Application Of Additive Manufacturing Technology Research Articles

Additive Manufacturing of Rare Earth Permanent Magnetic Materials: Research Status and Prospects

With the rapid development of intelligent manufacturing, modern components are accelerating toward being light weight, miniaturized, and complex, which provides a broad space for the application of rare earth permanent magnet materials. As an emerging near-net-shape manufacturing process, additive manufacturing (AM) has a short process flow and significantly reduces material loss and energy consumption, which brings new possibilities and impetus to the development of rare earth permanent magnetic materials. Here, the applications of AM technology in the field of rare earth permanent magnets in recent years are reviewed and prospected, including laser powder bed fusion (LPBF), fused deposition modeling (FDM), and binder jetting (BJ) techniques. Research has found that the magnetic properties of AM Nd-Fe-B magnets can reach or even exceed the traditional bonded magnets. In addition, in situ magnetic field alignment, in situ grain boundary infiltration, and post-processing methods are effective in enhancing the magnetic properties of AM magnets. These results have laid a good foundation for the development of AM rare earth permanent magnets.

Improving the fatigue property of 316L stainless steel through direct energy deposition technology

In this study, to improve the fatigue strength of coarse grain 316L stainless steel, the hard 17-4ph martensitic stainless steel was deposited on the surface of hot rolled 316L based on direct energy deposition (DED) additive manufacturing technology. The 17-4ph deposition and 316L substrate are well connected without any cracking phenomenon which lays the foundation of good mechanical properties. The 17-4ph deposition presents a gradient structure, its fraction of body centered cubic (BCC) phase gradually increases from 0 vol% of substrate to 99.3 vol% of top surface, and its grain size gradually decreases from 53.2 μm near the substrate to 5.1 μm of the top surface, leading to the hardness of deposition gradually increases from 187 Hv to 436 Hv. The fatigue property of 17-4ph coated 316L is significantly improved. Specifically, the fatigue strength in high cycle fatigue (HCF) regime (at the fatigue life of 2 × 106 cycles) is 64 % higher than coarse-grained 316L, while the increment in low cycle fatigue (LCF) regime (at the fatigue life of 104 cycles) is up to 100 %. The improvement in LCF regime of 17-4ph coated 316L is higher than that of HCF regime, which is exactly opposite to the improvement in HCF and LCF regime of samples fabricated by traditional surface strengthening processes. Based on advanced characterization techniques, the potential strengthening mechanism in 17-4ph coated 316L was studied. It is expected that this study can provide reference for the application of additive manufacturing technology in the field of surface strengthening.

Microstructure and mechanical properties of Cu-Cr-Zr alloy prepared by electron beam additive manufacturing and laser-MIG hybrid welding

Cu-Cr-Zr alloys are widely used as medium-strength and high-conductivity copper alloys in aerospace, transportation and electronic information fields. The application of additive manufacturing technology is expected to realize the preparation of Cu-Cr-Zr alloy parts with complex structure and superior property. However, the commonly used laser additive manufacturing technology is not applicable to the preparation of copper alloys due to its intrinsic high reflection to laser. In this study, we adopted two technologies, i.e., electron beam additive manufacturing (EBAM) and laser-metal inert gas hybrid welding (laser-MIG), for the preparation of Cu-Cr-Zr alloys. Finite element simulation was employed to simulate the temperature field and residual stress field of the material during solidification. The microstructure, relative density, microhardness, tensile properties and electrical conductivity of the as-fabricated samples were characterized. The results showed that samples with better moldability were obtained by both methods at a line energy density of 600 J/mm. In the top area, both methods exhibit medium-sized equiaxed grains with more precipitated phases, showing the best comprehensive properties. The EBAM method demonstrates superior formability, better relative density and electrical conductivity due to more stable temperature field changes. On the other hand, the laser-MIG method obtains finer grains and higher mechanical properties because of a faster cooling rate, but leads to a decrease in relative density and electrical conductivity. This study presents new experimental data for Cu-Cr-Zr alloys prepared by EBAM and laser-MIG methods, contributing to extend the application of additive manufacturing in the preparation of Cu alloys.

High fatigue resistance in a titanium alloy via near-void-free 3D printing.

