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Additive manufactured parts often require post-processing to obtain the desired surface finish. In this sense, this work investigates the ball burnishing process’s applicability as a finishing method for fused filament fabricated (FFF) parts. Ball burnishing is a mechanical finishing procedure based on the plastic deformation of the treated surface that could provide significant advantages, as it is non-abrasive and does not chemically interact with the model material. Following Taguchi’s design methodology, optimal values of four burnishing parameters have been identified, and significant improvements in surface quality have been quantitatively and qualitatively proven. Mechanical performance under tensile and flexural loading, impact testing, and bending fatigue of ball-burnished samples has been compared to pristine values. Besides the enhanced surface quality of the samples, a notable finding of the study is a minimum twofold increase in the fatigue life of ball-burnished samples, as well as a higher impact energy absorption. Accordingly, this research provides experimental evidence to set ball burnishing as a novel post-processing technique for FFF parts.
Ariadna Chueca de Bruijn; Giovanni Gómez-Gras; Marco A. Pérez. On the effect upon the surface finish and mechanical performance of ball burnishing process on fused filament fabricated parts. Additive Manufacturing 2021, 46, 102133 .
AMA StyleAriadna Chueca de Bruijn, Giovanni Gómez-Gras, Marco A. Pérez. On the effect upon the surface finish and mechanical performance of ball burnishing process on fused filament fabricated parts. Additive Manufacturing. 2021; 46 ():102133.
Chicago/Turabian StyleAriadna Chueca de Bruijn; Giovanni Gómez-Gras; Marco A. Pérez. 2021. "On the effect upon the surface finish and mechanical performance of ball burnishing process on fused filament fabricated parts." Additive Manufacturing 46, no. : 102133.
The superficial effect of hardening caused after vibration-assisted ball burnishing and its consequences in the tensile behavior of a carbon steel material are studied in this paper. As ball burnishing affects the material to hundredths of micrometers in depth through plastic deformation, the overall macro effect of this modification was studied. Different levels of preload and vibration amplitude were studied to address the described issue. The study was done in two phases. First of all, the depth to which ball burnishing affects the material was studied by performing Vickers indentation tests with different loads. It was proven that the effects of ball burnishing are best represented when a 0.05 kg load is used, as higher loads include more volume of core material in the measurement, hence hiding the effect of ball burnishing. In a second phase, the ball burnished specimens were subjected to tensile tests. It was proven that an increase of burnishing preload diminishes the ductile behavior of the material and increases its strength representative values, although the proportion of affected material in the cross-section of the specimen is reduced with regard to the whole surface. Additionally, as the preload increases, the effects of assistance through vibrations is reduced, and the effect of the static preload acquires more relevance in modifying the macroscopic mechanical properties of the steel alloy. Experiments using different amplitudes and new forces are encouraged to obtain more information about how the material can be modified optimally through vibration-assisted ball burnishing.
Jordi Llumà; Giovanni Gómez-Gras; Ramón Jerez-Mesa; Jaume Rue-Mascarell; J. Antonio Travieso-Rodriguez. Mechanical Strengthening in S235JR Steel Sheets through Vibration-Assisted Ball Burnishing. Metals 2020, 10, 1010 .
AMA StyleJordi Llumà, Giovanni Gómez-Gras, Ramón Jerez-Mesa, Jaume Rue-Mascarell, J. Antonio Travieso-Rodriguez. Mechanical Strengthening in S235JR Steel Sheets through Vibration-Assisted Ball Burnishing. Metals. 2020; 10 (8):1010.
Chicago/Turabian StyleJordi Llumà; Giovanni Gómez-Gras; Ramón Jerez-Mesa; Jaume Rue-Mascarell; J. Antonio Travieso-Rodriguez. 2020. "Mechanical Strengthening in S235JR Steel Sheets through Vibration-Assisted Ball Burnishing." Metals 10, no. 8: 1010.
