Papers Vol. 4 núm. 8 julio-diciembre 2008 by Mauricio Arroyave
Se presenta la implementación de un método para indentar superficies rígidas a nanoescala utiliza... more Se presenta la implementación de un método para indentar superficies rígidas a nanoescala utilizando un microscopio de fuerza atómica (Atomic Force Mi-croscopy–AFM). Esta se basa en el modo de espectroscopia de fuerzas (Force Spectroscopy–FS) que usualmente se encuentra disponible en los AFM, la cual permite generar un movimiento vertical de la punta AFM sin desplazamiento lateral. Se hizo necesario caracterizar la fuerza aplicada por el AFM para producir la indentación a través de la determinación del factor de sensitividad de la viga AFM. Se pudieron obtener curvas de fuerza versus desplazamiento, características de los sistemas para nanoindentación dinámica Depth–Sensing Indentation (DSI), sin embargo estas curvas no son aptas para diagnóstico de propiedades mecánicas por el método de Oliver & Pharr. Fueron generadas huellas de indentación del orden de 1 nm de profundidad sobre silicio poli-cristalino y del orden de 50 nm de profundidad sobre aluminio aleado 6261. Estos resultados son prometedores en apliaciones con materiales de la era de la nanotecnología que deben ser evaluados en dichas escalas.
PACS: 07.79.Lh,34.20.Cf, 07.75.+h
Papers by Mauricio Arroyave
Se depositaron peliculas delgadas de Dioxido de Titanio (TiO2) sobre obleas de Silicio tipo p (10... more Se depositaron peliculas delgadas de Dioxido de Titanio (TiO2) sobre obleas de Silicio tipo p (100) y discos de acero inoxidable 304 mediante la tecnica de Magnetron Sputtering R.F. Para el proceso de deposicion se utilizo un blanco de TiO2 de 99.9% de pureza y Argon 99.999% puro, el tiempo de proceso fue de 2 horas y se utilizo una potencia R.F. de 100W, se produjeron 3 grupos de muestras, modificando el bias en el substrato a 0, -50 y -100 V D.C., los demas parametros se dejaron constantes. Los sustratos fueron caracterizados utilizando AFM y SEM con el fin de comparar las propiedades de estos antes y despues de depositar los recubrimientos; estos tambien fueron caracterizados por XRD y EDS. Los espesores de las peliculas depositadas estuvieron entre 79 nm y 83 nm, por lo cual se considera que el efecto que tuvo la variacion de bias sobre este parametro fue poco apreciable. Los resultados obtenidos en los analisis EDS de los recubrimientos de TiO2 sobre sustratos de silicio confir...
Journal of Physics: Conference Series, 2017
Alumina (Al2O3) thin films were deposited on Si (100) by Magnetron Sputtering in reactive conditi... more Alumina (Al2O3) thin films were deposited on Si (100) by Magnetron Sputtering in reactive conditions between an aluminium target and oxygen 99.99% pure. The plasma was formed employing Argon with an R.F power of 100 W, the dwelling time was 3 hours. 4 samples were produced with temperatures between 350 and 400 °C in the substrate by using an oxygen flow of 2 and 8 sccm, the remaining parameters of the process were fixed. The coatings and substrates were characterized using Atomic Force Microscopy (AFM), Scanning Electron Microscopy (SEM), X-ray diffraction (XRD) and Energy Dispersive Spectroscopy (EDS) in order to compare their properties before and after deposition. The films thicknesses were between 47 and 70 nm. The results show that at high oxygen flow the alumina structure prevails in the coatings while at lower oxygen flow only aluminum is deposited in the coatings. It was shown that the temperature increases grain size and roughness while decreasing the thicknesses of the coatings. © Published under licence by IOP Publishing Ltd
Journal of Physics: Conference Series, 2017
Hydroxyapatite (HA) is a material widely used by the medical community due to its Ca/P ratio is c... more Hydroxyapatite (HA) is a material widely used by the medical community due to its Ca/P ratio is comparable to the Ca/P ratio of bones and teeth, which promotes osteoinduction and osteoconduction processes when in contact with bone tissue, either as volume piece or coating. This work focuses on studying the quality of the commercial HA powder MKnano-#MKN-HXAP-S12 µm, after processing, to obtain sintered compact discs with suitable physical and chemical characteristics for implants applications. The HA powder was processed through calcination, grinding, pressing and sintering to evaluate the effect of such as procedures in the compacts dics quality. The raw powder was characterized by laser diffraction, SEM, XRF, XRD, TGA and DSC while the characteristics of the obtained compact discs were determined by dilatometry and XRD to identify the sintering temperature range, constituent phases, the amorphous content and the crystallinity degree, parameters that allow determining their suitability for implants applications. Although, it was not possible to obtain sintered compacts with the suitable chemical composition and without fractures, this work allowed to identify the parameters that determine the suitability of a HA powder to obtain sintered compacts for medical applications, as well as the characterization protocol that allows the evaluation of such parameters. © Published under licence by IOP Publishing Ltd
In this work is shown an experimental procedure in order to characterize and calibrating one Atom... more In this work is shown an experimental procedure in order to characterize and calibrating one Atomic Force Microscopy (AFM) instrument used for nanodeformation on high stiffness surfaces suh as metals and ceramic materials. Both, scanner and probe active parts of AFM were characterized. The dimensions and morphological of AFM probe was analyzed by Scanning Electron Microscopy (SEM) and the chemical characteristics by Energy Dispersive X-Ray Spectroscopy (EDX). The sensitivity factor of probe was measured by indentation on Diamond surface, then non print is caused since the stiffness is higher in the Diamond. The scanner was characterized by their dinamyc response in scan frecuency and calibrated in scan area with a gold grating of 1 µm of spaced. A thin film of Ti was used for Z calibration in the scanner. Before, the thickness was measured in cross section in SEM. Finally, some indentations on Silicon (elastic) and Aluminium (plastic) were realized. Depth indentations of about 1.2 n...