The advantage of 3D printing-that is, additive manufacturing (AM) of structural materials-has been severely compromised by their disappointing fatigue properties1,2. Commonly, poor fatigue properties appear to result from the presence of microvoids induced by current printing process procedures3,4. Accordingly, the question that we pose is whether the elimination of such microvoids can provide a feasible solution for marked enhancement of the fatigue resistance of void-free AM (Net-AM) alloys. Here we successfully rebuild an approximate void-free AM microstructure in Ti-6Al-4V titanium alloy by development of a Net-AM processing technique through an understanding of the asynchronism of phase transformation and grain growth. We identify the fatigue resistance of such AM microstructures and show that they lead to a high fatigue limit of around 1 GPa, exceeding the fatigue resistance of all AM and forged titanium alloys as well as that of other metallic materials. We confirm the high fatigue resistance of Net-AM microstructures and the potential advantages of AM processing in the production of structural components with maximum fatigue strength, which is beneficial for further application of AM technologies in engineering fields.

Numerical investigation on effect of different projectile nose shapes on ballistic impact of additively manufactured AlSi10Mg alloy

In the last few years, due to the superior mechanical qualities of Additive Manufacturing (AM) AlSi10Mg alloy to those of traditional casting process AlSi10Mg alloys, the application of AM technology has significantly increased. The ballistic impact research has a wide range of uses, notably in the mining, construction, spacecraft and defence sectors. This work focuses on analyzing the behavior of different projectile nose shapes on the AlSi10Mg alloy fabricated by AM. There are several projectile nose forms to consider, including blunt, hemispherical, conical, and ogive shapes. The impact of various projectile shapes on the ballistic limit of the additively created AlSi10Mg alloy is carefully examined in this study. All numerical simulations were carried out using LS-DYNA software, and the Johnson-Cook material and damage model were considered to assess the ballistic resistance behavior. The ballistic limit for various projectile shapes is computed using the Jonas-Lambert model, which describes the connection between residual velocity and starting projectile velocity. The results showed that, the ogive-shaped Projectile offers the highest ballistic limit, and the blunt projectile shows the lowest ballistic limit for a 5 mm thin target plate. The ballistic impact phenomenon showed plugging failure for the blunt nose projectile, the formation of plug and small fragments were observed in the case of hemispherical nose projectile, fragmenting failure is observed with radial necking in the case of conical nose projectile and petals are formed at the impacted zone in ogive nose shape projectile. Moreover, the ballistic limit of AM AlSi10Mg alloy was slightly higher compared to the ballistic limit of the die-cast AlSi10Mg alloy for the 7.62 mm AP bullet (core). Therefore, AM AlSi10Mg alloy may have equal or good ballistic properties compared to die-cast AlSi10Mg alloy.

Application of Additive Manufacturing Technology for Chair Parts Connections

Additive manufacturing (AM) is a potential technology to be applied for replacing wood joints in the furniture industry. Overall, 3D-printed connectors have a lot of advantages in chair construction: the possibility of improving the design by using colored materials and new concepts with no limits of shape and size, avoiding the use of synthetic materials such as adhesives and finishing materials. The present research shows the results of the research conducted on 3D-printed connectors for a chair leg-stretchers joint. Larch (Larix decidua Mill.) wood was used for chair components and selective laser sintering (SLS) technology was employed for the 3D-printing connector designed to assemble the chair elements. Diagonal tensile and compression tests were performed on the L-type joints with 3D-printed connectors and the bending moments were determined and compared to the results obtained after testing the leg-stretchers mortise–tenon joints made of larch wood, taken as a reference. Micrograph investigation was finally performed on the broken areas of the 3D-printed connectors as a result of mechanical testing failures. The results show that the SLS printing technology applied to build the connector does not ensure enough strength to the assembly, and changes in printing parameters are needed for further research, in terms of laser power and scan speed.

Predicting Properties of Fused Filament Fabrication Parts through Sensors and Machine Learning

Fused filament fabrication (FFF), colloquially known as 3D-printing, has gradually expanded from the laboratory to the industrial and household realms due to its suitability for producing highly customized products with complex geometries. However, it is difficult to evaluate the mechanical performance of samples produced by this method of additive manufacturing (AM) due to the high number of combinations of printing parameters, which have been shown to significantly impact the final structural integrity of the part. This implies that using experimental data attained through destructive testing is not always viable. In this study, predictive models based on the rapid prediction of the required extrusion force and mechanical properties of printed parts are proposed, selecting a subset of the most representative printing parameters during the printing process as the domain of interest. Data obtained from the in-line sensor-equipped 3D printers were used to train several different predictive models. By comparing the coefficient of determination (R2) of the response surface method (RSM) and five different machine learning models, it is found that the support vector regressor (SVR) has the best performance in this data volume case. Ultimately, the ML resources developed in this work can potentially support the application of AM technology in the assessment of part structural integrity through simulation and can also be integrated into a control loop that can pause or even correct a failing print if the expected filament force-speed pairing is trailing outside a tolerance zone stemming from ML predictions.

