Metal Additive Manufacturing: Enhancing Performance and Surface Finishing

A special issue of Applied Sciences (ISSN 2076-3417). This special issue belongs to the section "Additive Manufacturing Technologies".

Deadline for manuscript submissions: closed (31 December 2022) | Viewed by 19254

Special Issue Editors

Department of Engineering, Università degli studi Niccolò Cusano, 00166 Rome, Italy
Interests: materials and technology for surface manufacturing; laser processing; metal foams; material characterization
Special Issues, Collections and Topics in MDPI journals
Department of Engineering, Università degli studi Niccolò Cusano, 00166 Rome, Italy
Interests: laser technology for manufacturing; additive manufacturing; soft computing for process optimization

Special Issue Information

Dear Colleagues,

Metal additive manufacturing (MAM) technologies are attracting a growing amount of interest thanks to the wide range of applications in which they can be applied. In fact, they offer the possibility of an extremely high degree of design customization, as well as the opportunity to use various raw materials with savings in terms of use, costs, and time of design and production if compared to traditional processes. However, such an overwhelming expansion has led to the lack of clear and well-defined guidelines in terms of process parameters and resulting properties. Moreover, the surface quality that can be achieved for the as-built components is still poor and is considered one of the main limiting aspects of such technologies. This inevitably leads to an increase in critical issues that, in order to be overcome, introduce additional costs and lengthen the production times.

This Special Issue aims to collect scientific contributions on new technologies, strategies, manufacturing approaches, and materials for the additive manufacturing of metals. Scientific contributions can be focused on process optimization for improved mechanical properties and surface finish, new material development for high-performance applications, and surface treatments. Furthermore, characterization methods and computational approaches for modeling the process and material properties (such as numerical simulations, mathematical modeling, optimization, control, etc.) and contributions featuring an environmental impact analysis (LCA), are of interest.

Prof. Stefano Guarino
Dr. Gennaro Salvatore Ponticelli
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. Applied Sciences 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 2400 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

  • additive manufacturing
  • advanced materials
  • characterization
  • finishing
  • life cycle assessment
  • metals
  • numerical and mathematical modeling
  • surface treatment

Published Papers (6 papers)

Order results
Result details
Select all
Export citation of selected articles as:

Research

Jump to: Review

16 pages, 16669 KiB  
Article
Part Tailoring in Metal-Additive Manufacturing: A Step towards Functionally Graded Customized Stainless-Steel Components Using Laser Powder Bed Fusion
by Ahmed Elkaseer, Amal Charles, Stella Schneider and Steffen G. Scholz
Appl. Sci. 2022, 12(12), 6193; https://0-doi-org.brum.beds.ac.uk/10.3390/app12126193 - 17 Jun 2022
Viewed by 1478
Abstract
The aim of this project is to demonstrate a proof of concept by using Additive Manufacturing (AM) technology in order to demonstrate its viability for the production of tailor-made components with regions of varying (higher and lower) hardness and surface roughness within a [...] Read more.
The aim of this project is to demonstrate a proof of concept by using Additive Manufacturing (AM) technology in order to demonstrate its viability for the production of tailor-made components with regions of varying (higher and lower) hardness and surface roughness within a single part. In order to do this, first a test piece is designed and printed following a full factorial design of the experiment with eight runs with varying process parameters set within different regions of one part. The structure is printed several times with the laser-powder-bed-fusion-based metal-additive-manufacturing system “Sodick LPM 325” using AISI 420 in order to test and validate the change in the achievable mechanical property and surface roughness. The above-mentioned quality marks are characterized using a tactile profilometer, Rockwell test and part density, and the results are statistically analyzed using MATLAB. The results show that the linear energy density plays a significant role in controlling the surface roughness of the top surface of the components while the hardness on the top surface is unaffected. On the side surfaces, it is known that the layer thickness plays a significant role on the surface roughness as well as hardness. Looking at the results obtained, it is seen that the variation in the obtained side surface roughness is not significant to changes in the Linear Energy Density (LED) as the layer thickness was kept constant, with only slight reductions in hardness seen. The annealing process resulted in a significant reduction in hardness. This work has shown that through the careful tailoring of processing conditions, multi-functionality within one part can be integrated and has created promising avenues for further research into achieving fully functionally graded structures. Full article
Show Figures

