Alberto Saldaña Robles

EL PROCESO DE BRUÑIDO CON BOLA: ESTADO DEL ARTE DE UNA TECNOLOGÍA EN DESARROLLO

El brunido de bola es un proceso secundario de mejoramiento de las propiedades fisico-mecanicas y el acabado superficial de piezas manufacturadas. A pesar de ser conocido hace mas de 30 anos, recientemente se ha visto potencializado su uso industrial en diversas aplicaciones como la fabricacion de moldes para inyeccion de plastico, herramentales para el conformado de metales, asi como, numerosos componentes en la industria automotriz, ferrocarrilera, aeronautica y aeroespacial; por lo que su investigacion es fundamental. En las ultimas decadas diversas investigaciones se han enfocado en el estudio teorico, numerico y experimental del proceso de brunido de bola; con la finalidad de estudiar, predecir y analizar la influencia de parametros especificos que permitan mejorar la comprension del proceso asi como la optimizacion de los parametros involucrados en el. En este articulo, se presenta un analisis de diversos articulos cientificos, que son de gran relevancia para el proceso de brunido de bola. El estudio permite acelerar la comprension del proceso, presentando un estudio actualizado del estado del arte e identificando las diversas areas de oportunidad para mejorarlo.

ANALISIS TEÓRICO-NUMÉRICO-EXPERIMENTAL DE UN PROCESO DE HIDROCONFORMADO USANDO DIÁMETRO EQUIVALENTE

The main goal of this work is to propose the application of the concept of equivalent diameter in the calculation of the hydraulic pressure required to conduct an hydroforming process in non-circulars pieces. Although this approach was carried out initially for the conventional stamping process, this paper demonstrates that it can also be applied in hydroforming. In a first phase experimental tests were carried out to form a part using this methodology, measuring the reduction in resulting thickness. It was found that difference between the calculated pressure and the experimental required pressure was 2.6%. To perform a numerical-experimental comparison, the simulation of the process was carried out using several material models by explicit finite element method in a commercial software. It was observed that using the material model HILL’90 deviation between experimental and numerical results for the thickness reduction was lower than 5.5%.

MODELADO TRIDIMENSIONAL DE RUGOSIDAD SUPERFICIAL PARA EL PROCESO DE BRUÑIDO

Ball burnishing is a plastic deformation process that improves the surface quality of mechanical parts decreasing roughness. The surface roughness is an important parameter of study; it is known that affects friction, lubrication and wear. In this work, a general methodology for finite element and a programming routine based on Parametric Design Language was developed and validated. This methodology is useful to generate parametric models of three-dimensional rough surfaces in a commercial software of finite element. The routine produces a random surface roughness using the mean (x ?) and standard deviation (s) of a normal distribution of real surface roughness. The routine was used to generate roughness models of rectangular and cylindrical specimens. The nodal density for generating roughness and repeatability for a given surface finish were evaluated to optimize the modeled surface roughness. The numerical results show a good correlation to the experimental results. In a future, the routine can be used to generate models through the finite element method to simulate any machining process with random roughness and this enable to study the processes, allowing reducing the high costs of experimental tests.