Mechanical Engineering, Mechanics of Materials, Engineering, Industrial and Manufacturing Engineering
56
Scopus Publications
Scopus Publications
Characterisation and performance of coated SiAlON cutting tools for Inconel 718 machining Beatriz G. Rodrigues, Beatriz Monteiro, Sónia Simões, Ana Reis, Tiago Silva, Bruno Guimarães, Tomás Aires, Cristina M. Fernandes, Daniel Figueiredo Surface and Coatings Technology, 2026 Physical vapor deposition (PVD) with High Power Impulse Magnetron Sputtering (HiPIMS) presents a highly promising surface modification approach for the performance enhancement of SiAlON cutting tools in the machining of Nickel-based superalloys alloys, which are renowned for their challenging machinability. This study systematically investigates the coating roughness, microstructural characteristics, and cutting performance of HiPIMS-coated SiAlON tools in Inconel 718 milling. The deposited multilayer coatings were comprehensively analysed using advanced characterisation techniques, including scanning electron microscopy (SEM) and energy dispersive X-ray spectroscopy (EDS). Cutting tests were carried out with different tool geometries and machining conditions, as well as coated and uncoated tools—factors that highly influence tool's performance. The HiPIMS coating demonstrated improved thermal stability and reduced susceptibility to diffusion-related deterioration—factors that are critical in managing the high temperatures encountered in superalloy machining. These results underscore the potential of HiPIMS technology to significantly extend tool longevity and enhance machining efficiency, establishing it as a viable solution for high-performance manufacturing sectors. • Coated SiAlON tools studied for high-speed machining of Inconel 718 superalloy • Coating effectiveness depends on tool geometry; improved performance for RPGN 090300. • Wear mechanisms include adhesion, notch wear, chipping, and built-up edge formation. • No significant diffusion wear detected; material transfer confirmed by EDS analysis • Coated tools enable high material removal rates at speeds ≥800 m/min with optimization.
Advanced ceramic multilayer coatings for increasing the tool life of cutting inserts: A hybrid CVD-PVD approach Teodor-Cezar Codau, João Ferreira, Ana V. Girão, Elena Codau, Daniel Figueiredo, Cristina M. Fernandes, Bruno Guimarães, Filipe J. Oliveira Materials Chemistry and Physics, 2026 The manufacturing sector faces significant challenges in efficiency, adaptability, and sustainability, with cutting tool performance being critical for both production processes and final product quality. The development of new multilayer coatings for cutting tools has become a constant concern in today's industrial landscape, driven by the need for enhanced tool life and improved machining efficiency in increasingly demanding applications. In this study, multilayer structures were designed with TiN (<0.3 μm)/TiCN (4 μm)/Al 2 O 3 (3 μm)/TiN (1 μm) base layers deposited via CVD, followed by AlCrN (4 μm) or AlCrN (3 μm) + ZrN (1 μm) applied via PVD-HiPIMS. The textured Al 2 O 3 intermediate layer exhibited a preferred (006) crystallographic orientation, typically associated with enhanced hardness of the CVD layer. Energy Dispersive X-ray Spectroscopy (EDS) and tribological tests demonstrated lower adhesion of workpiece materials and improved wear resistance for the hybrid coatings compared to conventional CVD coatings. Machining tests on AISI 316 stainless steel during a turning operation revealed that the hybrid-coated tools exhibited significantly better tool life compared to the CVD-coated tools (by 69.20%), considering a flank wear of VB = 0.134 mm as the end-of-life criterion. These results provide strong evidence that the hybrid CVD/PVD multilayer coating strategy significantly enhances cutting tool performance and longevity in demanding machining applications. • Hybrid CVD-PVD Approach: Development of advanced ceramic multilayer coatings using a combination of Chemical Vapor Deposition (CVD) and High-Power Impulse Magnetron Sputtering (HiPIMS)-based Physical Vapor Deposition (PVD) for enhanced tool life. • Optimized Crystallographic and Coating Properties: The study demonstrates the importance of crystallographic orientation and coating density in improving the wear resistance of cutting inserts, with a focus on TiN/TiCN/Al 2 O 3 /TiN multilayers. • Superior Tool Performance: Machining tests on stainless steel show a direct correlation between the new coatings and a significant increase in tool life, highlighting their potential to boost efficiency and durability in industrial applications.
