Ball burnishing is a finishing technique involving plastic deformation on the workpiece surface. In this paper, the influence of the ball burnishing operation on the average roughness, tensile properties, anisotropy and work hardening of a TRIP steel was analyzed. An experimental study of the effect of the ball burnishing process on uniaxial tensile specimens was conducted using the Response Surface Methodology (RSM) based on a 3 2 Factorial Design (FD). The effects of burnishing force (B F ) and the number of tool passes (N P ) on the average roughness (R a ), the yield stress (σ Y ) and the percentage of elongation to fracture (% El) were evaluated. The quadratic regression models were obtained to predict R a and σ Y with determination coefficients (R 2 ) of 0.85 and 0.99, respectively. The results indicated that the ball burnishing process produces a maximum reduction of R a of 81.7% (from 1.250 to 0.229 μm). Also, it was observed that the ductility of the material increased in a 25% and the yield stress and work hardening can be substantially modified. Finally, it was found that by using the ball burnishing process, the planar anisotropy of the sheet can be reduced.

Common assumption in analysis of a flexible one-link robot is to take account of a DC motor as actuator. This work presents the design and stability analysis of a tracking controller of a flexible-robot including the dynamics of a 3-phase induction motor, despite of its high nonlinear dynamics, to drive the joint of the one-link arm. In this manner, the dynamic model of a joint-flexible-robot is combined with the induction motor model to build the motion equations. A control law is proposed for the flexible one-arm robot to track a desired trajectory, thus, this control input is used like the reference torque for the induction motor control. A stability analysis by Lyapunov criterion is detailed to demonstrate the tracking errors are globally exponentially stable. Simulations show the effectiveness of the proposed approach even when the one-link arm is subjected to uncertainty in parameters and external disturbances.

In sheet metal forming, residual stresses are related to springback and material failure after the deformation process or during service due to load history. Thus, being able to either calculate or measure such stresses is of great importance. This paper aims to evaluate the use of the Electronic Speckle Pattern Interferometry (ESPI) technique to measure residual stresses on TRIP steel. Residual stresses are measured after springback on specimens used in three-point bending tests; where three bending angles are considered. Experiments are compared with Finite Element calculations in terms of punch force, springback angle and residual stresses. Work-hardening and anisotropy parameters, used in simulations, are experimentally determined by the uniaxial tensile test. Results indicate that advanced hardening models are necessary to increase the accuracy of springback predictions. Nevertheless, residual stress calculations show a good correlation with experimental values. Also, it was proved that ESPI is a powerful technique to measure the residual stress on complex surfaces, as the ones typically encountered in sheet forming processes. Future work includes residual stress predictions for different forming processes.

The surface finish of industrial components has an important role in their performance and lifetime. Therefore, it is crucial to find the cutting parameters that provide the best surface finish. In this work, an experimental study of the effect of cutting parameters on ultra-high molecular weight polyethylene (UHMWPE) by a turning process was carried out. Today, the UHMWPE polymer continues to find applications mainly in the automotive industry and biomechanics because it is resistant to impact and corrosive materials to use. A face-centered Central Composite Design (CCD) and Response Surface Methodology (RSM) were applied to evaluate the influence of the cutting speed (Vc), feed rate (f) and depth of cut (ap) of the turning operation on the Average Surface Roughness (Ra) and Material Removal Rate (MRR). Results allowed obtaining an adjusted multivariable regression model that describes the behavior of the Ra that depends on the cutting parameters in the turning process. The predictive model of Ra showed that it fits well with a correlation coefficient (R2) around 0.9683 to the experimental data for Ra. The ANOVA results for Ra showed that the feed is the most significant factor with a contribution of 42.3 % for the term f 2, while the speed and depth of cut do not affect Ra with contributions of 0.19% and 0.18%, respectively. A reduction of feed from 0.30 to 0.18 mm·rev−1 produces a decrease in surface roughness from 6.68 to 3.81 μm. However, if the feed continued to reduce an increase in surface roughness, a feed of 0.05 mm·rev−1 induces a surface roughness of 14.93 μm. Feeds less than 0.18 mm·rev−1 cause a heat generation during turning that increases the temperature in the process zone, producing surface roughness damage of the UHMWPE polymer. Also, the results for MRR demonstrated that all of the cutting parameters are significant with contributions of 31.4%, 27.4% and 15.4% to feed, speed, and depth of cut, respectively. The desirability function allowed optimizing the cutting parameters (Vc = 250 m·min−1, ap = 1.5 mm y f = 0.27 mm·rev−1) to obtain a minimum surface roughness (Ra = 4.3 μm) with a maximum material removal rate (MMR = 97.1 cm3·min−1). Finally, the predictive model of Ra can be used in the industry to obtain predictions on the experimental range analyzed, reducing the surface roughness and the manufacturing time of UHMWPE cylindrical components.

The objective of this work is to determine the influence of Minimum Quantity Lubrication (MQL) parameters on flank wear during face milling. Furthermore, the values of each factor in which the MQL resulted to be effective were determined. A designed experiment with two level, three factor and two replicas was used to test tool wear on P45 grade inserts at relatively high cutting speed (~900 m/min) on steel AISI 1045. A commercial MQL system was used with vegetable base lubricant non soluble in water. Results show that amount of lubricant and vertical angle are key factors that affects the effectiveness of the process. A response surface equation was obtained in order to determine the zones in which the factors resulted in the lowest tool wear. A flank wear decrease of 7 times, respect to the maximum observed, was found by using low level of air flow, low level of vertical angle and high level of lubricant.