Development of metal AM technology for gas turbine components

Mitsubishi Heavy Industries, Ltd. (MHI) Group has been developing additive manufacturing (AM) as a method that can manufacture parts with complex shapes and considering its application to manufacturing processes. In combustor components, application of AM process to rapid prototyping and multi-cluster nozzles for hydrogen or ammonia gas fuel is being considered. In turbine parts, with the aim of improving performance by reducing the amount of cooling air, the adoption of a complex internal cooling structure, which cannot be made with conventional manufacturing methods but can only be made by AM, is being considered. This paper describes design for AM technology for gas turbine components and metal AM process technology such as building simulation based high stiffness support design and pre-set distortion, microstructure control by laser scanning conditions, quality control through in-process monitoring tools and application of AM technology to gas Turbine Components.

3D-Printed models for left atrial appendage occlusion planning: a detailed workflow

PurposeLeft atrial appendage occlusion (LAAO) is a structural interventional cardiology procedure that offers several possibilities for the application of additive manufacturing technologies. The literature shows a growing interest in the use of 3D-printed models for LAAO procedure planning and occlusion device choice. This study aims to describe a full workflow to create a 3D-printed LAA model for LAAO procedure planning.Design/methodology/approachThe workflow starts with the patient’s computed tomography diagnostic image selection. Segmentation in a commercial software provides initial geometrical models in standard tessellation language (STL) format that are then preprocessed for print in dedicated software. Models are printed using a commercial stereolithography machine and postprocessing is performed.FindingsModels produced with the described workflow have been used at the Careggi Hospital of Florence as LAAO auxiliary planning tool in 10 cases of interest, demonstrating a good correlation with state-of-the-art software for device selection and improving the surgeon’s understanding of patient anatomy and device positioning.Originality/value3D-printed models for the LAAO planning are already described in the literature. The novelty of the article lies in the detailed description of a robust workflow for the creation of these models. The robustness of the method is demonstrated by the coherent results obtained for the 10 different cases studied.

Applications of Additive Manufacturing Technologies in Healthcare Sectors During Covid-19 Pandemic

Applications of Additive Manufacturing Technologies in Healthcare Sectors During Covid-19 Pandemic

The application of additive manufacturing technology in pelvic surgery: A bibliometrics analysis.

With the development of material science, additive manufacturing technology has been employed for pelvic surgery, addressing the challenges, such as the complex structure of the pelvis, difficulty in exposing the operative area, and poor visibility, of the traditional pelvic surgery. However, only limited studies have been done to review the research hotspots and trends of the additive manufacturing technology applied for pelvic surgery. In this study, we comprehensively analyzed the literatures related to additive manufacturing technology in pelvic surgery by a bibliometrics analysis and found that additive manufacturing technology is widely used in several aspects of preoperative diagnosis, preoperative planning, intraoperative navigation, and personalized implants for pelvic surgery. Firstly, we searched and screened 856 publications from the Web of Science Core Collection (WoSCC) with TS = (3D printing OR 3D printed OR three-dimensional printing OR additive manufacturing OR rapid prototyping) AND TS = (pelvis OR sacrum OR ilium OR pubis OR ischium OR ischia OR acetabulum OR hip) as the search strategy. Then, 565 of these were eliminated by evaluating the titles and abstracts, leaving 291 pieces of research literature whose relevant information was visually displayed using VOSviewer. Furthermore, 10 publications with high citations were selected by reading all publications extensively for carefully evaluating their Titles, Purposes, Results, Limitations, Journal of affiliation, and Citations. Our results of bibliometric analysis demonstrated that additive manufacturing technology is increasingly applied in pelvic surgery, providing readers with a valuable reference for fully comprehending the research hotspots and trends in the application of additive manufacturing technology in pelvic surgery.

Fatigue properties of resistance spot‐welded maraging steel produced by selective laser melting

AbstractThis research study investigates the fatigue properties of resistance spot welds (RSWs) made from selective laser‐melted (SLMed) maraging steel (MS1) and compares them with dual‐phase (DP) steel RSWs. The findings reveal that MS1 spot welds exhibit superior fatigue properties compared with DP steel RSWs, regardless of the printing orientation of the MS1 substrate. Furthermore, fatigue fracture occurs at the MS1 substrate, with a transition of fracture location observed from MS1 to itself and MS1‐to‐DP600 dissimilar welds. The results of structural stress analysis indicate that the weld nugget diameter is not the only factor affecting the fatigue life. The study also highlights the importance of considering materials inhomogeneity and fracture modes in fatigue life assessment. Based on the findings, the study recommends the development of a new fatigue life prediction curve for spot welds of additive manufacturing (AM) materials. Such a curve would be beneficial in promoting the further application of AM technology for functional parts of design verification vehicles (DCV) and production cars. Overall, the research contributes to the understanding of the fatigue properties of RSWs made from SLMed MS1 and DP steel, which has implications for the design and manufacturing of parts in the automotive industry.

