Submit to Materials Review for Materials Propose a Special Issue

Journal Browser

Hybrid Additive Manufacturing and Machining Machine-Tools and Processes

Special Issue Editors
Special Issue Information
Keywords
Related Special Issue
Published Papers

A special issue of Materials (ISSN 1996-1944). This special issue belongs to the section "Manufacturing Processes and Systems".

Deadline for manuscript submissions: closed (31 May 2020) | Viewed by 66968

Share This Special Issue

Special Issue Editors

Prof. Dr. Aitzol Lamíkiz

E-Mail Website
Guest Editor

Department of Mechanical Engineering, Faculty of Engineering, University of the Basque Country (UPV/EHU), Plaza Torres Quevedo 1, 48013 Bilbao, Bizkaia, Spain
Interests: laser material processing; metal additive manufacturing; laser material deposition; laser process simulation
Special Issues, Collections and Topics in MDPI journals

Prof. Eneko Ukar

E-Mail
Co-Guest Editor

Dpt. of Mechanical Engineering, University of the Basque Country (UPV/EHU), Biscay, Spain
Interests: surface texturing; laser polishing; laser material deposition; selective laser melting; laser process simulation

Special Issue Information

Dear Colleagues,

Hybrid manufacturing systems are becoming an industrial solution for high-complexity part manufacturing. Now, it is possible to observe how main machine tools builders have developed different solutions of hybrid machines that incorporate additive manufacturing and machining processes. The combination of these two processes simultaneously incorporates a series of advantages, such as the possibility of manufacturing very complex parts by adding material and machining details, using the the same fixturing to mafacture the whole part, applying the same CAM system, combining additive manufacturing with high accuracy machining operations, etc.

Therefore, the objective of this Special Issue is the publication of first level research articles in the field of hybrid manufacturing processes, especially those that are applied in advanced materials for the industry. The following topics (not exhaustive) are within the scope of this Special Issue: Experimental research in additive manufacturing and/or machining of parts built by additive manufacturing, simulation of additive manufaturing and hybrid processes, machine solutions and mechatronics adaptations for hybrid systems, process comparison and energy saving using hybrid systems.

Prof. Aitzol Lamíkiz
Prof. Eneko Ukar
Guest Editors

Manuscript Submission Information

Manuscripts should be submitted online at www.mdpi.com by registering and logging in to this website. Once you are registered, click here to go to the submission form. Manuscripts can be submitted until the deadline. All submissions that pass pre-check are peer-reviewed. Accepted papers will be published continuously in the journal (as soon as accepted) and will be listed together on the special issue website. Research articles, review articles as well as short communications are invited. For planned papers, a title and short abstract (about 100 words) can be sent to the Editorial Office for announcement on this website.

Submitted manuscripts should not have been published previously, nor be under consideration for publication elsewhere (except conference proceedings papers). All manuscripts are thoroughly refereed through a single-blind peer-review process. A guide for authors and other relevant information for submission of manuscripts is available on the Instructions for Authors page. Materials is an international peer-reviewed open access semimonthly journal published by MDPI.

Please visit the Instructions for Authors page before submitting a manuscript. The Article Processing Charge (APC) for publication in this open access journal is 2600 CHF (Swiss Francs). Submitted papers should be well formatted and use good English. Authors may use MDPI's English editing service prior to publication or during author revisions.

Keywords

Hybrid Machines
Laser Material Deposition
Additive Manufacturing + Machining
Simulation of Additive Manufacturing
Powder Bed Fusion Processes

Related Special Issue

Additive Manufacturing: Alloy Design and Process Innovations in Materials (63 articles)

Published Papers (13 papers)

Download All Papers

Research

Jump to: Review

16 pages, 3434 KiB

Open AccessArticle

Surface Characteristics of Machined Polystyrene with 3D Printed Thermoplastic Tool

by Kamalpreet Sandhu, Gurminder Singh, Sunpreet Singh, Raman Kumar, Chander Prakash, Seeram Ramakrishna, Grzegorz Królczyk and Catalin I. Pruncu

Materials 2020, 13(12), 2729; https://doi.org/10.3390/ma13122729 - 16 Jun 2020

Cited by 57 | Viewed by 3361

Abstract

An effort is made in this work to appraise the surface characteristics of machined expandable polystyrene (EPS) with a novel 3D printed thermoplastic acrylonitrile-butadiene-styrene (ABS) tool. Linear grooves on EPS were made on a vertical milling machine that was modified to conduct experiments in the laboratory. The tests were designed as per the Taguchi L9 based factorial design of experimentation while varying process parameters such as depth of cut, spindle speed, and feed rate. The machining responses dimensional accuracy and surface roughness of the machined grooves were studied. Furthermore, the surface topography of the machined specimens was considered to investigate the mechanism of material removal in response to the processing conditions. Moreover, mathematical models developed for the prediction of the output responses showed a significant correlation with the experimental results. The results of the statistical study indicate that the surface roughness is influenced by the spindle speed and dimensional accuracy by the depth-of-cut. Overall, the findings of the experimental work advocated the feasibility of 3D printed thermoplastic tools for machining soft polymeric materials. It can become a useful alternative for mass and batch production. Full article