In comparison with conventional manufacturing technologies, Fused Filament Fabrication (FFF) offers countless benefits. It broadens the horizons of the design of structural components with high geometrical complexity, and lighter elements can be obtained by optimizing the infill of the part. The infill density stands as a manufacturing parameter that plays a significant part in weight reduction purposes. This fact provides FFF with an outstanding competitive advantage as compared to the rest of additive manufacturing technologies. This work aims to investigate the role of infill parameters on the mechanical performance and weight reduction of ULTEMTM 9085 samples processed by FFF, under tensile, flexural, and shear loading conditions in six different orientations with several solid and sparse configurations. Regarding the effect of the part orientation and the infill settings, the experimental results permit to draw conclusions on stiffness, resilience, maximum stress, and type of failure of the printed parts. Three-dimensional compliance matrices for each infill configuration are provided. The analysis of the results correlates the infill configuration with the mechanical performance considering the intra-layer and inter-layer unions. Finally, this research provides experimental evidence to contribute to the definition of novel design-for-manufacturing strategies for obtaining functional structural elements by FFF.
Albert Forés-Garriga; Marco A. Pérez; Giovanni Gómez-Gras; Guillermo Reyes Pozo. Role of infill parameters on the mechanical performance and weight reduction of PEI Ultem processed by FFF. Materials & Design 2020, 193, 108810 .
AMA StyleAlbert Forés-Garriga, Marco A. Pérez, Giovanni Gómez-Gras, Guillermo Reyes Pozo. Role of infill parameters on the mechanical performance and weight reduction of PEI Ultem processed by FFF. Materials & Design. 2020; 193 ():108810.
Chicago/Turabian StyleAlbert Forés-Garriga; Marco A. Pérez; Giovanni Gómez-Gras; Guillermo Reyes Pozo. 2020. "Role of infill parameters on the mechanical performance and weight reduction of PEI Ultem processed by FFF." Materials & Design 193, no. : 108810.
The Fused-Deposition Modelling (FDM) technique has transformed the manufacturing discipline by simplifying operational processes and costs associated with conventional technologies, with polymeric materials being indispensable for the development of this technology. A lack of quantification of viscoelastic/plastic behavior has been noted when addressing FDM parts with Polyetherimide (PEI), which is currently being investigated as a potential material to produce functional end-products for the aerospace and health industry. Primary and secondary creep along with stress relaxation tests have been conducted on FDM PEI specimens by applying stresses from 10 to 40 MPa for 100 to 1000 min. Specimens were 3D printed by varying the part build orientation, namely XY, YZ, and XZ. Creep results were fitted to the Generalized Time Hardening equation (GTH), and then this model was used to predict stress relaxation behavior. FDM PEI parts presented an isotropic creep and stress relaxation performance. The GTH model was proven to have a significant capacity to fit viscoelastic/plastic performances for each single build orientation (r > 0.907, p < 0.001), as well as a tight prediction of the stress relaxation behavior (r > 0.998, p < 0.001). Averaged-orientation coefficients for GTH were also closely correlated with experimental creep data (r > 0.958, p < 0.001) and relaxation results data (r > 0.999, p < 0.001). FDM PEI parts showed an isotropic time-dependent behavior, which contrasts with previous publications arguing the significant effect of part build orientation on the mechanical properties of FDM parts. These findings are strengthened by the high correlation obtained between the experimental data and the averaged-coefficient GTH model, which has been proven to be a reliable tool to predict time-dependent performance in FDM parts.
A. G. Salazar-Martín; A. A. García-Granada; G. Reyes; G. Gomez-Gras; J. M. Puigoriol-Forcada. Time-Dependent Mechanical Properties in Polyetherimide 3D-Printed Parts Are Dictated by Isotropic Performance Being Accurately Predicted by the Generalized Time Hardening Model. Polymers 2020, 12, 678 .
AMA StyleA. G. Salazar-Martín, A. A. García-Granada, G. Reyes, G. Gomez-Gras, J. M. Puigoriol-Forcada. Time-Dependent Mechanical Properties in Polyetherimide 3D-Printed Parts Are Dictated by Isotropic Performance Being Accurately Predicted by the Generalized Time Hardening Model. Polymers. 2020; 12 (3):678.
Chicago/Turabian StyleA. G. Salazar-Martín; A. A. García-Granada; G. Reyes; G. Gomez-Gras; J. M. Puigoriol-Forcada. 2020. "Time-Dependent Mechanical Properties in Polyetherimide 3D-Printed Parts Are Dictated by Isotropic Performance Being Accurately Predicted by the Generalized Time Hardening Model." Polymers 12, no. 3: 678.