Additive manufacturing technologies in the oral implant clinic: A review of current applications and progress.

Additive manufacturing (AM) technologies can enable the direct fabrication of customized physical objects with complex shapes, based on computer-aided design models. This technology is changing the digital manufacturing industry and has become a subject of considerable interest in digital implant dentistry. Personalized dentistry implant treatments for individual patients can be achieved through Additive manufacturing. Herein, we review the applications of Additive manufacturing technologies in oral implantology, including implant surgery, and implant and restoration products, such as surgical guides for implantation, custom titanium meshes for bone augmentation, personalized or non-personalized dental implants, custom trays, implant casts, and implant-support frameworks, among others. In addition, this review also focuses on Additive manufacturing technologies commonly used in oral implantology. Stereolithography, digital light processing, and fused deposition modeling are often used to construct surgical guides and implant casts, whereas direct metal laser sintering, selective laser melting, and electron beam melting can be applied to fabricate dental implants, personalized titanium meshes, and denture frameworks. Moreover, it is sometimes required to combine Additive manufacturing technology with milling and other cutting and finishing techniques to ensure that the product is suitable for its final application.

Review on development and application of 4D-printing technology in smart textiles

4D printed products can change shape under external stimulation, and the deformation design of material and structure is directly built into the material, which simplifies the manufacturing process from design concept to physical object and allows the object to be automatically assembled and conformed, realizing the integration of product design, manufacturing, and assembly. In recent years, 4D printing technology has also received widespread attention in the smart textile industry. This paper aims to promote the diversified and efficient development of the smart textile industry and expand the scope of the application of additive manufacturing technology. First, the evolution of 4D printing and its intrinsic relationship with 3D printing are examined. Then, the types of 4D printing smart textile technologies and their characteristics are presented, and the influence of relevant parameters of each type of technology on the molding quality, deformation mechanism, and driving performance of printed models is discussed. Materials for 4D printing of smart textiles are further described, including shape memory materials, hydrogels, and elastic liquid crystals. To adapt to the specific properties of textile applications, 4D printing technology has developed from the structural level of textiles to create smart textiles with adjustable shapes, properties, or functions. Then, the applications of 4D printed smart textiles in different fields are summarized. Finally, some problems currently faced by 4D printed smart textiles are discussed, and their prospects are projected.

Taxonomy on the production processes and characterization of powder metallurgy used in additive manufacturing process

Purpose. This article presents a concise and comprehensive review of the technologies that are typically used for manufacturing metal powders as well as the implications that particle features have on the properties of additive manufacturing (AM) techniques. Methodology. We surveyed various experiments that have taken place on the effects of the qualities of the powder and how to guarantee the dependability and reproducibility of the parts that are manufactured as well as ways of optimizing a powders performance. We classified the methods for producing metallic powders and highlighted the benefits, limitations, and image analysis of major production techniques. Findings. The usage of different approaches to metallic powder characterization for the analysis of the physical, mechanical, and chemical processes has contributed to major steps in powder optimization. The characterization of these powders is critical for ensuring adequate additive material dimensions and specifications and recording the properties of powders used in an AM and bridging the gap of comprehension concerning the end output in AM. Originality. This paper provides a thorough analysis of the efforts made in the powder characterization of AM components for the interpretation of the impact on the part materials qualities and characteristics. Metallic powder characterization has contributed to substantial progress toward powder optimization in the analysis of particle structures. Practical value. As the application of AM technology is moving away from the creation of prototypes and toward the production of finished products, it becomes important to understand the powder properties necessary to manufacture high-quality elements consistently.

Design and Construction of a Low-Cost-High-Accessibility 3D Printing Machine for Producing Plastic Components

The additive manufacturing process creates objects directly by stacking layers of material on each other until the required product is obtained. The application of additive manufacturing technology for teaching and research purposes is still limited and unpopular in developing countries, due to costs and lack of accessibility. In this study, an extruding-based 3D printing additive manufacturing technology was employed to design and construct a low-cost-high-accessibility 3D printing machine to manufacture plastic objects. The machine was designed using SolidWorks 2020 version with a 10 × 10 × 10 cm3 build volume. The fabrication was carried out using locally available materials, such as PVC pipes for the frame, plywood for the bed, and Zinc Oxide plaster for the bed surface. Repetier firmware was the operating environment for devices running on the computer operating system. Cura was used as the slicing software. The fabricated machine was tested, and the printer produced 3D components with desired structural dimensions. The fabricated 3D printer was used to manufacture some plastic objects using PLA filament. The recommended distance between the nozzle tip and the bed is 0.1 mm. The constructed 3D printer is affordable and accessible, especially in developing nations where 3D printing applications are limited and unpopular.

