Ciencias Exactas y Ciencias de la Salud
Permanent URI for this collectionhttps://hdl.handle.net/11285/551039
Pertenecen a esta colección Tesis y Trabajos de grado de las Maestrías correspondientes a las Escuelas de Ingeniería y Ciencias así como a Medicina y Ciencias de la Salud.
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- Study of the mechanical behavior and cell viability on 3D-printed Ti6Al4V surfaces: porosity optimization for intervertebral spacer design(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2025-12) Hidalgo Ayala, Gabriela; García López, Erika; Lopez Botello, Omar Eduardo; mtyahinojosa, emipsanchez; Vázquez Lepe, Elisa Virginia; Trujillo de Santiago, Grissel; Escuela de Ingenieria y Ciencias; Campus MonterreyAdditively manufactured porous titanium implants offer a promising strategy to reduce stress shielding and promote bone interaction in spinal fusion procedures. In this work, Ti-6Al-4V lattice structures fabricated by Electron Beam Melting (EBM) were evaluated as candidates for intervertebral spacer applications. Three pore sizes (0.8 , 0.9, and 1.0 mm) were designed and produced using an Additive Arcam SPECTRA L (GE, Gothenburg, Sweden), along with solid EBM and cast Ti-6Al-4V controls. The study combined structural, mechanical, and in vitro biological characterization to determine how pore size influences performance. Dimensional analysis using scanning electron microscopy and ImageJ confirmed good geometric fidelity between CAD models and as-built lattices, with the 0.9 mm configuration showing the smallest deviation in pore diameter and strut thickness. Under uniaxial compression (ASTM E9), increasing pore size reduced both strength and stiffness. The 0.9 mm lattice exhibited a maximum compressive stress of approximately 564 MPa and an apparent modulus of approximately 13.5 GPa, values closer to those of vertebral trabecular bone than to those of solid Ti-6Al-4V. Attempts to perform compression fatigue testing (ASTM E466) revealed limitations of standard displacement-based preload protocols for highly compliant lattices, highlighting the need for adapted fatigue methodologies. A separate rotational fatigue test on a solid EBM specimen confirmed the correct functioning of the fatigue equipment. Biological performance was assessed using C2C12 murine myoblasts cultured on Ti-6Al-4V discs representing each pore size. Fluorescence imaging (Phalloidin/DAPI) showed robust cell adhesion and organized cytoskeletal structures across all lattices, while Live/Dead assays demonstrated high viability (>97%) with no pore size dependent cytotoxicity. Integrating mechanical, structural, and cellular findings, the 0.9 mm lattice emerged as the promising design, offering favorable balance between biomechanical compatibility, structural integrity and early cell response for potential use in intervertebral spacer implants.
- Design of thermoelectric heat exchangers for additive manufacturing(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2024-06-14) Abrego Flores, Oscar Enrique; Rodríguez, Ciro Ángel; emimmayorquin; Cedeño, Luis Daniel; Escuela de Ingeniería y Ciencias; Campus Monterrey; Martínez, José IsraelThis document presents the thesis of the Design of Heat Exchangers with Additive Manufacturing for Thermoelectric Module Systems for the Master of Science with major in Manufacturing Systems at Tecnológico de Monterrey. This study investigates the overall performance and manufacturing process for a heat exchanger equipped with a thermoelectric module (TEM) for cooling systems. A TEM system is a solid-state power converter consisting of an array of thermocouples connected electrically in series and thermally in parallel. Normally, it is used as an arrangement of many TE modules connected electrically in series and thermally in parallel to maximize the results. However, when it is desired to cool other components, a heat exchanger is attached to transmit the energy. Recently, TEM systems have been proposed to substitute conventional heating, ventilation, and air conditioning (HVAC) systems due to their compact designs, lower maintenance and multiples uses modes. However, TEM systems usually have lower efficiency than conventional HVAC systems. This document explores using additive manufacturing to produce novel heat exchangers with a potential application in TEM devices. In this research was manufactured via Laser Powder Bed Fusion (L-PBF) three heat exchangers from which two are made with a novel design based on gyroid lattice structure in order to compare with traditional heat exchangers. The results indicated a 25% improvement in cooling capacity for a heat exchanger with a gyroid structure with at least 1mm of wall thickness. The methodology followed for this research is presented with a theoretical background, analysis, experimentation and simulation of the heat exchanger in order to evaluate its performance with TEM systems for cooling. The expected contribution of this research is to generate new knowledge about the application of heat exchangers with complex structures (achieved by additive manufacturing) in the application of climatization with thermoelectric systems, since a point of view of production until an improvement on thermal efficiency, also propose an experimental setup that can be replicated by other researchers to test the cooling capacity of novel heat exchangers.
