Five-Axis Milling of Large Spiral Bevel Gears: Toolpath Definition, Finishing, and Shape Errors

In this paper, a five-axis machining process is analyzed for large spiral-bevel gears, an interesting process for one-of-kind manufacturing. The work is focused on large sized spiral bevel gears manufacturing using universal multitasking machines or five-axis milling centers. Different machining strategies, toolpath patterns, and parameters are tested for both gear roughing and finishing operations. Machining time, tools' wear, and gear surface are analyzed in order to determine which are the best strategies and parameters for large modulus gear manufacturing on universal machines. The case study results are discussed in the last section, showing the capacity of a universal five-axis milling for this niche. Special attention was paid to the possible affectations of the metal surfaces, since gear durability is very sensitive to thermo-mechanical damage, affected layers, and flank gear surface state.Thanks are addressed to the Department of Education, and to the Universities and Research of the Basque Government for their financial support, by means of the ZABALDUZ program. We thank also the UFI in Mechanical Engineering department of the UPV/EHU for its support to this project

Five-Axis Milling of Large Spiral Bevel Gears: Toolpath Definition, Finishing, and Shape Errors

In this paper, a five-axis machining process is analyzed for large spiral-bevel gears, an interesting process for one-of-kind manufacturing. The work is focused on large sized spiral bevel gears manufacturing using universal multitasking machines or five-axis milling centers. Different machining strategies, toolpath patterns, and parameters are tested for both gear roughing and finishing operations. Machining time, tools' wear, and gear surface are analyzed in order to determine which are the best strategies and parameters for large modulus gear manufacturing on universal machines. The case study results are discussed in the last section, showing the capacity of a universal five-axis milling for this niche. Special attention was paid to the possible affectations of the metal surfaces, since gear durability is very sensitive to thermo-mechanical damage, affected layers, and flank gear surface state.Thanks are addressed to the Department of Education, and to the Universities and Research of the Basque Government for their financial support, by means of the ZABALDUZ program. We thank also the UFI in Mechanical Engineering department of the UPV/EHU for its support to this project

The Gender Perspective of Professional Competencies in Industrial Engineering Studies

Sexism and gender relations in higher education require special attention and are a topic of great interest in regulations related to education. The low participation percentage of women in Science, Technology, Engineering, and Mathematics (STEM) studies has been identified as one of the main problems that must be resolved in order to close the gender gap that exists in the technology sector. The purpose of this study was to investigate the influence of professional competences on the selection of university studies according to the absence or presence of masculinization factors in those studies. Mechanical engineering competences, both generic and transversal, and competence acquisition methods, are classified into ‘care’ (feminine) or ‘provisions’ (masculine) concepts. After the competence analysis, it can be concluded that explicit engineering curricula are focused on “provisions”, which translates into a cultural perception of industrial engineering as a male profession. After a professional competence analysis in engineering studies at The University of the Basque Country (UPV/EHU), our study identified a relationship between the masculinization factors included in professional competences and the selection of university studies. This paper presents working actions towards the incorporation of a gender perspective into the degree in mechanical engineering at the UPV/EHU.This research was funded by PIE (Educational Innovation Projects) program of the University of the Basque Country for their support via 2018–2019 call and grant number [59]

Drilling Process in γ-TiAl Intermetallic Alloys

Gamma titanium aluminides (gamma-TiAl) present an excellent behavior under high temperature conditions, being a feasible alternative to nickel-based superalloy components in the aeroengine sector. However, considered as a difficult to cut material, process cutting parameters require special study to guarantee component quality. In this work, a developed drilling mechanistic model is a useful tool in order to predict drilling force (Fz) and torque (Tc) for optimal drilling conditions. The model is a helping tool to select operational parameters for the material to cut by providing the programmer predicted drilling forces (Fz) and torque (Tc) values. This will allow the avoidance of operational parameters that will cause excessively high force and torque values that could damage quality. The model is validated for three types of Gamma-TiAl alloys. Integral hard metal end-drilling tools and different cutting parameters (feeds and cutting speeds) are tested for three different sized holes for each alloy.RTC-2014-1861-4, INNPACTO DESAFIO II. Spanish Governmen

Hybrid manufacturing of complex components: Full methodology including laser metal deposition (LMD) module development, cladding geometry estimation and case study validation

To optimize and satisfy current industrial requirements, during the last decade new alternatives to conventional manufacturing processes are implemented into conventional machines, leading to multitasking machines. Especially hybrid machines combining additive and subtractive technologies (AM/SM), have become a potential solution for manufacturing and repairing operations in terms of material waste reduction, time consumption and flexibility. Nevertheless, this technology has implications for the machine and the auxiliary elements as well as other challenges: digitalization, process parameterization or CAD/CAM solutions. Thereby, this work proposes a new methodology for hybrid manufacturing systems, a programmed interface to interact between additive and subtractive technologies within the same environment. The developed application programming interface (API) offers a CAM module oriented to AM with appropriate laser metal deposition (LMD) parameters, with three different options of strategy programming: Planar LMD, 3-axis LMD and 5-axis LMD. Additionally, the value of this work stems from the implementation of an algorithm to estimate the cladding geometry, so, the full resulting geometry can be considered as the new blank for SM. A height measuring laser sensor was implemented in the LMD machine to obtain the real height of the generated clad, critical for the next machining step. Finally, to validate the methodology, a blisk made of Hastelloy (R) X was built-up on Inconel (R) 718 with LMD and milled to the final size. Dimensional deviation was measured after each process.This work is based on the grant number [BES-2014-068874] of the Spanish Ministry of Economy and Competitiveness. Also, this work has been sponsored by the H2020-FoF13 PARADDISE Project [Grant Agreement No. 723440]