Engineering of silicone-based blends for the masked stereolithography of biosilicate/carbon composite scaffolds

Silicone resins, filled with phosphates and other oxide fillers, have been recently proposed as feedstock for the manufacturing of scaffolds with a composition resembling that of commercial Biosilicate® glass-ceramics. Silicones and engineered fillers enable the preparation of novel carbon-containing Biosilicate-based composites and, fundamentally, the easy application of additive manufacturing technologies. After successful demonstration of the applicability of direct ink writing of silicone-based pastes, the present paper is dedicated to preparation of highly porous scaffolds obtained by masked stereolithography, starting from a simple blend of silicone resin with commercial photocurable acrylates. Deviations in the desired phase assemblage were corrected by calibration of the silicone/fillers ratio. The more advanced printing technology, combined with ceramic transformation, allowed fabrication of scaffolds with a complex geometry and a distinctive control of overall porosity.

The Effect of Process-Induced Porosity on Fatigue Properties of Ti6Al4V Alloy via High-Power Direct Energy Deposition

Titanium alloy is widely used in the aviation sector and has become the most important structural material in aircraft manufacturing. However, manufacturing a large-scale titanium component owns a high buy-to-fly ratio due to its poor machinability and expensive price. Over the last decade, the additive manufacturing (AM) technology has developed rapidly and has become a promising processing method for titanium alloys. In the future, in order to enhance processing efficiency and material utilization, a higher laser energy source is supposed to be applied in AM processes. Nevertheless, porosity within the AM fabricated part is the most important issue that restricts the application of AM technology. In the present work, two bulks with different porosities were fabricated using high-power direct energy deposition (HP-DED), and the high cycle fatigue (HCF) performance of the as-build part was tested and compared. The result shows that a lack of fusion (LOF), spherical pores and un-melted particles are the main porosity defects in the as-build part. The shape, size and location of the defect will have a synthetic effect on HCF performance. In addition, the unstable key-hole during the process will facilitate the formation of a pore, which consequently increases the porosity. Online monitoring and closed-loop feedback systems should be established for enhancing the process stability.

Additive Manufacturing Technology for Spare Parts Application: A Systematic Review on Supply Chain Management

Additive manufacturing (AM) is gaining interest among researchers and practitioners in the field of manufacturing. One major potential area of AM application is the manufacturing of spare parts, which affects the availability of the operation and supply chain. The data show that the application and adoption of AM has contributed to a reduction in lead times and inventory, which also contributes to a reduction in holding costs. This paper provides a review of recent work on the application of AM technology specifically for spare parts. The review shows that there are supply chain opportunities and challenges to the adoption of AM in spare parts within various application sectors. Our research reviews both the quantitative and qualitative models used for analysis to meet the emerging needs of the industry. The review also shows that the development of technology and its application is still emerging; therefore, there will be further opportunities to develop better spare parts supply chains to support AM applications. This paper concludes with future research directions.

Wire–powder–arc additive manufacturing: A viable strategy to fabricate carbide ceramic/aluminum alloy multi-material structures

Ceramic/metal composites have been widely studied and applied because of their many advantageous properties. However, limited work on the additive manufacturing (AM) of ceramic controllably reinforced metal matrix composites (MMCs) has been conducted. To customize the compositions and properties at user-defined positions within a single MMC component, we developed a low-cost method, wire–powder–arc additive manufacturing (WPA-AM), for the rapid fabrication of ceramic particles to selectively reinforce aluminum matrix composite (AMC) structures. Multi-material AMC components with the controllable addition of various carbide ceramic particles (B 4 C, SiC, TiC, and WC/W 2 C) have been successfully fabricated via the WPA-AM system. We investigated the effects of the four kinds of ceramic particles on the arc behaviors, the droplet transfer modes in the WPA-AM process, and the forming qualities of the deposited AMC layers. The particle distribution, microstructures, and interfacial characteristics of the AMC structures have been studied. Furthermore, the mechanical properties of the single-AMC and the cyclic laminated multi-AMC structures were comparatively analyzed. This work verified the feasibility of manufacturing ceramic/metal multi-material structures by the WPA-AM process, which will promote the development and application of AM technology.