Materiales de Ingeniería

URI permanente para esta comunidad

https://hdl.handle.net/10784/28128

Busca estudiar las propiedades y características de los materiales, teórica y experimentalmente, para el desarrollo y mejoramiento en las aplicaciones de ingeniería.

Líneas de investigación: Biomateriales; Materiales Compuestos; Materiales De Construcción y Reciclaje De Materiales; Materiales Mecánicos.
Código Minciencias: COL0064861.
Categoría 2019: A.
Escuela: Ingeniería.
Departamento académico: Ingeniería de Producción.
Coordinadora: Édgar Alexander Ossa Henao.
Correo electrónico: eossa@eafit.edu.co

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Mostrando 1 - 5 de 5

Control of Porosity in Freeze Casting
(J O M Institute, 2020-01-01) Gil-Duran S.; Arola D.; Ossa E.A.; Gil-Duran S.; Arola D.; Ossa E.A.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
Many biologic structural materials have porous microstructures with a distribution and orientation of pores that are challenging to achieve using traditional methods of processing. In this investigation, numerical and experimental methods of evaluation were used to understand effects from the primary processing parameters on the temperature gradients during solidification in freeze casting of ceramics. The location and orientation of the temperature gradients were found to be highly dependent on the geometrical and thermal properties of the mold material used in processing. Furthermore, it was found that careful control of these processing variables can be used to design bioinspired porous materials with graded orientations and distributions of pores. © 2020, The Minerals, Metals & Materials Society.
Designed for resistance to puncture: The dynamic response of fish scales
(ELSEVIER SCIENCE BV, 2019-01-01) Ghods S.; Murcia S.; Ossa E.A.; Arola D.; Ghods S.; Murcia S.; Ossa E.A.; Arola D.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
Natural dermal armors are serving as a source of inspiration in the pursuit of “next-generation” structural materials. Although the dynamic strain response of these materials is arguably the most relevant to their performance as armors, limited work has been performed in this area. Here, uniaxial tension and transverse puncture tests were performed on specimens obtained from the scales of Asian carp over strain rates spanning seven decades, from 10-4 to 103 s-1. The importance of anatomical variations was explored by comparing the performance of scales from the head, middle and tail regions. In both loading orientations, the scales exhibited a significant increase in the resistance to failure with loading rate. The rate sensitivity was substantially higher for transverse loading than for in-plane tension, with average strain rate sensitivity exponents for measures of the toughness of 0.35 and 0.08, respectively. Spatial variations in the properties were largest in the puncture responses, and scales from the head region exhibited the greatest resistance to puncture overall. The results suggest that the layered microstructure of fish scales is most effective at resisting puncture, rather than in-plane tension, and its effectiveness increases with rate of loading. X-ray microCT showed that delamination of plies in the internal elasmodine and stretching of the fibrils were key mechanisms of energy dissipation in response to puncture loading. Understanding contributions from the microstructure to this behavior could guide the development of flexible engineered laminates for penetration resistance and other related applications. © 2018 Elsevier Ltd
Interfibril hydrogen bonding improves the strain-rate response of natural armour
(Royal Society Publishing, 2019-01-01) Arola D.; Ghods S.; Son C.; Murcia S.; Ossa E.A.; Arola D.; Ghods S.; Son C.; Murcia S.; Ossa E.A.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
Fish scales are laminated composites that consist of plies of unidirectional collagen fibrils with twisted-plywood stacking arrangement. Owing to their composition, the toughness of scales is dependent on the intermolecular bonding within and between the collagen fibrils. Adjusting the extent of this bonding with an appropriate stimulus has implications for the design of next-generation bioinspired flexible armours. In this investigation, scales were exposed to environments of water or a polar solvent (i.e. ethanol) to influence the extent of intermolecular bonding, and their mechanical behaviour was evaluated in uniaxial tension and transverse puncture. Results showed that the resistance to failure of the scales increased with loading rate in both tension and puncture and that the polar solvent treatment increased both the strength and toughness through interpeptide bonding; the largest increase occurred in the puncture resistance of scales from the tail region (a factor of nearly 7). The increase in strength and damage tolerance with stronger intermolecular bonding is uncommon for structural materials and is a unique characteristic of the low mineral content. Scales from regions of the body with higher mineral content underwent less strengthening, which is most likely the result of interference posed by the mineral crystals to intermolecular bonding. Overall, the results showed that flexible bioinspired composite materials for puncture resistance should enrol constituents and complementary processing that capitalize on interfibril bonds. © 2019 The Author(s) Published by the Royal Society. All rights reserved.
