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Ítem Deposition and characterization of duplex treated coating system applied on hot work steel AISI H13(Universidad Simón Bolívar, 201-08-08) Bejarano Gaitán, Gilberto; Arroyave Franco, Mauricio; Gómez Botero, Maryori; Universidad EAFIT. Departamento de Ciencias Básicas; marroya5@eafit.edu.co; Electromagnetismo Aplicado (Gema)AISI H13 steel is widely used for extrusion moulds and other hot work tools fabrication, due to its high toughness, strength and hardness around 56 HRC (Rockwell C) -- However, this steel possesses a relatively low wear resistance, which reduces its life time under high loading conditions -- The aim of this work was to enhance the wear resistance of the steel H13 using the following surface treatments:austenitizing + quenching + tempering (further called “tempering”), tempering and bath nitriding, tempering and coated with chromium nitride (CrN), tempering + bath nitriding + coated with CrN (further called “Duplex coating”) -- The properties of the treated samples were compared with each other in dependence of the made surface treatment -- The coatings were deposited using the r.f. balanced magnetron sputtering deposition technique -- The total thickness of the coatings was maintained at 5 µm, while the thickness of the nitrided zone was approximately 140 µm -- The microstructure and the crystalline phase composition were investigated by Scanning -- Electron Microscopy (SEM) and X-ray diffraction (XRD) technique, respectively -- The hardness and the adhesion of the coatings were determined by micro indentation measurements and the Rockwell indentation test, respectively -- The wear resistance of the coatings was evaluated using ball on disc tests -- The duplex treated samples presented a hardness three order of magnitude higher and showed a wear rate six times smaller than those samples only temperedÍtem Recuperación de la energía radiada por conductores de corriente alterna(Sociedad Colombiana de Física, 2001-06-01) Marulanda, José Ignacio; Universidad EAFIT. Departamento de Ciencias Básicas; Electromagnetismo Aplicado (Gema)Ítem Plasma etching of DLC films for microfluidic channel(2003-01-01) JARAMILLO, JUAN MANUEL; Universidad EAFIT. Departamento de Ciencias Básicas; Electromagnetismo Aplicado (Gema)Ítem Identification by force modulation microscopy of nanoparticles generated in vacuum arcs(Fondo Editorial Universidad EAFIT, 2006-01-01) Arroyave, Mauricio; Universidad EAFIT. Departamento de Ciencias Básicas; Electromagnetismo Aplicado (Gema)Ítem Experimentos en el aula de clase para enseñanza de la física(Sociedad Colombiana de Física, 2006-01-01) J. I. Marulanda; Gómez, Luis A.; Universidad EAFIT. Departamento de Ciencias Básicas; Electromagnetismo Aplicado (Gema)Considerando la importancia de los aspectos fenomenológicos como motivación para elaborar modelos formales en la enseñanza de la física, la experimentación se convierte en un recurso didáctico valioso en este proceso.Ítem Caracterización y calibración de un instrumento AFM utilizado para producir nanodeformación en superficies altamente rígidas(2006-02-01) Arroyave, Mauricio; Universidad EAFIT. Departamento de Ciencias Básicas; Electromagnetismo Aplicado (Gema)Ítem MEJORAMIENTO DEL DESEMPEÑO DE UN SISTEMA DE COMUNICACIONES ÓPTICAS FFH-OCDMA UTILIZANDO REDES DE BRAGG APODIZADAS FUERTES(Sociedad Colombiana de Física, 2006-04-01) Marulanda, José Ignacio; Universidad EAFIT. Departamento de Ciencias Básicas; Electromagnetismo Aplicado (Gema)Publicación Dilation behaviour of asphalt mixtures(Taylor and Francis Ltd., 2006-08-01) Ossa, Edgar Alexander; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de IngenieríaPublicación Compressive Deformation Behaviour of Asphalt Mixtures(Association of Asphalt Paving Technologist, 2006-08-01) Ossa, Edgar Alexander; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de IngenieríaPublicación Failure analysis of a civil aircraft landing gear(PERGAMON-ELSEVIER SCIENCE LTD, 2006-10-01) Ossa, Edgar Alexander; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de IngenieríaÍtem Síntesis de reforzantes carbonosos para materiales compuestos a partir de fibras vegetales colombianas(2007-01-01) JARAMILLO, JUAN MANUEL; Universidad EAFIT. Departamento de Ciencias Básicas; Electromagnetismo Aplicado (Gema)Publicación Spherical indentation behavior of asphalt mixtures(ASCE-AMER SOC CIVIL ENGINEERS, 2007-01-01) Ossa, E.A.; Collop, A.C.