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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- Micro machinability of net shapes of Selective Laser Melting of Ti-6Al-4V for minimum material removal using ball end mill(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2018-05-15) Celis Renata, Pavel; Vázquez Lepe, Elisa Virginia; García López, Erika; Rodríguez González, Ciro Ángel; Sandoval Robles, Jesús A.Miniaturization of medical devices is playing an important role in the manufacture industry. New drug delivery systems are being studied and developed, therefore materials to produce these devices must be investigated extensively. The objective of this work is to experimentally investigate and compare the machinability of Ti-6Al-4V titanium alloy produced via Selective laser melting (SLM) against the conventional machining method. 18 patches of 09 needles each were fabricated and machined with different cutting feeds (120,150 and 180mm/min) with aid of a minimum quantity lubrication (MQL) system. Machinability was examined in terms of cutting forces, tool wear, surface roughness and geometrical dimensions. Each cutting feed was tested by fabricating 3 patches from solid blocks of titanium with square tools of .8mm. Finish pass was performed with a .2mm micro ball end mill with a constant spiral toolpath. Comparison was performed by fabricating four patches with SLM with an excess material of 150μm and machined with the same previous parameters. 3D images obtained by optical microscope reveal that the main force applied in the finishing of needles is the Z axis and cutting forces were higher when machining SLM patches. Tool calibration is the main factor to obtain high precision in geometrical dimensions due to the variation in length because of thermal expansion. Surface roughness for all tests were below 1μm with best results when cutting feed is set at 120mm/min, reduction in edge radius for ball end mills affected negatively the surface roughness. An economic comparison was performed and showed that the SLM combined with SM process has clear advantage over subtractive manufacture alone.
- Design of a Bioabsorbable stent as preventive treatment of complication in bariatric surgery RYGBP(2017-12-05) Jara Mendiola, Juan Manuel; Vázquez Lepe, Elisa Virginia; García López, Erika; Rodríguez González, Ciro ÁngelA new approach to the treatment of complications of RYGBP is covered by the implementation of design methodologies as quality function deployment and theory of inventive problem solving, (QFD and TRIZ) to propose a Design of a bioabsrobable stent as a preventive treatment. In despite on the variability of documented results of degradation rates of bio polymers and bio metals, a new lab protocol is proposed to homogenize both families of materials degradation rates into comparable results. The usage of PLA and AZ31 into a new protocol proposal of degradation tests were carried on. The design resultant by the design methodologies were tested by finite element analysis to compare compression resistance, flexibility and compressibility. Three design proposals are shown with acceptable performance and an expected functional life time.