Utilización de la técnica de microscopía de imágenes de orientación para relacionar la microtextura de aceros laminados en caliente con la anisotropía

Tesis (Doctor en Ingeniería de Materiales) UANL, 2000.UANLhttp://www.uanl.mx

Feasibility of manufacturing combustion chambers for aeronautical use in Mexico

The aeronauticalsectorisstrategically importantforthe economic development ofMexico and has grown steadily overthe last 10 years. Furthermore, it generates high added value for its products. In Mexico, the aircraft manufacturing sector mainly focuses on the fabrication of heat exchangers, seals, fuel ducts, and engine support rings. Currently, this sector is not involved in the manufacture of engine hot section components such as combustion chambers and turbine blades. Estimation of the associated costs enables assessment of the feasibility of fabricating such components. This study investigates the feasibility of establishing production lines for aeronautical combustion chamber fabrication in factories dedicated to the manufacture of aeronautical gas turbine engines

Modelado de las fuerzas de corte en el torneado de alta velocidad utilizando redes neuronales artificiales

Cutting forces are very important variables in machining performance because they affect surface roughness, cutting tool life, and energy consumption. Reducing electrical energy consumption in manufacturing processes not only provides economic benefits to manufacturers but also improves their environmental performance. Many factors, such as cutting tool material, cutting speed, and machining time, have an impact on cutting forces and energy consumption. Recently, many studies have investigated the energy consumption of machine tools; however, only a few have examined high-speed turning of plain carbon steel. This paper seeks to analyze the effects of cutting tool materials and cutting speed on cutting forces and Specific Energy Consumption (SEC) during dry high-speed turning of AISI 1045 steel. For this purpose, cutting forces were experimentally measured and compared with estimates of predictive models developed using polynomial regression and artificial neural networks. The resulting models were evaluated based on two performance metrics: coefficient of determination and root mean square error. According to the results, the polynomial models did not reach 70 % in the representation of the variability of the data. The cutting speed and machining time associated with the highest and lowest SEC of CT5015-P10 and GC4225-P25 inserts were calculated. The lowest SEC values of these cutting tools were obtained at a medium cutting speed. Also, the SEC of the GC4225 insert was found to be higher than that of the CT5015 tool.Las fuerzas de corte son variables muy importantes para el rendimiento del mecanizado, ya que afectan la rugosidad de la superficie, la vida útil de la herramienta de corte y el consumo de energía. La reducción del consumo de energía eléctrica de los procesos de fabricación no solo beneficia económicamente a los fabricantes, sino que también mejora su comportamiento medioambiental. Muchos factores, como el material de la herramienta de corte, la velocidad de corte y el tiempo de mecanizado, afectan la fuerza de corte y el consumo de energía de la máquina. En la actualidad, muchas investigaciones se han realizado sobre el consumo energético de las máquinas herramienta. Sin embargo, la investigación sobre torneado de acero al carbono a alta velocidad es escasa. En este trabajo se estudiaron los efectos de los materiales de las herramientas de corte y su velocidad sobre las fuerzas de corte y el consumo específico de energía en el torneado en seco de alta velocidad de acero AISI 1045. Las fuerzas de corte se determinaron experimentalmente y se compararon con las estimaciones de los modelos predictivos desarrollados mediante regresión polinomial y redes neuronales artificiales. Los modelos obtenidos fueron evaluados según métricas de desempeño como el coeficiente de determinación y la raíz del error cuadrático medio, donde los modelos polinomiales no superaron el 70% en la representación de la variabilidad de los datos. Se determinó la velocidad de corte y el tiempo de mecanizado relacionados con el mayor y menor consumo de energía de las plaquitas CT5015-P10 y GC4225-P25. Los valores más bajos de consumo de energía de estas herramientas se alcanzaron para la velocidad de corte intermedia. Además, la plaquita GC4225 presentó un mayor consumo que la herramienta CT5015

Feasibility of manufacturing combustion chambers for aeronautical use in Mexico-NC-ND 4.0

Abstract The aeronautical sector is strategically important for the economic development of Mexico and has grown steadily over the last 10 years. Furthermore, it generates high added value for its products. In Mexico, the aircraft manufacturing sector mainly focuses on the fabrication of heat exchangers, seals, fuel ducts, and engine support rings. Currently, this sector is not involved in the manufacture of engine hot section components such as combustion chambers and turbine blades. Estimation of the associated costs enables assessment of the feasibility of fabricating such components. This study investigates the feasibility of establishing production lines for aeronautical combustion chamber fabrication in factories dedicated to the manufacture of aeronautical gas turbine engines. All Rights Reserve

Cambio del tamaño de grano de una aleación de inconel 617 al ser maquinada

Una aleación base níquel, inconel 617 se maquinó a diferentes condiciones para evaluar su comportamiento superfi cial y analizar los cambios en el tamaño de grano. Para esta descripción se tomaron en cuenta diferentes parámetros, manteniendo constantes el herramental y las velocidades de corte, variando los avances. Los resultados muestran que el tamaño de grano es sensible al avance