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de IngenieríaThe spherical indentation response of a dense bitumen macadam asphalt mixture with two different volume fractions of bitumen binder is investigated both experimentally and via an analytical model. The model for the indentation of bitumen developed by Ossa et al. in 2005, was used to study the spherical indentation behavior of the mixtures with good agreement when compared to experimental results. An extensive experimental study of the monotonic and recovery spherical indentation behavior is reported for a range of temperatures. In line with the predictions of the model, the monotonic indentation response of the mixtures exhibits a power-law dependence on the indentation force. The model is also successful in capturing the indentation recovery behavior of the mixtures. A comparison of the material parameters obtained from uniaxial compression and indentation tests showed that indentation tests can be used in an easy and reliable way to obtain the fundamental asphalt parameters. Further, parameters found from indentation tests implicitly account for the confining conditions generated by the aggregate particles below the indenter. © 2007 ASCE.Publicación Estudio comparativo de las propiedades mecánicas de fibras de vidrio y queratina(2007-09-01) Ossa, Edgar Alexander; Montoya, Carolina; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de IngenieríaPublicación Análisis de falla de la mordaza plana de una prensa hidráulica(IMPRENTA UNIV ANTIOQUIA, 2008-01-01) Ossa, E.A.; Paniagua, M.A.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de IngenieríaThis paper describes the analysis and investigation of the causes of the failure of an hydraulic press jaw face grip. Analysis of the fractured surfaces indicated the creation of cracks due to stress concentrators as a result of defective design. On the other hand, metallographic examination revealed the presence of aligned clusters of primary carbides that along with the stress concentrators induced the premature failure of the grip.Publicación Características de adhesión entre fibras de queratina y poliéster insaturado(IMPRENTA UNIV ANTIOQUIA, 2008-01-01) Paniagua, M.; Ossa, A.; Ruiz, G.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de IngenieríaThis work presents the methods and results employed to find the adhesion characteristics between keratin fibers and unsaturated polyester as matrix material. The fibers were conditioned prior to testing using four different methods in order to establish the effect of these treatments on the adhesion to the matrix by means of i) monofilament pull-out testing, as direct method; and ii) Lamina tensile tests as indirect method to analyze the adhesion in the fracture zone with the help of electron microscopy (SEM).Ítem Diseño de un conversor AC/DC para excitación con pulsos rectangulares de un piezoactuador de PZT(2008-04-01) JARAMILLO, JUAN MANUEL; Universidad EAFIT. Departamento de Ciencias Básicas; Electromagnetismo Aplicado (Gema)Ítem Diseño de un conversor AC/DC para excitación con pulsos rectangulares de un piezopactuador de PZT(2008-04-01) Arroyave, Mauricio; Universidad EAFIT. Departamento de Ciencias Básicas; Electromagnetismo Aplicado (Gema)Publicación Failure analysis of a hydraulic press clamp(IMPRENTA UNIV ANTIOQUIA, 2008-06-01) Ossa, Edgar Alexander; Paniagua, Marco Aurelio; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de IngenieríaThis paper describes the analysis and investigation of the causes of the failure of an hydraulic press jaw face grip. Analysis of the fractured surfaces indicated the creation of cracks due to stress concentrators as a result of defective design. On the other hand, metallographic examination revealed the presence of aligned clusters of primary carbides that along with the stress concentrators induced the premature failure of the grip.Ítem La microscopía de barrido por sondas: Herramienta básica en las nanociencias(Fondo Editorial Universidad EAFIT, 2008-09-01) Arroyave, Mauricio; Universidad EAFIT. Departamento de Ciencias Básicas; Electromagnetismo Aplicado (Gema)Publicación Adhesion characteristics between keratin fibers and unsaturated polyester(IMPRENTA UNIV ANTIOQUIA, 2008-12-01) Paniagua, Marco; Ossa, Alexander; Ruiz, Gladys; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de IngenieríaThis work presents the methods and results employed to find the adhesion characteristics between keratin fibers and unsaturated polyester as matrix material. The fibers were conditioned prior to testing using four different methods in order to establish the effect of these treatments on the adhesion to the matrix by means of i) monofilament pull-out testing, as direct method; and ii) Lamina tensile tests as indirect method to analyze the adhesion in the fracture zone with the help of electron microscopy (SEM).