(This article belongs to the Special Issue Hybrid Additive Manufacturing and Machining Machine-Tools and Processes)

► Show Figures

Figure 1

15 pages, 6912 KiB

Open AccessArticle

Analysis of the Machining Process of Titanium Ti6Al-4V Parts Manufactured by Wire Arc Additive Manufacturing (WAAM)

by Fernando Veiga, Alain Gil Del Val, Alfredo Suárez and Unai Alonso

Materials 2020, 13(3), 766; https://doi.org/10.3390/ma13030766 - 07 Feb 2020

Cited by 48 | Viewed by 5097

Abstract

In the current days, the new range of machine tools allows the production of titanium alloy parts for the aeronautical sector through additive technologies. The quality of the materials produced is being studied extensively by the research community. This new manufacturing paradigm also opens important challenges such as the definition and analysis of the optimal strategies for finishing-oriented machining in this type of part. Researchers in both materials and manufacturing processes are making numerous advances in this field. This article discusses the analysis of the production and subsequent machining in the quality of TI6Al4V produced by Wire Arc Additive Manufacturing (WAAM), more specifically Plasma Arc Welding (PAW). The promising results observed make it a viable alternative to traditional manufacturing methods. Full article

(This article belongs to the Special Issue Hybrid Additive Manufacturing and Machining Machine-Tools and Processes)

► Show Figures

Figure 1

17 pages, 12031 KiB

Open AccessArticle

Areal Surface Roughness Optimization of Maraging Steel Parts Produced by Hybrid Additive Manufacturing

by Philipp Wüst, André Edelmann and Ralf Hellmann

Materials 2020, 13(2), 418; https://doi.org/10.3390/ma13020418 - 16 Jan 2020

Cited by 40 | Viewed by 4876

Abstract

We report on an experimental study and statistical optimization of the surface roughness using design of experiments and the Taguchi method for parts made of 1.2709 maraging steel. We employ a hybrid additive manufacturing approach that combines additive manufacturing by selective laser melting with subtractive manufacturing using milling in an automated process within a single machine. Input parameters such as laser power, scan speed, and hatching distance have been varied in order to improve surface quality of unmachined surfaces. Cutting speed, feed per tooth, and radial depth of cut have been varied to optimize surface roughness of the milled surfaces. The surfaces of the samples were characterized using 3D profilometry. Scan speed was determined as the most important parameter for non-machined surfaces; radial depth of cut was found to be the most significant parameter for milled surfaces. Areal surface roughness

S_{a}

could be reduced by up to 40% for unmachined samples and by 23% for milled samples as compared to the prior state of the art. Full article

(This article belongs to the Special Issue Hybrid Additive Manufacturing and Machining Machine-Tools and Processes)

► Show Figures

Graphical abstract

14 pages, 3638 KiB

Open AccessArticle

A Study on Optimal Machining Conditions and Energy Efficiency in Plasma Assisted Machining of Ti-6Al-4V

by Young-Hun Lee and Choon-Man Lee

Materials 2019, 12(16), 2590; https://doi.org/10.3390/ma12162590 - 14 Aug 2019

Cited by 13 | Viewed by 2882

Abstract

This research objective was to determine the significant parameters for effective plasma assisted machining (PAM) of Ti-6Al-4V and to derive optimal processing conditions. PAM parameters such as feed rate, spindle speed, and depth of cut have significant effects on its machining characteristic. In this study, the design of experiments (DOE) was used to select optimal machining conditions for PAM. The signal-to-noise (S/N) ratio was analyzed using the Taguchi method and the contributions of the factors were determined using analysis of variance (ANOVA). Finally, the optimal PAM machining conditions were selected using response optimization. In addition, the energy efficiency of conventional machining (CM) and the PAM were compared. The energy efficiency was analyzed by specific cutting energy. The cutting force and surface roughness of PAM decreased by 60.2% and 70.5%, respectively, in optimal PAM machining conditions. Full article

(This article belongs to the Special Issue Hybrid Additive Manufacturing and Machining Machine-Tools and Processes)

