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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- Influence of process parameters on surface topography of nitinol manufactured by fiber laser cutting for medical applications(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2021-12-09) Cadena Calvillo, Mariana; VAZQUEZ LEPE, ELISA VIRGINIA; 268852; Vázquez Lepe, Elisa Virginia; puelquio/mscuervo; Rodríguez González, Ciro Ángel; López Botello, Omar Eduardo; School of Engineering and Sciences; Campus Monterrey; García López, ErikaThe need and tendency to develop medical devices on the micron scale has created an opportunity to micro cutting processes that have the capability of manufacturing quality medical devices. Thereby, the necessity of materials that have unique features to improve the deliverability and the performance of these devices have made nitinol one of the most selected materials for this industry. Nevertheless, the study of the micro processing of nitinol tube for the application on medical devices, through fiber laser cutting and its response to surface quality has not been thoroughly researched. Hence, in this research the response of fiber laser cutting parameters, such as spot overlapping and pulse energy, on Ni-Ti alloy (nitinol) was statistically analyzed through surface quality through average surface roughness, and heat-affected zone. Results showed that spot overlap had most impact on surface quality, since surface roughness decreased increasing spot overlap, but further increase resulted on increased surface. Minimum surface roughness of 1.482 µm, with 83.72% of spot overlap and 72.16 of pulse energy. Presence of HAZ, and dross found on highest values of spot overlap and pulse energy. In conclusion, fiber laser cutting has the capability to produce high surface quality nitinol self-expanding stents.
- Hybrid additive manufacturing for tooling applications(Instituto Tecnológico y de Estudios Superiores de Monterrey, 2020-12-08) Galván Camarena, Omar Karim; RODRIGUEZ GONZALEZ, CIRO ANGEL; 20794; Rodríguez González, Ciro Angel; puelquio, emipsanchez; Vázquez Lepe, Elisa Virginia; López Botello, Omar Eduardo; Escuela de Ingeniería y Ciencias; Campus MonterreyThe requirements for tooling manufacturing are dimensional accuracy, surface performance, hardness, wear resistance, fatigue strength, repairability and cost. In this research, a methodology for hybrid additive manufacturing, Direct Energy Deposition (DED) and milling process was tested on geometries and materials relevant to the tooling industry. The first stage consisted of the powder feeder characterization. Next, a full design of experiments evaluating laser power, feed, and mass flow with three levels each and their impact on height and width. The third stage was to evaluate the internal structure of single lines with three sets of parameters, evaluating height, width, melting pool height and porosity. Afterwards, five different layer thicknesses were tested on thin walls of six layers each. The results show the effect of layer thickness on the height of the wall, melting pool height and wall’s porosity. Finally, two different scanning strategies were tested to evaluate cubic geometries. The scanning strategies were zigzag 90° and zigzag 360°. Cubic geometries created on DED were machined to create truncated pyramids with a 3° angle by milling. Three different feed per tooth were tested each 2.5 mm of the truncated to evaluate the surface roughness. Results showed a parabolic behavior and the best value for average surface roughness near 0.4 micrometers. After the analysis, the hardness of the samples was characterized by a hardness test. The results showed an average hardness between 30 and 50 HRC which is between the operational hardness values for the tooling industry.