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Full-Text Articles in Engineering
Sorting Of Single Walled Carbon Nanotubes En Route To Exploring Nano-Scale Molecular Cloaking In Hydorocarbon Based Structures, Bohao Li
All ETDs from UAB
Carbon nanotubes have been widely used as a reinforcement in polymer materials in various ways due to their high mechanical strength, excellent electrical conductivity, and great thermal conductivity. In this paper, we will investigate the effects of length and chirality of carbon nanotubes on the properties of nanocomposite as just mentioned. Therefore we demonstrate a carbon nanotubes length separation method, and further validate the length of individual fractional carbon nanotubes after separation by UV-Vis spectroscopy and atomic force microscopy (AFM). Chirality-separated, length-separated SWNT fraction via the ultracentrifugation technique is also demonstrated. Due to the differences in the scaling of buoyancy …
Microstructural Analysis Of Aluminum High Pressure Die Castings, Maria Diana David
Microstructural Analysis Of Aluminum High Pressure Die Castings, Maria Diana David
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Microstructural analysis of aluminum high pressure die castings (HPDC) is challenging and time consuming. Automating the stereology method is an efficient way in obtaining quantitative data; however, validating the accuracy of this technique can also pose some challenges. In this research, a semi-automated algorithm to quantify microstructural features in aluminum HPDC was developed. Analysis was done near the casting surface where it exhibited fine microstructure. Optical and Secondary electron (SE) and backscatter electron (BSE) SEM images were taken to characterize the features in the casting. Image processing steps applied on SEM and optical micrographs included median and range filters, dilation, …
Fiber Metal Laminate With Thickness Reinforcement, Pritesh S. Yeole
Fiber Metal Laminate With Thickness Reinforcement, Pritesh S. Yeole
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In this study, a new hybrid fiber metal laminate (FML) material is developed in which fiber composites (both thermoset and thermoplastic matrix composites) and metal are bonded together mechanically using the hooks integrated on the metal. The hooks function as through thickness reinforcement and are used to enhance the bonding strength between the fiber composites and the metal. Process optimization is performed for the VARTM process used in manufacturing the thermoset composite FML in order to gain full benefit of the through thickness reinforcement. Extra pressure in addition to the vacuum is applied to push fiber tows inside the hooks …
Computational Modelling And Surface Charachterization Of Interface In Polymer Composites By Atomic Force Microscopy, Daljeet Kumar Singh
Computational Modelling And Surface Charachterization Of Interface In Polymer Composites By Atomic Force Microscopy, Daljeet Kumar Singh
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Polymer composites are used in numerous industries due to their high specific strength and high specific stiffness. Such composites have markedly different properties than both the reinforcement and the matrix. Of the several factors which govern the final property of the composite, the interface is the single most factor that influences the stress transfer mechanism from the fiber to the matrix. The interface bond strength is also influenced by the surface treatments applied to the fiber during spinning and weaving. The present study is an effort to characterize and model the fiber-matrix interface in polymer matrix composites. Finite element models …
Characterization Of Directionally Solidified Gray Iron, Elis Annexy Rivera-Martinez
Characterization Of Directionally Solidified Gray Iron, Elis Annexy Rivera-Martinez
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Even with decades of study, the complex development of solidification microstructures in cast iron is incompletely understood. Because Fe-C eutectic can produce different morphologies, and even different phases, depending on growth velocities and composition, understanding the conditions under which each forms are important. Directional solidification was used to observe the behavior of gray cast iron under carefully controlled solidification conditions. Specifically, alloys with industrially relevant amounts of silicon and manganese were studied, using a Bridgman furnace to investigate the effects of alloying additions and solidification velocity on graphite spacing and growth temperature of gray iron. An experimental technique for measuring …