► Show Figures

Figure 1

24 pages, 14039 KiB

Open AccessArticle

Material Characterization of AISI 316L Flexure Pivot Bearings Fabricated by Additive Manufacturing

by Mirko Riede, Matthias Knoll, Christoph Wilsnack, Samira Gruber, Alba Alegre Cubillo, Christian Melzer, Ana Brandão, Laurent Pambaguian, André Seidel, Elena Lopez, Frank Brueckner and Christoph Leyens

Materials 2019, 12(15), 2426; https://doi.org/10.3390/ma12152426 - 30 Jul 2019

Cited by 11 | Viewed by 4232

Abstract

Recently, additive manufacturing (AM) by laser metal deposition (LMD) has become a key technology for fabricating highly complex parts without any support structures. Compared to the well-known powder bed fusion process, LMD enhances manufacturing possibilities to overcome AM-specific challenges such as process inherent porosity, minor build rates, and limited part size. Moreover, the advantages aforementioned combined with conventional machining enable novel manufacturing approaches in various fields of applications. Within this contribution, the additive manufacturing of filigree flexure pivots using 316L-Si by means of LMD with powder is presented. Frictionless flexure pivot bearings are used in space mechanisms that require high reliability, accuracy, and technical cleanliness. As a contribution to part qualification, the manufacturing process, powder material, and fabricated specimens were investigated in a comprehensive manner. Due to its major impact on the process, the chemical powder composition was characterized in detail by energy dispersive X-ray spectroscopy (EDX) and inductively coupled plasma optical emission spectrometry (ICP-OES). Moreover, a profound characterization of the powder morphology and flowability was carried out using scanning electron microscopy (SEM) and novel rheological investigation techniques. Furthermore, quantitative image analysis, mechanical testing, laser scanning microscopy, and 3D shape measurement of manufactured specimens were conducted. As a result, the gained knowledge was applied for the AM-specific redesign of the flexure pivot. Finally, a qualified flexure pivot has been manufactured in a hybrid manner to subsequently ensure its long-term durability in a lifetime test bench. Full article

(This article belongs to the Special Issue Hybrid Additive Manufacturing and Machining Machine-Tools and Processes)

► Show Figures

Figure 1

14 pages, 11146 KiB

Open AccessArticle

Analysis of the Machining Process of Inconel 718 Parts Manufactured by Laser Metal Deposition

by Txomin Ostra, Unai Alonso, Fernando Veiga, Mikel Ortiz, Pedro Ramiro and Amaia Alberdi

Materials 2019, 12(13), 2159; https://doi.org/10.3390/ma12132159 - 05 Jul 2019

Cited by 30 | Viewed by 3832

Abstract

Laser metal deposition (LMD) is an additive manufacturing process that allows the manufacturing of near-net-shape products. This could mean significant savings in terms of materials and costs in the manufacturing of high-performance components for the aeronautical industry. In this work, an analysis of how the LMD processing of alloy 718 affects the final machining has been carried out. For this purpose, a comparative study has been done by means of the monitoring of the end milling process of a part manufactured by LMD and a rough-milled part from forged material. Differences between process outputs such as chip morphology and cutting forces were studied. Material characteristics such as microstructure, hardness and mechanical properties were also analyzed. Full article

(This article belongs to the Special Issue Hybrid Additive Manufacturing and Machining Machine-Tools and Processes)

► Show Figures

Figure 1

20 pages, 20725 KiB

Open AccessArticle

A Hybrid Process Integrating Reverse Engineering, Pre-Repair Processing, Additive Manufacturing, and Material Testing for Component Remanufacturing

by Xinchang Zhang, Wenyuan Cui, Wei Li and Frank Liou

Materials 2019, 12(12), 1961; https://doi.org/10.3390/ma12121961 - 18 Jun 2019

Cited by 26 | Viewed by 4413

Abstract

Metallic components can gain defects such as dents, cracks, wear, heat checks, deformation, etc., that need to be repaired before reinserting into service for extending the lifespan of these parts. In this study, a hybrid process was developed to integrate reverse engineering, pre-repair processing, additive manufacturing, and material testing for the purpose of part remanufacturing. Worn components with varied defects were scanned using a 3D scanner to recreate the three-dimensional models. Pre-repair processing methods which include pre-repair machining and heat-treatment were introduced. Strategies for pre-repair machining of defects including surface impact damage, surface superficial damage and cracking were presented. Pre-repair heat-treatment procedure for H13 tool steel which was widely used in die/mold application was introduced. Repair volume reconstruction methodology was developed to regain the missing geometry on worn parts. The repair volume provides a geometry that should be restored in the additive manufacturing process. A damaged component was repaired using the directed energy deposition process to rebuild the worn geometry. The repaired part was inspected in microstructure and mechanical aspects to evaluate the repair. The hybrid process solved key issues associated with repair, providing a solution for automated metallic component remanufacturing. Full article