Hole Making by Electrical Discharge Machining (EDM) of -TiAl Intermetallic Alloys

Due to their excellent strength-to-weight ratio and corrosion and wear resistance, gamma-TiAl alloys are selected for aerospace and automotive applications. Since these materials are difficult to cut and machine by conventional methods, this study performed drilling tests using Electro Discharge Machining (EDM) to compare the machinability between two different types of gamma-TiAl: extruded MoCusi and ingot MoCuSi. Different electrode materials and machining parameters were tested and wear, surface hardness, roughness and integrity were analyzed. The results indicate that extruded MoCuSi is preferable over MoCuSi ingots.Thanks are given to the UFI in Mechanical Engineering of the UPV/EHU for its support to this project, and to Spanish project DPI2016-74845-R, ESTRATEGIAS AVANZADAS DE DEFINICION DE FRESADO EN PIEZAS ROTATIVAS INTEGRALES, CON ASEGURAMIENTO DE REQUISITO DE FIABILIDAD Y PRODUCTIVIDAD and project RTC-2014-1861-4, INNPACTO DESAFIO II

Spiral Bevel Gears Face Roughness Prediction Produced by CNC End Milling Centers

The emergence of multitasking machines in the machine tool sector presents new opportunities for the machining of large size gears and short production series in these machines. However, the possibility of using standard tools in conventional machines for gears machining represents a technological challenge from the point of view of workpiece quality. Machining conditions in order to achieve both dimensional and surface quality requirements need to be determined. With these considerations in mind, computer numerical control (CNC) methods to provide useful tools for gear processing are studied. Thus, a model for the prediction of surface roughness obtained on the teeth surface of a machined spiral bevel gear in a multiprocess machine is presented. Machining strategies and optimal machining parameters were studied, and the roughness model is validated for 3 + 2 axes and 5 continuous axes machining strategies. Palabras claveThank you to the Department of Education, and to the Universities and Research program of the Basque Government for their financial support, by means of the ZABALDUZ program. We also thank the UFI in Mechanical Engineering department of the UPV/EHU for its support of this project

Manufacturing Processes of Integral Blade Rotors for Turbomachinery, Processes and New Approaches

Manufacturing techniques applied to turbomachinery components represent a challenge in the aeronautical sector. These components are commonly composed of high resistant super-alloys; in order to satisfy the extreme working conditions, they have to support during their useful life. Besides, in the particular case of Integrally Bladed Rotors (IBR), they usually present complex geometries that need to be roughed and finished by milling and grinding processes, respectively. Thermoresistant superalloys present many challenges in terms of machinability what leads to find new alternatives to conventional manufacturing processes. In order to face this issue, this work presents a review of the last advances for IBR manufacturing and repairing processes.We are grateful to Basque Excellence university Groups IT IT1337-19, and Ministry of economy project IBRELIABLE (DPI2016-74845-R), and Elkartek PROCODA KK 2019-004

CAM development for additive manufacturing in turbo-machinery components

Additive Manufacturing (AM) has become a constantly growing up technology due to the suitability and flexibility in terms of geometry and material diversity. It is applied in high value damaged part repairs from aeronautical, medical and molds and die sectors. This paper proposes an Application Programing interface(API) to be implemented in a commercial software (NX-Siemens) with the main objective of covering a full solution to AM simulation challenges. Experimental tests were carried out in a case of study in order to verify the suitability and reliability of the developed API. The selected material (Hastelloy X) is an additional challenge to be faced; some trials were performed to obtain optimal parameters for this material. [All rights reserved Elsevier]

Comparison of Flank Super Abrasive Machining vs. Flank Milling on Inconel® 718 Surfaces

Thermoresistant superalloys present many challenges in terms of machinability, which leads to finding new alternatives to conventional manufacturing processes. In order to face this issue, super abrasive machining (SAM) is presented as a solution due to the fact that it combines the advantages of the use of grinding tools with milling feed rates. This technique is commonly used for finishing operations. Nevertheless, this work analyses the feasibility of this technique for roughing operations. In order to verify the adequacy of this new technique as an alternative to conventional process for roughing operations, five slots were performed in Inconel (R) 718 using flank SAM and flank milling. The results showed that flank SAM implies a suitable and controllable process to improve the manufacture of high added value components made by nickel-based superalloys in terms of roughness, microhardness, white layer, and residual stresses.The authors wish to acknowledge the financial support received from the Spanish Ministry of Economy and Competitiveness with the project TURBO (DPI2013-46164-C2-1-R), grant number [BES-2014-068874], to HAZITEK program from the Department of Economic Development and Infrastructures of the Basque Government and from FEDER funds, related to the HEMATEX project and Vice-chancellor of Innovation, Social Compromise and Cultural Action from UPV/EHU (the Bizialab program from the Basque Government). Finally, thanks are also addressed to Spanish Project MINECO DPI2016-74845-R and RTC-2014-1861-4