- Enhanced mechanical characteristics of Inconel-718 lattice structures produced by laser powder-based fusion with heat treatments(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2022-06-12) Briones Montemayor, María José; Martínez Romero, Oscar; emipsanchez; Elías Zúñiga, Alex; Olvera Trejo, Daniel; Escuela de Ingeniería y Ciencias; Campus Monterrey; Guzmán Nogales, RigobertoThis thesis explores the mechanical properties of four lattice structures—BCC, diamond, IWP, and gyroid—selected for their load-carrying and energy absorption capabilities. Compression tests reveal that the BCC and diamond structures exhibit larger plastic zones, while the IWP demonstrates superior energy absorption per volume, attributed to its smoother surface geometry resembling the BCC structure. The gyroid structure displays the highest yield strength. The selected heat treatments, HT1, HT2, and HT3, yield similar results, though variations in microstructure and grain size significantly affect mechanical properties. HT2, with its δ-phase boundaries, exhibits promising outcomes. The combination of HT2 and gyroid structure enhances yield strength by 94%, making it ideal for high-strength applications. Similarly, the pairing of IWP and HT2 increases energy absorption per volume by 48%, suitable for energy dissipation applications. XRD analysis revealed significant changes in the principal crystalline planes (111, 200, and 220) across different heat treatments. HT2 exhibited the most pronounced phase transformations, with sharp XRD peaks and reduced microstrain, correlating with the largest grain sizes and the highest mechanical performance. HT1 showed initial microstructural adjustments with smaller grain growth and moderate mechanical properties, while HT3 resulted in a balanced microstructure with stable and moderate mechanical performance. Integrating lattice structures with heat treatments enhances material properties, with HT2 emerging as a promising treatment for advanced material applications. Recommendations for future research include exploring microstructural evolution, long-term material performance, fatigue behavior, and cooling rate effects.
- A study of variation in the cross-sectional areas of thermoplastic filaments on lattice structures manufactured by fused filament fabrication(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2021-12-02) Moreno Núñez, Benjamín Alberto; ; Treviño Quintanilla, Cecilia Daniela; puemcuervo/tolmquevedo; Cuan Urquizo, Enrique; Espinoza García, Juan Carlos; Uribe Lam, Esmeralda; School of Engineering and Sciences; Campus MonterreyThis research was focused on developing a method to control the width of extruded filaments, to have a controlled structure of the infills of 3D printed products manufactured by Fused Filament Fabrication (FFF). Different parameters and their effect on the width of extruded filaments in FFF were studied. The materials used were three thermoplastic filaments: polylactic acid (PLA), acrylonitrile butadiene styrene (ABS), and polycarbonate (PC). The extruded filament widths were measured using optical characterization and analyzed using statistical analysis. Two different approaches were followed. First, an experimental one, in which the effect of the extrusion temperature, the feed rate, the layer height, the fan power, and the bed temperature on the width was studied. A factorial design of experiments was performed using the previously mentioned parameters, in which different combinations were made to obtain the experimental data and perform a regression analysis that explains and predicts the width of the filaments after extrusion. A second approach was done to obtain an empirical model that predicts the die-swell of the filament when it is extruded. To obtain this model, two different mathematical models were selected from the literature. The first model explains the pressure inside a nozzle, considering the rheological properties and parameters of the FFF process. The second model predicts filament die-swell after extrusion, considering extrusion pressure, extrusion temperature, printing speed, and nozzle diameter. In the end, an empirical model was done by adapting the pressure model to the die-swell model and it was possible to obtain the values that could give a controlled thickening considering the extrusion temperature and adjusting the printing speed.