properties and their relationship with processing and morphology are studied. Polymer nano-composites using biodegradable matrices reinforced with carbon nanotubes are obtained by electro spinning and thermoplastic polymers reinforced with natural fibers are prepared by extrusion and compression molding. Electrical, viscoelastic, mechanical, thermal and permeability properties are investigated as a function of filler content and different modifications on the matrix and/or the reinforcement. In this line of research, also work people from INTEMA, Mar del Plata, the Polymers and Composites Laboratory, Exacts and Natural Sciences Faculty, University of Buenos Aires and the Polymer Laboratory of the University of A Coruña.

3. Polymer micro and nano-composites with optimal properties

This line of research aims to develop polymer matrix composites with the optimal combination of properties for a specific application. Polypropylene based composites reinforced with rigid particles (alumina, calcium carbonate, silica, quartz, etc.) and polycarbonate composites reinforced with carbon nanotubes are obtained. The material properties (mechanical, rheological, thermal, electrical, etc.) are investigated in order to establish the structure-properties relationship that governs the material final behavior. This research line is developed in collaboration with the INTEMA of Mar del Plata, the Polymer Laboratory of the University of A Coruña, and the Leibniz Institute of Polymer Research, Dresden.

4. In-service behavior of polymers

In-service behavior of polymers used in the Gas and Oil Industry (Polyethylene tubes) and Agriculture (Polyethylene films) is investigated. Laboratory tests are performed to simulate in service conditions such as aging in different solvents, ultraviolet radiation, etc. The evolution of the material properties (mechanical, optical, rheological, etc.) as a function of time is investigated. The different processes involved in the materials aging are identified. The results obtained in laboratory tests are compared with natural aging results. This line is in collaboration with the INTEMA of Mar del Plata, the Plastics Division of INTI and the Department of Mechanics and Mechatronic of the University of Sidney.

AREA: Ceramic Materials

Development of a Ceramic Fuel Cell

Ceramic fuel cells offer the possibility to work with hydrocarbon gases without the need for high purity hydrogen. Due to the expected increase in the future use of biogas, these cells would have a large application for power generation. Although basic designs for these cells are well known, the materials still need improvement in order to enhance their performance and economic feasibility for their mass application. Operation at lower temperatures, better seals to prevent gas loss, and reduction of electrolyte degradation, are some issues to consider. An experimental cell is developed where studies of seals, materials and performance are carried out. Electrolytes are prepared by laser ablation-assisted deposition. In this line of work, people from the Polytechnic of Grenoble, France also collaborate.

AREA: Applications of Renewable Energy

Solar Energy Applications for Drinking Water

Equipment for water purification using solar energy is developed. It is designed to solve the problem of drinking water in isolated rural houses. Different technologies and methods for water purification by removing salts, heavy metals, arsenic and micro-organisms are used. One of the novel techniques is the heterogeneous catalysis technique using TiO2 coatings.

Pat: "Team Solar Water Purification"
Authors: F. Audebert, R. Gordon, G. Soler, M. Rivero González, M.Drainer and E. Ruiz Peace
Ner Patent Application: 2010/0104493 INPI (Argentina)