High-Temperature Oxidation of Superalloy C-263 of Rings for Aircraft Engines

The present investigation was conducted to study the oxidation kinetics of nickel-based superalloy 263, used in the manufacture of rings for aircraft engines. For carrying out this study, we first conducted microstructural characterization of the pieces using the techniques of optical microscopy, scanning electronic microscopy, and X-ray diffraction. Subsequently, using the thermogravimetric analysis, the kinetic oxidation of the metal was performed in a temperature range between 700 and 1000°C, using atmospheres of O2. The results of the micrographs show the formation of a protective oxide film on the surface of the material in different oxidizing agents. Finally, it was found that the kinetics of high-temperature oxidation of the superalloy C-263 obeys the parabolic rate law

Estudio del desgaste del flanco de carburos recubiertos y cermet durante el torneado de alta velocidad en seco del acero AISI 1045

RESUMEN El objetivo de este trabajo es el estudio experimental de la evolución del desgaste del flanco respecto al tiempo de dos insertos de carburo recubiertos y un cermet durante el torneado de acabado en seco del acero AISI 1045 con velocidades de corte de 400, 500 y 600 m/min. Los resultados fueron comparados utilizando el análisis de varianza y el análisis de regresión lineal para describir la relación entre el desgaste del flanco y el tiempo de maquinado, obteniéndose la ecuación del modelo ajustado. La investigación demostró un efecto significativo de la velocidad de corte y del tiempo de maquinado en el desgaste del flanco en el maquinado de alta velocidad. El mejor desempeño se obtuvo para el carburo recubierto con tres capas, mientras que el carburo con dos capas sufrió el mayor desgaste a elevadas velocidades de corte. ABSTRAC This work deals with the experimental study of the flank wear evolution of two coating carbide inserts and a cermet insert during the dry finishing turning of AISI 1045 steel with 400, 500 and 600 m/min cutting speeds. The results were analyzed using the variance analysis and lineal regression analysis in order to describe the relationship between the flank wear and machining time, obtaining the adjusted model equation. The investigation demonstrated a significant effect of cutting speed and machining time on the flank wear at high speed machining. The three coating layers insert showed the best performance while the two layers insert had the worst behaviour of the cutting tool wear at high cutting speeds

Análisis del rendimiento del torneado utilizando coeficiente de vida útil en relación al volumen de metal cortado

RESUMEN Los aceros inoxidables austeníticos son materiales difíciles de mecanizar, debido a su alta resistencia, alta ductilidad y baja conductividad térmica. El objetivo de este trabajo es proponer un nuevo criterio para evaluar el rendimiento del torneado de alta velocidad mediante la relación del desgaste del flanco con el volumen de metal cortado. La influencia de los parámetros de corte sobre el coeficiente de vida útil en relación al volumen de metal cortado fue analizada utilizando un análisis de varianza y de regresión múltiple. La investigación mostró un mejor rendimiento del inserto GC2015 en ambas velocidades de corte. El análisis de varianza factorial demostró un efecto significativo del tiempo de mecanizado en el coeficiente de vida útil en relación al volumen de metal cortado. Palabras clave: Torneado de alta velocidad, desgaste del flanco, acero inoxidable AISI 316L, análisis de varianza y regresión, volumen de metal removido. ABSTRACT The austenitic stainless steels are difficult material to machine due to their high strength, high ductility and low thermal conductivity. The aim of this paper is to propose a new criterion for assessing the performance of high speed turning by relating the flank wear with the volume of material removed. The influence of cutting parameters on the coefficient of life in relation to the volume of material removed was analyzed using analysis of variance and multiple regression. The investigation showed a better performance with the GC 2015 insert in both cutting speed. The analysis of factorial variance showed a significant effect of the machinization time in the coefficient of life in relation to the volume of material removed. Keywords: High speed turning, stainless steel AISI 316L, flank wear, variance and regressions analysis, volume of the cut metal

Microstructural Development in a TRIP-780 Steel Joined by Friction Stir Welding (FSW): Quantitative Evaluations and Comparisons with EBSD Predictions

The present work describes the effect of FSW on the result microstructure in the stir zone (SZ), thermo-mechanically affected zone (TMAZ), heat affected zone (HAZ) and base metal (BM) of a TRIP-780 steel. X-ray diffraction (XRD), optical microscopy (OM) and EBSD were used for determinations retained austenite (RA) in the SZ, It was found that the amount of RA developed in SZ was relatively large, (approximately 11% to 15%). In addition, recrystallization and the formation of a grain texture were resolved using EBSD. During FSW, the SZ experienced severe plastic deformation which lead to an increase in the temperature and consequently grain recrystallization. Moreover, it was found that the recrystallized grain structure and relatively high martensite levels developed in the SZ lead to a significant drop in the mechanical properties of the steel. In addition, microhardness profiles of the welded regions indicated that the hardness in both the SZ and TMAZ were relatively elevated confirming the development of martensite in these regions. In particular, to evaluate the mechanical strength of the weld, lap shear tensile test was conducted; exhibited the fracture zone in the SZ with shear fracture with uniformly distributed elongation shear dimples