(This article belongs to the Special Issue Hybrid Additive Manufacturing and Machining Machine-Tools and Processes)

► Show Figures

Figure 1

11 pages, 6384 KiB

Open AccessArticle

A Study on the Dimension Accuracy on the Inner Structure of the 3D Printed Parts Caused by the Scanning Strategy

by Jitai Han, Meiping Wu and Yanan Ge

Materials 2019, 12(8), 1333; https://doi.org/10.3390/ma12081333 - 24 Apr 2019

Cited by 6 | Viewed by 2593

Abstract

Selective laser melting (SLM) has been used in many fields recently, especially in the aerospace field. Many studies have been done on mechanical properties of the printed parts, but the dimension accuracy of the inner structure received little attention during these years. In this work, the dimension accuracy of the inner structure was measured and compared using different scanning strategies. Compared with the measured data, a new scanning strategy was used and finds that the dimension accuracy was better than the previous one that used a two-scanning strategy. To explain this phenomenon, finite element analysis (FEA) was used to show the temperature distribution after a 0.1 s cooling using two different scanning strategies, which caused the dimensional deviation in printing. Full article

(This article belongs to the Special Issue Hybrid Additive Manufacturing and Machining Machine-Tools and Processes)

► Show Figures

Figure 1

10 pages, 2420 KiB

Open AccessArticle

Microstructural Tuning of a Laser-Cladding Layer by Means of a Mix of Commercial Inconel 625 and AISI H13 Powders

by Maider Muro, Josu Leunda, Garikoitz Artola and Carlos Soriano

Materials 2019, 12(3), 544; https://doi.org/10.3390/ma12030544 - 12 Feb 2019

Cited by 7 | Viewed by 3685

Abstract

The aim of this work is to evaluate the microstructural evolutions developed by mixing a corrosion-resistant and high-performance material with a high-hardness material in a coating obtained by laser-cladding technology. In this paper, five different mixtures of Inconel 625 alloy and AISI H13 steel powders have been deposited on a plate of 42CrMo4 steel using a 2.2 kW diode pumped Nd:YAG laser. The effect of adding tool steel to a Ni-based superalloy has been analyzed by the characterization of each cladded sample using optical microscopy and scanning electron microscopy (SEM). The precipitates observed in the samples have been analyzed by energy dispersive X-ray spectroscopy (EDS X-ray). SEM micrographs and EDS analysis indicate the existence of Laves phase. It has been observed that the presence of these precipitates is stabilized in a certain range of AISI H13 addition. Full article

(This article belongs to the Special Issue Hybrid Additive Manufacturing and Machining Machine-Tools and Processes)

► Show Figures

Figure 1

13 pages, 9844 KiB

Open AccessArticle

Development of an Intra-Layer Adaptive Toolpath Generation Control Procedure in the Laser Metal Wire Deposition Process

by Iker Garmendia, Joseba Pujana, Aitzol Lamikiz, Jon Flores and Mikel Madarieta

Materials 2019, 12(3), 352; https://doi.org/10.3390/ma12030352 - 23 Jan 2019

Cited by 26 | Viewed by 3548

Abstract

Recently developed concentric laser metal wire deposition (LMWD) heads allow metal addition processes which are independent of the deposition direction, thus enabling complex paths to be generated. The sensitivity of the process to height deviations has experimentally been observed to be greater with this type of head than with powder ones, therefore requiring more precise and local process control algorithms to be implemented. This work developed a methodology for measuring the part, layer by layer, using a 3D scanner based on structured laser light. Height corrections were applied to the mean and intra-layer height deviations by recalculating the deposition trajectories of the next layer to be deposited. Local height deviations were adjusted by varying the scanning speed, thus increasing the feed rate in the lower areas and decreasing it in the higher ones. Defects generated in the purpose, with height differences within the layer, were successfully corrected. A flat layer was re-established through the application of the control strategy. The internal integrity of the parts due to the scanning speed variation was analyzed, resulting in fully dense parts. The structured light measurement and height correction systems are found to be an affordable and time-efficient solution that can be integrated into an LMWD environment, thereby improving the process robustness. Full article

(This article belongs to the Special Issue Hybrid Additive Manufacturing and Machining Machine-Tools and Processes)

► Show Figures

Figure 1

11 pages, 5728 KiB

Open AccessArticle

Analysis of Melt Pool Characteristics and Process Parameters Using a Coaxial Monitoring System during Directed Energy Deposition in Additive Manufacturing

by Christian Kledwig, Holger Perfahl, Martin Reisacher, Frank Brückner, Jens Bliedtner and Christoph Leyens