The use of support material to produce Fused Deposition Modeling parts is often unavoidable. The support removal task tends to be laborious and time-consuming when no soluble support materials are available, which is the case of the high-performance thermoplastic Ultem™ 9085. This paper investigates the effect of different solvent/solvent mixtures on Ultem’s mechanical properties with the aim to identify a solvent capable of dissolving its support material (a polysulfone) without noticeably damaging the model material. To do so, initial solubility tests have helped narrow the list of solvent candidates. These have been followed by infrared analyses to identify the presence of dissolved polymers in the media, as well as scanning electron microscope micrographs to analyze the surface topography of the treated parts. Finally, tensile and flexural tests have permitted to quantify the change on Ultem’s mechanical properties as a function of the treatment time. Major findings include a reproducible method for softening or eliminating Ultem’s support material with non-significant changes in their mechanical properties. The outcome of this work represents a first step on the lookout for a solution to facilitate the removal of polysulfone and is considered of great interest for the scientific community due to the rise of Ultem as a structural material.
Ariadna Chueca de Bruijn; Giovanni Gómez-Gras; Marco A. Pérez. Mechanical study on the impact of an effective solvent support-removal methodology for FDM Ultem 9085 parts. Polymer Testing 2020, 85, 106433 .
AMA StyleAriadna Chueca de Bruijn, Giovanni Gómez-Gras, Marco A. Pérez. Mechanical study on the impact of an effective solvent support-removal methodology for FDM Ultem 9085 parts. Polymer Testing. 2020; 85 ():106433.
Chicago/Turabian StyleAriadna Chueca de Bruijn; Giovanni Gómez-Gras; Marco A. Pérez. 2020. "Mechanical study on the impact of an effective solvent support-removal methodology for FDM Ultem 9085 parts." Polymer Testing 85, no. : 106433.
This paper aims to analyse the mechanical properties response of polylactic acid (PLA) parts manufactured through fused filament fabrication. The influence of six manufacturing factors (layer height, filament width, fill density, layer orientation, printing velocity, and infill pattern) on the flexural resistance of PLA specimens is studied through an L27 Taguchi experimental array. Different geometries were tested on a four-point bending machine and on a rotating bending machine. From the first experimental phase, an optimal set of parameters deriving in the highest flexural resistance was determined. The results show that layer orientation is the most influential parameter, followed by layer height, filament width, and printing velocity, whereas the fill density and infill pattern show no significant influence. Finally, the fatigue fracture behaviour is evaluated and compared with that of previous studies’ results, in order to present a comprehensive study of the mechanical properties of the material under different kind of solicitations.
J. Antonio Travieso-Rodriguez; Ramon Jerez-Mesa; Jordi Llumà; Oriol Traver-Ramos; Giovanni Gomez-Gras; Joan Josep Roa Rovira. Mechanical Properties of 3D-Printing Polylactic Acid Parts subjected to Bending Stress and Fatigue Testing. Materials 2019, 12, 3859 .
AMA StyleJ. Antonio Travieso-Rodriguez, Ramon Jerez-Mesa, Jordi Llumà, Oriol Traver-Ramos, Giovanni Gomez-Gras, Joan Josep Roa Rovira. Mechanical Properties of 3D-Printing Polylactic Acid Parts subjected to Bending Stress and Fatigue Testing. Materials. 2019; 12 (23):3859.
Chicago/Turabian StyleJ. Antonio Travieso-Rodriguez; Ramon Jerez-Mesa; Jordi Llumà; Oriol Traver-Ramos; Giovanni Gomez-Gras; Joan Josep Roa Rovira. 2019. "Mechanical Properties of 3D-Printing Polylactic Acid Parts subjected to Bending Stress and Fatigue Testing." Materials 12, no. 23: 3859.
This paper aims to analyse the mechanical properties response of polylactic acid (PLA) parts manufactured through fused filament fabrication. The influence of six manufacturing factors (layer height, filament width, fill density, layer orientation, printing velocity, and infill pattern) on the flexural resistance of PLA specimens is studied through an L27 Taguchi experimental array. Different geometries have been tested on a four-point bending machine and on a rotating bending machine. From the first experimental phase, an optimal set of parameters deriving in the highest flexural resistance have been determined. Results show that layer orientation is the most influential parameter, followed by layer height, filament width, and printing velocity, whereas the fill density and infill pattern show no significant influence. Finally, the fatigue fracture behaviour is evaluated and compared with previous studies results, to present a comprehensive study of the mechanical properties of the material under different kind of solicitations.