Figure 1

17 pages, 6008 KiB  
Article
Fabrication of a Stainless-Steel Pump Impeller by Integrated 3D Sand Printing and Casting: Mechanical Characterization and Performance Study in a Chemical Plant
by Felix Hernández and Alex Fragoso
Appl. Sci. 2022, 12(7), 3539; https://0-doi-org.brum.beds.ac.uk/10.3390/app12073539 - 30 Mar 2022
Cited by 4 | Viewed by 3925
Abstract
The emergence of additive manufacturing is renovating the landscape of available production technologies. In this paper, we describe the fabrication of a closed vane pump impeller (ϕ 206 mm, height 68 mm, weight 4 kg) by binder jetting 3D printing of a sand [...] Read more.
The emergence of additive manufacturing is renovating the landscape of available production technologies. In this paper, we describe the fabrication of a closed vane pump impeller (ϕ 206 mm, height 68 mm, weight 4 kg) by binder jetting 3D printing of a sand mould followed by casting using stainless steel 316 to create an identical copy of a part in service in a chemical plant in Tarragona, Spain. The original part was reverse engineered and used to create a sand mould by binder jetting 3D printing on which new impellers were fabricated by casting. Metallographic studies showed an austenitic matrix with 6.3% of ferritic phase and 40 μm × 8 μm ferrite grains without precipitated carbides. The impeller was put into operation in a centrifugal pump at a polyol/polyglycol plant belonging to Dow Chemical Ibérica SL from October 2020 to April 2021. Process variables related to the pump behaviour were compared with the same variables obtained in previous cycles with the original impeller for three different product viscosities (30, 180, and 500 cSt). At 500 cSt, the average current consumption was 9.34 A as compared with the 9.41 A measured with the original impeller. Similarly, the pump pressure remained essentially constant during process operation with both impellers (3.97 bar with the new impeller vs. 3.99 bar with the old). Other monitored parameters (product flow, tank level) were similar in both cases, validating the fabrication strategy from an operational point of view. This work further demonstrated that the implementation of additive manufacturing technologies in chemical process engineering is a useful solution to fabricate spare parts that are difficult to replicate with other technologies, providing consequent economic benefits. Full article
Show Figures

Graphical abstract

19 pages, 19021 KiB  
Article
Investigation and Simulation of the Surface Contact Characteristics of Sinter-Joined Binder Jetting Components
by Alexander Rütjes, Lukas Stahl, Michael Müller and Frank Petzoldt
Appl. Sci. 2022, 12(7), 3478; https://0-doi-org.brum.beds.ac.uk/10.3390/app12073478 - 29 Mar 2022
Cited by 4 | Viewed by 2813
Abstract
Binder jetting holds great potential for revolutionizing conventional production processes for high-performance components. However, current applications face significant challenges regarding the depowdering and cleaning of complex internal geometries. A novel approach to these challenges is splitting the desired component into smaller, easy-to-clean parts [...] Read more.
Binder jetting holds great potential for revolutionizing conventional production processes for high-performance components. However, current applications face significant challenges regarding the depowdering and cleaning of complex internal geometries. A novel approach to these challenges is splitting the desired component into smaller, easy-to-clean parts and using sinter bonding to achieve the desired shape. This greatly reduces manual cleaning and preparation time during the production since sintering is required in any case. The sinter joint is currently significantly weaker than the rest of the part and may pose a risk of failure. This study focuses on the effects of different parameters that influence the joint strength and the contact surface between two parts. With different experimental setups, a variety of influences is identified and quantified: depowdering air pressure, component orientation in the build box, initial contact pressure between the green parts, and macroscopic component deformation. The experimental results are supported by a modified Boussinesq contact model. Combining experiments and simulations, it was found that the relative contact between two green parts varies between 5 and 26%, depending on the parameter set used. In this study, the authors introduce the idea of two-part manufacturing in metal binder jetting and subsequent joining of the components in the sintering process. Full article
Show Figures