Development of a Workflow for Topological Optimization of Cutting Tool Milling Bodies Bruno Rafael Cunha, Bruno Miguel Guimarães, Daniel Figueiredo, Manuel Fernando Vieira, José Manuel Costa Metals, 2026 This study establishes a systematic and reproducible workflow for topology optimization (TO) of indexable face milling cutter bodies with integrated internal coolant channels, designed for Additive Manufacturing (AM) of metallic parts. Grounded in Design for Additive Manufacturing (DfAM) principles, the workflow combines displacement-based TO and computational fluid dynamics analysis to generate simulation-driven tool geometries tailored to the constraints of AM. By leveraging iterative design knowledge, the proposed methodology enhances the scalability and repeatability of the design process, reducing development time and supporting rapid adaptation across various tool geometries. AM is explicitly exploited to integrate support-free internal coolant channels directed toward the insert cutting edge, thereby achieving a 20% mass reduction relative to the initial milling tool designs, and improving material usage efficiency at the design stage. The workflow yields numerically optimized geometries that maintain simulated global stiffness under the considered loading conditions and exhibit coolant flow distributions that effectively target the exposed cutting edges. These simulation results demonstrate the feasibility of an AM oriented, workflow-based approach for the numerical design of milling tools with internal cooling, mass reduction and provide a focused basis for subsequent experimental validation and comparison with conventionally manufactured counterparts.
Precision milling of zirconia toughened alumina (ZTA) with HF-CVD endmill tool Daniel Figueiredo, M.F.R.P. Alves, Tiago E.F. Silva, S.M. Olhero, Bruno Guimarães, C.M. Fernandes, J. Paulo Davim Ceramics International, 2026 Sintered ceramics are recognized as promising materials for high-precision and advanced applications, such as orthopedic grafts implants, owing to their superior mechanical performance and biocompatibility. The fabrication of complex or intricate geometries often necessitates post-processing, for which micro-milling is frequently utilized. This paper focuses on the micro-milling of zirconia-toughened alumina (ZTA), a high-performance ceramic widely used in the medical industry for joint implants and rehabilitation components. The study investigates the surface formation mechanisms, size effects, and chip thickness characteristics associated with the process. In addition, the performance of cemented carbide micro-milling tools coated with a multi-layer HF-CVD diamond film is evaluated to assess their suitability for precision machining of ZTA ceramics. The tool wear mechanisms were systematically investigated, with particular attention given to the main failure modes occurring during the micro-milling process, including coating deterioration of the cutting tool. The surface formation and damage behaviour of ZTA under various cutting conditions were analysed in detail. Experimental results demonstrate that ZTA can be efficiently machined by micro-milling under controlled cutting parameters, achieving high surface quality and an industrially relevant tool life. The micro-milling of sintered ceramics remains challenging due to their inherent high strength and brittleness. Attaining the desired surface integrity and dimensional accuracy requires further optimization of machining parameters and strategies. Key aspects include the control of ductile-regime machining and the reduction of cutting near the tool center, both of which are critical to achieving improved performance.
Innovative approach for assessing ultra-low wear in tribological tests of advanced ceramic-coated inserts Teodor Cezar Codau, Jorge Santos, Ana V. Girão, Elena Codau, Daniel Figueiredo, Cristina M. Fernandes, Bruno Guimarães, Filipe J. Oliveira Ceramics International, 2026 Tribological testing is essential for evaluating the performance and reliability of advanced ceramic multilayer-coated tools. Unlike conventional materials, coated inserts are designed to enhance hardness, thermal stability, and resistance to wear and friction. Owing to these properties, accurate specific wear rate determination becomes challenging, primarily due to the very small depth of the resulting wear tracks. In this study, a new wear evaluation method based on Material Ratio Curve Integration (MCI) is proposed. Reciprocating ball-on-flat tribological tests were performed on cemented tungsten carbide (WC–Co) samples coated with multilayer ceramic films produced using both physical and chemical vapor-based deposition techniques. Wear behavior was analyzed using high-resolution optical profilometry, and wear volumes were quantified using three approaches: the Averaging Cross-Section (ACS) method, following the procedure outlined in ASTM G133-05; Direct Volume Calculation (DVC), based on the integration of cross-sectional profiles along the wear track length; and the newly proposed MCI method. The accuracy, limitations, and reliability of each method were systematically evaluated. The MCI method was validated for sufficiently large wear track depths, showing very good agreement with results obtained using the DVC method implemented using dedicated functions in SensoMAP®. The main advantages of MCI-method are its applicability when other methods fail (e.g., very shallow wear tracks) and the reduced operator dependence.