J. Antonio Travieso-Rodriguez; Ramon Jerez-Mesa; Jordi Llumà; Oriol Traver-Ramos; Giovanni Gomez-Gras; Joan Josep Roa Rovira. Mechanical Properties of 3D-Printing Polylactic Acid Parts Subjected to Bending Stress and Fatigue Testing. 2019, 1 .
AMA StyleJ. Antonio Travieso-Rodriguez, Ramon Jerez-Mesa, Jordi Llumà, Oriol Traver-Ramos, Giovanni Gomez-Gras, Joan Josep Roa Rovira. Mechanical Properties of 3D-Printing Polylactic Acid Parts Subjected to Bending Stress and Fatigue Testing. . 2019; ():1.
Chicago/Turabian StyleJ. Antonio Travieso-Rodriguez; Ramon Jerez-Mesa; Jordi Llumà; Oriol Traver-Ramos; Giovanni Gomez-Gras; Joan Josep Roa Rovira. 2019. "Mechanical Properties of 3D-Printing Polylactic Acid Parts Subjected to Bending Stress and Fatigue Testing." , no. : 1.
The expansion of 3D printing systems as mechatronic devices able to localize manufacturing activities has attracted the attention in academic and professional labs worldwide. However, little is known from a formal point of view about the actual possibilities of optimization in terms of hardware and software. This paper proposes alternative geometrical designs of RepRap 3D printer liquefiers, and offers an evaluation of their thermal performance by analyzing the temperature profiles derived from their functioning in a steady state regime. For that purpose, finite element calculation and experimental techniques are combined and compared. A detachable model of liquefier, used in numerous RepRap 3D printers, has been taken as a reference to design and manufacture two new variations. As the objective of the liquefier is to heat the plastic material while limiting the temperature at its top, heat conduction must be prevented by means of a refrigerating fan faced at the liquefier body. The effect of that fan has been introduced in the system of study, by evaluating the influence of five different fan velocities on the final temperature profile. All combinations of fan speed and liquefier geometry have been calculated through a finite elements model. Then, they have been reproduced experimentally, measuring discrete temperatures at different heights of the liquefier by a group of thermocouples installed on the surface of the fins composing the liquefier heat sink. Results showed that the defined FEM model reproduces acceptably the final temperature profiles obtained by experimental measures. Furthermore, the new proposed design provided with thick fins shows its good performance when the 3D printing process is performed with a fan speed higher than 10% (defined according to a PWM function programmed at the 3D printer's firmware), while its design presents a much lower manufacturing time with regards to the present available design. It is also concluded that refrigerating the liquefier during a standard 3D printing process with an airflow higher than PWM¿=¿20% is not recommended, due to a fall in efficiency and not remarkable refrigerating effect obtained through it.Postprint (author's final draft
R. Jerez-Mesa; G. Gomez-Gras; J.A. Travieso-Rodriguez; V. Garcia-Plana. A comparative study of the thermal behavior of three different 3D printer liquefiers. Mechatronics 2018, 56, 297 -305.
AMA StyleR. Jerez-Mesa, G. Gomez-Gras, J.A. Travieso-Rodriguez, V. Garcia-Plana. A comparative study of the thermal behavior of three different 3D printer liquefiers. Mechatronics. 2018; 56 ():297-305.
Chicago/Turabian StyleR. Jerez-Mesa; G. Gomez-Gras; J.A. Travieso-Rodriguez; V. Garcia-Plana. 2018. "A comparative study of the thermal behavior of three different 3D printer liquefiers." Mechatronics 56, no. : 297-305.