Materials 2019, 12(2), 308; https://doi.org/10.3390/ma12020308 - 19 Jan 2019

Cited by 43 | Viewed by 6154

Abstract

The growing number of commercially available machines for laser deposition welding show the growing acceptance and importance of this technology for industrial applications. Their increasing usage in research and production requires process stability and user-friendly handling. A commercially available DMG MORI LT 65 3D hybrid machine used in combination with a CCD-based coaxial temperature measurement system was utilized in this work to investigate what information relating to the intensity distribution of melt pool surfaces could be appropriate to draw conclusions about process conditions. In this study it is shown how the minimal required specific energy for a stable process can be determined, and it is indicated that the evolution of a plasma plume depends on thermal energy within the base material. An estimated melt pool area—calculated by the number of pixels (NOP) with intensities larger than a fixed, predefined threshold—builds the main measure in analysing images from the process camera. The melt pool area and its temporal variance can also serve as an indicator for an increased working distance. Full article

(This article belongs to the Special Issue Hybrid Additive Manufacturing and Machining Machine-Tools and Processes)

► Show Figures

Graphical abstract

Review

Jump to: Research

31 pages, 6618 KiB

Open AccessReview

Laser Cutting: A Review on the Influence of Assist Gas

by Antonio Riveiro, Félix Quintero, Mohamed Boutinguiza, Jesús Del Val, Rafael Comesaña, Fernando Lusquiños and Juan Pou

Materials 2019, 12(1), 157; https://doi.org/10.3390/ma12010157 - 06 Jan 2019

Cited by 60 | Viewed by 12545

Abstract

Assist gas plays a central role in laser fusion cutting. In this work, the aerodynamic interactions between the assist gas and the workpiece are reviewed. An insight into those phenomena that hinder the cutting quality and performance is provided. These phenomena include shock waves, choking, boundary layer separation, etc. The most relevant and promising attempts to overcome these common problems related to the gas dynamics are surveyed. The review of the current scientific literature has revealed some gaps in the current knowledge of the role of the assist gas dynamics in laser cutting. The assist gas interactions have been investigated only under static conditions; and the dynamic interaction with the molten material on the cutting front has not been addressed. New nozzle designs with improved efficiency of molten material removal are required to improve cut quality; and cutting speed in current industrial laser cutting machines; especially in those assisted by new high-brightness laser sources. Full article

(This article belongs to the Special Issue Hybrid Additive Manufacturing and Machining Machine-Tools and Processes)

► Show Figures

Figure 1

27 pages, 5401 KiB

Open AccessReview

Latest Developments in Industrial Hybrid Machine Tools that Combine Additive and Subtractive Operations

by Magdalena Cortina, Jon Iñaki Arrizubieta, Jose Exequiel Ruiz, Eneko Ukar and Aitzol Lamikiz

Materials 2018, 11(12), 2583; https://doi.org/10.3390/ma11122583 - 18 Dec 2018

Cited by 73 | Viewed by 8153

Abstract

Hybrid machine tools combining additive and subtractive processes have arisen as a solution to increasing manufacture requirements, boosting the potentials of both technologies, while compensating and minimizing their limitations. Nevertheless, the idea of hybrid machines is relatively new and there is a notable lack of knowledge about the implications arisen from their in-practice use. Therefore, the main goal of the present paper is to fill the existing gap, giving an insight into the current advancements and pending tasks of hybrid machines both from an academic and industrial perspective. To that end, the technical-economical potentials and challenges emerging from their use are identified and critically discussed. In addition, the current situation and future perspectives of hybrid machines from the point of view of process planning, monitoring, and inspection are analyzed. On the one hand, it is found that hybrid machines enable a more efficient use of the resources available, as well as the production of previously unattainable complex parts. On the other hand, it is concluded that there are still some technological challenges derived from the interaction of additive and subtractive processes to be overcome (e.g., process planning, decision planning, use of cutting fluids, and need for a post-processing) before a full implantation of hybrid machines is fulfilled. Full article

(This article belongs to the Special Issue Hybrid Additive Manufacturing and Machining Machine-Tools and Processes)

► Show Figures

Figure 1

Journal Menu

Journal Browser

Hybrid Additive Manufacturing and Machining Machine-Tools and Processes

Share This Special Issue

Special Issue Editors

Special Issue Information

Keywords

Related Special Issue

Published Papers (13 papers)

Research

Review

Further Information

Guidelines

MDPI Initiatives

Follow MDPI