Graphical abstract

15 pages, 22707 KiB  
Article
Wire Arc Additive and High-Temperature Subtractive Manufacturing of Ti-6Al-4V
by Ryotaro Miyake, Hiroyuki Sasahara, Atsushi Suzuki and Seigo Ouchi
Appl. Sci. 2021, 11(20), 9521; https://0-doi-org.brum.beds.ac.uk/10.3390/app11209521 - 13 Oct 2021
Cited by 4 | Viewed by 1538
Abstract
We investigated the fabrication and finishing of wall-profile machining by wire and arc additive manufacturing (WAAM) employing plasma welding with Ti-6Al-4V wire. We fabricated and integrated a local shield and a cover for the area below the local shield to achieve higher shielding [...] Read more.
We investigated the fabrication and finishing of wall-profile machining by wire and arc additive manufacturing (WAAM) employing plasma welding with Ti-6Al-4V wire. We fabricated and integrated a local shield and a cover for the area below the local shield to achieve higher shielding ability. The tensile strength of the fabricated object met the forging standard for Ti-6Al-4V, but elongation was about 7%. We also focused on the possibility of reducing the cutting force and increasing the efficiency of the finishing process by cutting workpieces softened by high temperature immediately after the deposition process. We investigated the cutting force and tool wear of the fabricated objects heated to 300 °C using ceramics tools. Results showed that although the cutting force was reduced at high temperature, the wear rate of the tools was high, and the increase in cutting force due to wear was significant. Full article
Show Figures

Figure 1

18 pages, 7531 KiB  
Article
Re-Engineering of an Impeller for Submersible Electric Pump to Be Produced by Selective Laser Melting
by Gennaro Salvatore Ponticelli, Flaviana Tagliaferri, Simone Venettacci, Matthias Horn, Oliviero Giannini and Stefano Guarino
Appl. Sci. 2021, 11(16), 7375; https://0-doi-org.brum.beds.ac.uk/10.3390/app11167375 - 11 Aug 2021
Cited by 10 | Viewed by 3265
Abstract
The subject of the present study is the reproduction of a submersible electric pump impeller through reverse engineering and additive manufacturing. All of the phases commonly envisaged in the reproduction of an existing piece were carried out. The aim of the study is [...] Read more.
The subject of the present study is the reproduction of a submersible electric pump impeller through reverse engineering and additive manufacturing. All of the phases commonly envisaged in the reproduction of an existing piece were carried out. The aim of the study is to show how the chosen pump component can be effectively re-engineered and produced with the selective laser melting technique, obtaining a final product that is comparable if not even better than the starting one. To achieve this goal, the original piece was redesigned and a new model was created and analyzed. The whole process has been split into three main phases: (i) realization of the three-dimensional model from an existing piece using reverse engineering techniques; (ii) finite element analysis for the optimization of the use of the material; and (iii) 3D printing of a concept model in polyethylene terephthalate by using the fused deposition modeling technology and of the functional model in AISI 316 stainless steel with selective laser melting technology. Full article
Show Figures

Figure 1

Review

Jump to: Research

34 pages, 19556 KiB  
Review
Design and Fabrication Technology of Metal Mirrors Based on Additive Manufacturing: A Review
by Kai Zhang, Hemeng Qu, Haijun Guan, Jizhen Zhang, Xin Zhang, Xiaolin Xie, Lei Yan and Chao Wang
Appl. Sci. 2021, 11(22), 10630; https://0-doi-org.brum.beds.ac.uk/10.3390/app112210630 - 11 Nov 2021
Cited by 21 | Viewed by 4918
Abstract
In recent years, much progress has been made on the development of metal mirrors based on additive manufacturing (AM). The sandwich mirror is well known for its excellent mechanical properties and challenging machining. Now, AM can be used to fabricate this complex structure [...] Read more.
In recent years, much progress has been made on the development of metal mirrors based on additive manufacturing (AM). The sandwich mirror is well known for its excellent mechanical properties and challenging machining. Now, AM can be used to fabricate this complex structure and reduce the processing time and cost. In addition, with the aid of some new design methods for additive manufacturing, such as lattice, topology optimization (TO), and Voronoi, the freedom of mirror structure design is enormously improved. The common materials of mirrors include ceramics (SiC), glasses (glass ceramics, fused silica), and metals (aluminum, beryllium). Among them, the AM technology of metals is the most mature and widely used. Researchers have recently extensively developed the new-generation metal mirror to improve performance and lightweight rate. This review focuses on the following topics: (1) AM technologies and powder materials for metal mirrors, (2) recent advances in optomechanical design methods for AM metal mirrors, (3) challenges faced by AM metal mirrors in fabricating, and (4) future trends in AM metal mirrors. Full article
Show Figures

Figure 1

Back to TopTop