This paper aims to analyze the fatigue response of PLA parts manufactured through fused filament fabrication (FFF). The influence of four factors (layer height, fill density, nozzle diameter and velocity) on the fatigue performance of cylindrical specimens is studied through an L27 Taguchi experimental design. This design is run for two different infills: linear and honeycomb. Specimens have been tested on a rotating fatigue bending machine. The optimal set of parameters and levels resulting in the highest number of cycles to failure have been determined, and implemented to manufacture a second set of specimens, which have been tested at different stress levels to represent the Wöhler curve. Fill density proves to be the most influential parameter on fatigue life, followed by layer height. The tests undertaken to represent the Wöhler curve revealed that 35.8 MPa can be considered as a lower threshold of the endurance limit for this kind of specimens. This value can be useful to use these devices to manufacture human implants, as PLA is a biocompatible material. The main novelty of this paper is that no previous fatigue life assessment of PLA parts manufactured through FFF has been developed.Peer ReviewedPostprint (author's final draft
Giovanni Gomez-Gras; Ramón Jerez-Mesa; J. Antonio Travieso-Rodriguez; Jordi Lluma-Fuentes. Fatigue performance of fused filament fabrication PLA specimens. Materials & Design 2018, 140, 278 -285.
AMA StyleGiovanni Gomez-Gras, Ramón Jerez-Mesa, J. Antonio Travieso-Rodriguez, Jordi Lluma-Fuentes. Fatigue performance of fused filament fabrication PLA specimens. Materials & Design. 2018; 140 ():278-285.
Chicago/Turabian StyleGiovanni Gomez-Gras; Ramón Jerez-Mesa; J. Antonio Travieso-Rodriguez; Jordi Lluma-Fuentes. 2018. "Fatigue performance of fused filament fabrication PLA specimens." Materials & Design 140, no. : 278-285.
Andres Amador García-Granada; Giovanni Gomez-Gras; Ramón Jerez-Mesa; J. Antonio Travieso-Rodriguez; Guillermo Reyes. Ball-burnishing effect on deep residual stress on AISI 1038 and AA2017-T4. Materials and Manufacturing Processes 2017, 32, 1279 -1289.
AMA StyleAndres Amador García-Granada, Giovanni Gomez-Gras, Ramón Jerez-Mesa, J. Antonio Travieso-Rodriguez, Guillermo Reyes. Ball-burnishing effect on deep residual stress on AISI 1038 and AA2017-T4. Materials and Manufacturing Processes. 2017; 32 (11):1279-1289.
Chicago/Turabian StyleAndres Amador García-Granada; Giovanni Gomez-Gras; Ramón Jerez-Mesa; J. Antonio Travieso-Rodriguez; Guillermo Reyes. 2017. "Ball-burnishing effect on deep residual stress on AISI 1038 and AA2017-T4." Materials and Manufacturing Processes 32, no. 11: 1279-1289.
The aim of this paper is to analyze the performance of a RepRap 3D printer liquefier by studying its thermal behavior, focusing on the convective heat dissipation developed along the liquefier body during the 3D printing process of a workpiece. More specifically, this work tackles with the influence of the airflow generated by a fan coupled to the extruder, on the heat transfer mechanisms during the printing process. The airflow is thus taken as the variable of study. The temperature at the top of the liquefier body, where a low temperature is desirable for the correct preservation of the 3D printer components, is analyzed to assess the results for the different printing conditions. For the development of this study, a finite elements model was used to determine the theoretical temperature profile of the liquefier in a steady state working regime. This mathematical model was then validated with experimental data registered with four thermocouples fixed on the tested extruder. The data was taken for different airflows, finding a relation between printing parameters and resulting temperature profile. The liquefier used for experimental data acquisition was the BCNozzle model, designed by the BCN3D Technologies of the Polytechnic University of Catalonia. Determining the correct working parameters is necessary to optimize the fused filament fabrication process on which 3D printing is based, ensuring a suitable temperature distribution along the liquefier body. This would allow a correct position of the melting front along the liquefier channel, and at the same time, a non-excessive temperature at its top, next to the feeding mechanism. This is the relevance of this study, through which a model is obtained to analyze the heat transfer mechanisms, applicable for other working regimes and other extruders based on the same working principles.
R. Jerez-Mesa; J.A. Travieso-Rodriguez; X. Corbella; R. Busqué; G. Gomez-Gras. Finite element analysis of the thermal behavior of a RepRap 3D printer liquefier. Mechatronics 2016, 36, 119 -126.
AMA StyleR. Jerez-Mesa, J.A. Travieso-Rodriguez, X. Corbella, R. Busqué, G. Gomez-Gras. Finite element analysis of the thermal behavior of a RepRap 3D printer liquefier. Mechatronics. 2016; 36 ():119-126.