Robot Path Planning: from Analytical to Computer Intelligence Approaches Pedro A. Dias, João Pedro Carvalho de Souza, E. J. Solteiro Pires, Vítor Filipe, Daniel Figueiredo, Luís F. Rocha, Manuel F. Silva Journal of Intelligent and Robotic Systems Theory and Applications, 2025 In an era where robots are becoming an integral part of human quotidian activities, understanding how they function is crucial. Among the inherent building complexities, from electronics to mechanics, path planning emerges as a universal aspect of robotics. The primary contribution of this work is to provide an overview of the current state of robot path planning topics and a comparison between those same algorithms and its inherent characteristics. The path planning concept relies on the process by which an algorithm determines a collision-free path between a start and an end point, optimizing parameters such as energy consumption and distance. The quest for the most effective path planning method has been a long-standing discussion, as the choice of method is highly dependent on the specific application. This review consolidates and elucidates the categories of path planning methods, specifically classical or analytical methods, and computer intelligence methods. In addition, the operational principles of these categories will be explored, discussing their respective advantages and disadvantages, and reinforcing these discussions with relevant studies in the field. This work will focus on the most prevalent and recognized methods within the robotics path planning problem, being mobile robotics or manipulator arms, including Cell Decomposition, A*, Probabilistic Roadmaps, Rapidly-exploring Random Trees, Genetic Algorithms, Particle Swarm Optimization, Ant Colony Optimization, Artificial Potential Fields, Fuzzy, and Neural Networks. Following the detailed explanation of these methods, a comparative analysis of their advantages and drawbacks is organized in a comprehensive table. This comparison will be based on various quality metrics, such as the type of trajectory provided (global or local), the scenario implementation type (real or simulated scenarios), testing environments (static or dynamic), hybrid implementation possibilities, real-time implementation, completeness of the method, consideration of the robot’s kinodynamic constraints, use of smoothing techniques, and whether the implementation is online or offline.
Insights of Direct Ink Writing parameters towards dense silicon nitride manufacturing M.S. Faria, M.J. Pereira, M.F.P. Alves, C.M. Fernandes, D. Figueiredo, F.J. Oliveira, S.M. Olhero Journal of Manufacturing Processes, 2025 This study investigates the influence of printing parameters such as infill patterning (0° and 90°), nozzle diameter (0.41, 0.33, 0.25 and 0.15 mm) and printing speed (5–25 mm.s −1 ), on the printability of Si 3 N 4 parts by Direct Ink Writing (DIW). Firstly, a fixed paste composition was used to evaluate the effect of infill direction, nozzle diameter and post processing (cold isostatic pressing) in the final density, flexural strength and hardness of printed samples. Then, a map was constructed by relating printability with the nozzle diameter and the printing speed. Lastly, the paste composition was adjusted, by controlling the concentration of additives and solids, to improve the printability for small tip diameters (<0.41 mm). Average sintered relative densities of ≈97 % and ≈550 MPa of flexural strength were attained for samples printed with 0.33 mm tip nozzle diameter, using 0° infill direction, reaching ≈99 % and ≈600 MPa with cold isostatic pressing as post processing. Further decrease in nozzle diameter size to 0.25 mm resulted in high variability for both densification and flexural strength, because of the high quantity of macrodefects arising from the printing process, highlighting the need to adjust the rheological properties of the ink for a proper extrudability. Increasing the amount of carboxymethyl cellulose in the paste with 37 vol% of solids, increases its stiffness and consequently, larger shear forces are required to induce flow, without phase separation.
Enhancing the cutting performance of laser surface textured WC–Co cutting tools—a study on AISI 316L stainless steel turning Bruno Guimarães, Francisco Marques, Cristina Fernandes, Daniel Figueiredo, Filipe Silva, Georgina Miranda International Journal of Advanced Manufacturing Technology, 2025 During machining processes, cutting tools suffer severe tool wear, due to the friction generated at the tool-chip and tool-workpiece interfaces that produce a considerable amount of abrasion and heat in the cutting zone. Surface texturing has the ability to improve the cutting performance of cutting tools by providing enhanced lubricant availability to the inaccessible area of the tool-chip interface, increasing load carrying capacity, enhancing wetting properties and heat transfer coefficient and reducing the tool-chip contact area and chip on tool contact length, thus reducing friction, tool wear and cutting temperature and forces. This study presents a novel surface modification approach for fabricating cross-hatched micropatterns on the rake face of WC–Co cutting inserts, consisting in performing the laser surface texturing process in the green body of the inserts. The addition of micropatterns to WC–Co cutting tools decreased tool wear by 33%, when compared to a commercial cutting tool during turning of AISI 316L stainless steel, due to the improved ability to extract more heat in the cutting zone and nearer to the cutting edge, increased lubrication effect and reduced tool-chip contact area and length. Therefore, the findings obtained in this study are crucial for future developments of cutting tools with novel designs and features.