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Resumen En este trabajo se presenta un metodo alternativo basado en microscopia de modulaci on de... more Resumen En este trabajo se presenta un metodo alternativo basado en microscopia de modulaci on de fuerza (FMM), para la identificaci on de nanogotas producidas en el plasma generado por los spots cat odicos de los arcos en vacio. La t ecnica FMM esta habilitada ...
Microscopy and Microanalysis, 2005
The need of techniques for determining the mechanical properties of thin films, e.g. hardness coa... more The need of techniques for determining the mechanical properties of thin films, e.g. hardness coatings on ion beam treated surfaces has prompted a study of the microindentation hardness technique. The present interest is driven to a good understanding of the adhesion, friction, wear, and indentation processes. In most of the solid-solid interfaces of technological relevance, it occurs contact in many asperities, and this is why the study of fundamental properties of micro-mechanic and tribology of surfaces and interfaces is very important. The recent developments of different microscopic techniques based on tips and force surface devices (i.e. AFM, FM, LFM) allowed investigations of interfacial problems with high resolution and have led to the nanoscale regime the mechanical properties study for a wide spectrum of materials. In this work a method for Young's modulus determination of hard coatings multilayers of TiN/ZrN is evaluated. This method is based on AFM and spectroscopy-f...
Ingeniare. Revista chilena de ingeniería, 2015
Brazilian Journal of Physics, 2004
This work presents a study of multilayered Ti/TiN/TiC thin films obtained using a PAPVD (Plasma A... more This work presents a study of multilayered Ti/TiN/TiC thin films obtained using a PAPVD (Plasma Assisted Physical Vapor Deposition) system by pulsed-arc discharge. For this purpose, a titanium target and a stainless steel substrate were used, placed on the cathode and on the anode, respectively, inside a vacuum chamber. To grow these films, different gases and concentrations were required. Ti is obtained with argon gas, TiN with nitrogen, and TiC with methane, at 2.5 mbar and 5 mm distance between electrodes. By means of X ray diffraction (XRD), the phases present in the film were determined, observing (111), (200), and (100) orientations for both, TiN and TiC. Also, by employing XRD techniques, Titanium Atoms Distance (DTA) was calculated at the interface of TiN and TiC, in order to study the crystallographic match. Energy Dispersive Spectroscopy (EDS) was employed in order to carry out elemental analyses in the materials. These analyses were obtained for 12 keV and 30 keV, observing the effects in the results. Taking advantage of defects generated during the growth of the multilayer, chemical composition maps were carried out, probing the combination of Ti and N in one layer and Ti and C in the other layer. Scanning Electron Microscopy (SEM) technique allowed observing the presence of the multilayer, as well as the measurement of the thicknesses of each layer, which are in the order of nanometers.
Bioinspiration & Biomimetics
The quest for new light-weight materials with superior mechanical properties is a goal of materia... more The quest for new light-weight materials with superior mechanical properties is a goal of materials scientists and engineers worldwide. A promising route in this pursuit is drawing inspiration from Nature to design and develop materials with enhanced properties. By emulating the graded mineral content and hierarchical structure of fish scales of the Arapaima Gigas from the nano to macro scales, we were able to develop bioinspired laminated composites with improved impact resistance. Activated by the addition of nano-particles of Al2O3 and nano-layers of TiN to a thermoplastic fiber substrate, new energy dissipation mechanisms operating at the nanoscale enhanced the energy absorption and stiffness of the bioinspired material. Remarkably, the newly developed materials are easily transferred to the industry with minimum associated manufacturing costs.
Scientia, 2004
RESUMEN Se ha diseñado un equipo multicátodo de tipo industrial, para la producción de películas ... more RESUMEN Se ha diseñado un equipo multicátodo de tipo industrial, para la producción de películas delgadas mediante PAPVD, por la técnica de evaporación por arcos eléctricos pulsados. El equipo se compone de una cámara de vacío, con geometría cilíndrica y dimensiones 1 m de diámetro x 1 m de longitud. Las piezas se localizan en un árbol portamuestras intercambiable que tiene movimiento rotacional planetario. La evaporación se realiza simultáneamente en 8 blancos rotatorios, a través de una fuente de potencia controlada con tecnología IGBT. Todas las variables del proceso son controladas automáticamente.
Palabras claves: fuerza atómica, espectroscopia de fuerzas, nanoindentación.
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Papers Vol. 4 núm. 8 julio-diciembre 2008 by Mauricio Arroyave
PACS: 07.79.Lh,34.20.Cf, 07.75.+h
Papers by Mauricio Arroyave
PACS: 07.79.Lh,34.20.Cf, 07.75.+h