Chicago/Turabian StyleR. Jerez-Mesa; J.A. Travieso-Rodriguez; X. Corbella; R. Busqué; G. Gomez-Gras. 2016. "Finite element analysis of the thermal behavior of a RepRap 3D printer liquefier." Mechatronics 36, no. : 119-126.
This paper explores the effects on the surface roughness, hardness and residual\ud stress of G10380 steel specimens milled and treated with a ball-burnishing process\ud assisted by vibrations. These vibrations are incorporated through the attachment of an\ud induced coil module to a conventional burnishing tool, with forces transmitted through a\ud pre-loaded spring. A positive effect of vibrations on the improvement and efficiency of\ud the burnishing treatment is demonstrated, empirically proving that the vibrations\ud introduce additional energy into the system that aids with displacements along the\ud surface of the material to reallocate the crystalline structure. Significant results are\ud found in terms of final surface roughness, which is highly improved in comparison to\ud conventional burnishing treatments, even with fewer passes and a significant time\ud reduction. Less robust results are observed in terms of specimen hardness and\ud residual stress, but future improvements could be derived with a thorough development\ud of the vibration system.Postprint (author's final draft
Jose Antonio Travieso-Rodriguez; Giovanni Gomez-Gras; Gilles Dessein; Francisco Carrillo; Joël Alexis; Jordi Jorba Peiró; Nathalie Aubazac. Effects of a ball-burnishing process assisted by vibrations in G10380 steel specimens. The International Journal of Advanced Manufacturing Technology 2015, 81, 1757 -1765.
AMA StyleJose Antonio Travieso-Rodriguez, Giovanni Gomez-Gras, Gilles Dessein, Francisco Carrillo, Joël Alexis, Jordi Jorba Peiró, Nathalie Aubazac. Effects of a ball-burnishing process assisted by vibrations in G10380 steel specimens. The International Journal of Advanced Manufacturing Technology. 2015; 81 (9-12):1757-1765.
Chicago/Turabian StyleJose Antonio Travieso-Rodriguez; Giovanni Gomez-Gras; Gilles Dessein; Francisco Carrillo; Joël Alexis; Jordi Jorba Peiró; Nathalie Aubazac. 2015. "Effects of a ball-burnishing process assisted by vibrations in G10380 steel specimens." The International Journal of Advanced Manufacturing Technology 81, no. 9-12: 1757-1765.
This paper aims to find the key process parameters for machining different parts of an automobile gearbox, commissioned by a company that needs to replace with the MQL lubrication system their current machining process based on cutting fluids. It particularly focuses on the definition of appropriate cutting parameters for machining under the MQL condition through a statistical method of Design of Experiments (DOE). Using a combination of recommended parameters, significant improvements in the surface roughness of different machined parts are shown. Production costs are also reduced by decreasing expenses on lubricants and by optimizing the cycle time reached under the new cutting conditions, what would help the implementing company to increase its profits and adapt to a modern sustainability-demanding production industry.
J. Antonio Travieso-Rodriguez; Giovanni Gomez-Gras; Silvia Garcia-Vilana; Ferran Mainau-Noguer; Ramón Jerez-Mesa. Characterization of Cutting Parameters in the Minimum Quantity Lubricant (MQL) Machining Process of a Gearbox. International Journal of Manufacturing, Materials, and Mechanical Engineering 2015, 5, 49 -60.
AMA StyleJ. Antonio Travieso-Rodriguez, Giovanni Gomez-Gras, Silvia Garcia-Vilana, Ferran Mainau-Noguer, Ramón Jerez-Mesa. Characterization of Cutting Parameters in the Minimum Quantity Lubricant (MQL) Machining Process of a Gearbox. International Journal of Manufacturing, Materials, and Mechanical Engineering. 2015; 5 (1):49-60.
Chicago/Turabian StyleJ. Antonio Travieso-Rodriguez; Giovanni Gomez-Gras; Silvia Garcia-Vilana; Ferran Mainau-Noguer; Ramón Jerez-Mesa. 2015. "Characterization of Cutting Parameters in the Minimum Quantity Lubricant (MQL) Machining Process of a Gearbox." International Journal of Manufacturing, Materials, and Mechanical Engineering 5, no. 1: 49-60.