Optimising WC-25Co Feedstock and Parameters for Laser-Directed Energy Deposition Helder Nunes, José Nhanga, Luís Regueiras, Ana Reis, Manuel F. Vieira, Bruno Guimarães, Daniel Figueiredo, Cristina Fernandes, Omid Emadinia Journal of Manufacturing and Materials Processing, 2025 Laser-Directed Energy Deposition (L-DED) is an additive manufacturing technique used for producing and repairing components, mainly for coating applications, depositing metal matrix composites such as cemented carbides, composed of hard metal carbides and a metallic binder. In this sense, this study evaluated the preparation of a ready-to-press WC-25Co powder as a reliable feedstock for L-DED process. This powder required pre-heat treatment studies to prevent fragmentation during powder feeding, due to the absence of metallurgical bonding between WC and Co particles. In the current study, the Taguchi methodology was used, varying laser power, powder feed rate, and scanning speed to reach an optimised deposition window. The best bead morphology resulted from 2400 W laser power, 11 mm/s scanning speed, and 9 g/min feed rate. Moreover, defects such as porosity and cracking were mitigated by applying a remelting strategy of 2400 W and 9 mm/s. Therefore, a perfect deposition is obtained using the optimised processing parameters. Microstructural analysis of the optimised deposited line revealed a fine structure, comprising columnar and equiaxed dendrites of complex carbides. The average hardness of the deposited WC-25Co powder on a AISI 1045 steel was 854 ± 37 HV0.2. These results demonstrate the potential of L-DED for processing high-performance cemented carbide coatings.
Impact Of Binder Selection On Binder Jetting Of Hard Metal Parts , Naiara Azurmendi, , Iñigo Agote, , Xabier Gómez, , Irati Zurutuza, , Cristina Fernandes, , Daniel Figueiredo,, Bruno Guimarães Euro Powder Metallurgy 2025 Congress and Exhibition Euro Pm 2025, 2025
WC-Co Versus Ticn/WC-Co, Ni For New Cutting Tools Gonçalo Oliveira, Ricardo Mineiro, Ana Maria Rocha Senos, Cristina Fernandes, Daniel Figueiredo, Teresa Vieira Maria Euro Powder Metallurgy 2023 Congress and Exhibition Pm 2023, 2023
Development of Low PcBN Composites by SPS Ricardo Mineiro, J. Rodrigues, C.M. Fernandes, D. Figueiredo, B. Ferrari, A.J. Sanchez-Herencia, A.M.R. Senos Euro Powder Metallurgy 2023 Congress and Exhibition Pm 2023, 2023
Binder Jetting Of Hardmetals: A Comparative Study Of Microstructures And Properties Of Different Commercial Powders World Pm 2022 Congress Proceedings, 2022
Indirect Additive Manufacturing (Material Extrusion) as a Solution to a New Concept of Cutting Tools World Pm 2022 Congress Proceedings, 2022
Properties gradient in hardmetal parts achieved with recycled powders Euro Pm 2018 Congress and Exhibition, 2020
The Effect of Carbon Content on the Properties Gradient of Hardmetal Parts Attained with Recycled Powders Proceedings Euro Pm2020 Congress and Exhibition, 2020
Influence of Secondary Carbides on Ticn Based Cermets Compositions Proceedings Euro Pm2020 Congress and Exhibition, 2020
The effect of surface texturing on the temperature distribution on WC-Co cutting tools Proceedings Euro Pm2020 Congress and Exhibition, 2020
Chemical pretreatment optimization for improved diamond adhesion on hard metal substrates Proceedings Euro Pm2020 Congress and Exhibition, 2020
Recovering of hardmetal powder into hardmetal rods and development of gradient properties Euro Pm 2019 Congress and Exhibition, 2019
Optimization of cutting parameters to minimize the surface roughness in the end milling process using the Taguchi method Department of Mechanical Technology, Polytechnic Institute of Bragança, Portugal, João Ribeiro, Hernâni Lopes, Department of Mechanical Engineering, Polytechnic Institute of Porto, Portugal, Luis Queijo, Department of Mechanical Technology, Polytechnic Institute of Bragança, Portugal, Daniel Figueiredo, Development Department, Palbit, Hardmetals Tools Solutions, Portugal Periodica Polytechnica Mechanical Engineering, 2017