The limiting layer of fish scales: Structure and properties
(ELSEVIER SCI LTD, 2018-02-01) Arola D.; Murcia S.; Stossel M.; Pahuja R.; Linley T.; Devaraj A.; Ramulu M.; Ossa E.A.; Wang J.; Arola D.; Murcia S.; Stossel M.; Pahuja R.; Linley T.; Devaraj A.; Ramulu M.; Ossa E.A.; Wang J.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
Fish scales serve as a flexible natural armor that have received increasing attention across the materials community. Most efforts in this area have focused on the composite structure of the predominately organic elasmodine, and limited work addresses the highly mineralized external portion known as the Limiting Layer (LL). This coating serves as the first barrier to external threats and plays an important role in resisting puncture. In this investigation the structure, composition and mechanical behavior of the LL were explored for three different fish, including the arapaima (Arapaima gigas), the tarpon (Megalops atlanticus) and the carp (Cyprinus carpio). The scales of these three fish have received the most attention within the materials community. Features of the LL were evaluated with respect to anatomical position to distinguish site-specific functional differences. Results show that there are significant differences in the surface morphology of the LL from posterior and anterior regions in the scales, and between the three fish species. The calcium to phosphorus ratio and the mineral to collagen ratios of the LL are not equivalent among the three fish. Results from nanoindentation showed that the LL of tarpon scales is the hardest, followed by the carp and the arapaima and the differences in hardness are related to the apatite structure, possibly induced by the growth rate and environment of each fish.STATEMENT OF SIGNIFICANCE: The natural armor of fish, turtles and other animals, has become a topic of substantial scientific interest. The majority of investigations have focused on the more highly organic layer known as the elasmodine. The present study addresses the highly mineralized external portion known as the Limiting Layer (LL). Specifically, the structure, composition and mechanical behavior of the LL were explored for three different fish, including the arapaima (Arapaima gigas), the tarpon (Megalops atlanticus) and the carp (Cyprinus carpio). Results show that there are significant differences in the surface morphology of the LL from posterior and anterior regions in the scales, and between the three species. In addition, the composition of the LL is also unique among the three fish. Results from nanoindentation showed that the LL of tarpon scales is the hardest, followed by the carp and the arapaima and the differences in hardness are related to the apatite structure, possibly induced by the growth rate and environment of each fish. In addition, a new feature was indentified in the LL, which has not been discussed before. As such, we feel this work is unique and makes a significant contribution to the field. Copyright © 2017 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.
Reduction in Fracture Resistance of the Root with Aging
(Elsevier Inc., 2017-09-01) Yan W.; Montoya C.; Øilo M.; Ossa A.; Paranjpe A.; Zhang H.; Arola D.; Yan W.; Montoya C.; Øilo M.; Ossa A.; Paranjpe A.; Zhang H.; Arola D.; Universidad EAFIT. Departamento de Ingeniería de Producción; Materiales de Ingeniería
Introduction: The incidence of vertical root fracture in endodontically treated teeth increases with patient age. This study evaluated the microstructure, chemical composition, and mechanical properties of radicular dentin as a function of aging. Methods: Single-rooted teeth were obtained from adult donors ranging from age 15 to older than 80 years. Beams were extracted from the middle third of the root and subjected to 4-point flexure to failure to evaluate strength of dentin in terms of donor age. Based on the strength distribution, the fatigue strength of root tissue from young (<= 30 years) and old (>= 55 years) donor teeth was evaluated via cyclic flexure loading. The microstructure and chemical composition of radicular dentin from the 2 groups were evaluated as a function of distance from the root apex using microscopy and Raman spectroscopy, respectively. Results: The strength decreased with age by approximately 25 MPa per decade, which resulted in a significant difference (P <= .0001) between the young (199 +/- 36 MPa) and old (122 +/- 11 MPa) groups. There was also a significant difference (P <= .0001) in fatigue strength between the young and old age groups. Both the mineral-to-collagen ratio and degree of cross-linking increased with age, with the largest changes identified in the apical and middle thirds, respectively. Conclusions: There is a reduction in the damage tolerance of radicular dentin with increasing age. This degradation appears to result from changes in the microstructure, corresponding chemical composition, and increase in collagen cross-linking with age, and is most severe near the root apex.

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Examinando Materiales de Ingeniería por Autor "Arola D."

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