High performance realization of functionally graded materials based on integrated optimal design and additive manufacturing: A review

Roadmap for Additive Manufacturing: Toward Intellectualization and Industrialization

Perspectives on additive manufacturing for warhead applications

Functionally graded materials (FGM) have recently attracted a lot of research attention in the wake of the recent prominence of additive manufacturing (AM) technologies. The continuously varying spatial composition profile of two or more materials affords FGM to possess properties of multiple different materials simultaneously. Emerging AM technologies enable manufacturing complex shapes with customized multifunctional material properties in an additive fashion. In this paper, we focus on providing an overview of research at the intersection of AM techniques and FGM objects. We specifically discuss FGM modeling representation schemes and outline a classification system to classify existing FGM representation methods. We also highlight the key aspects such as the part orientation, slicing, and path planning processes that are essential for fabricating FGM object through the use of multimaterial AM techniques.

This paper thoroughly examines the advancements and challenges in the field of additively manufactured Functionally Graded Materials (FGMs). It delves into conceptual approaches for FGM design, various manufacturing techniques, and the materials employed in their fabrication using additive manufacturing (AM) technologies. This paper explores the applications of FGMs in diverse fields, including structural engineering, automotive, biomedical engineering, soft robotics, electronics, 4D printing, and metamaterials. Critical issues and challenges associated with FGMs are meticulously analyzed, addressing concerns related to production and performance. Moreover, this paper forecasts future trends in FGM development, highlighting potential impacts on diverse industries. The concluding section summarizes key findings, emphasizing the significance of FGMs in the context of AM technologies. This review provides valuable insights to researchers, practitioners, and stakeholders, enhancing their understanding of FGMs and their role in the evolving landscape of AM.

Growing consciousness regarding the environmental impacts of additive manufacturing (AM) processes has led to research focusing on quantifying their environmental impacts using Life Cycle Assessment (LCA) methodology. The main objective of this paper is to review the state of the art of the existing LCA studies of AM processes. In this paper, a systematic literature review is carried out where a total of 77 papers focusing on LCA, including social-Life Cycle Assessment (S-LCA), are analyzed. Accordingly, the application of LCA methodology to different AM technologies was studied and different research themes such as the goal and scope of LCA studies, life cycle inventory data for different AM technologies, AM part quality and mechanical properties, the environmental, economic, and social performances of various AM technologies, and factors affecting AM´s sustainability potential were analyzed. Based on the critical analysis of the existing research, five major shortcomings of the existing research are realized: (i) some AM technologies are under studied; (ii) more focus only on the environmental sustainability dimension of AM, neglecting its economic and social dimensions; (iii) exclusion of AM pat quality and its mechanical performance from the sustainability assessment; (iv) not enough focus on the life cycle stages after product manufacture by AM; (v) effect of different product variables on AM´s sustainability not studied extensively. Lastly, based on these shortcomings realized, the following research directions for future works are suggested: (i) inclusion of new AM materials and technologies; (ii) transition to a triple-bottom-line sustainability assessment considering environmental, economic, and social dimensions of AM; (iii) extending the scope of LCA studies to post-manufacture stages of AM products; (iv) development of predictive environmental impact and cost models; (v) integration of quality and mechanical characterization with sustainability assessment of AM technologies.

PurposeThe usage of additive manufacturing (AM) technology in industries has reached up to 50 per cent as prototype or end-product. However, for AM products to be directly used as final products, AM product should be produced through advanced quality control process, which has a capability to be able to prove and reach their desire repeatability, reproducibility, reliability and preciseness. Therefore, there is a need to review quality-related research in terms of AM technology and guide AM industry in the future direction of AM development.Design/methodology/approachThis paper overviews research progress regarding the QC in AM technology. The focus of the study is on manufacturing quality issues and needs that are to be developed and optimized, and further suggests ideas and directions toward the quality improvement for future AM technology. This paper is organized as follows. Section 2 starts by conducting a comprehensive review of the literature studies on progress of quality control, issues and challenges regarding quality improvement in seven different AM techniques. Next, Section 3 provides classification of the research findings, and lastly, Section 4 discusses the challenges and future trends.FindingsThis paper presents a review on quality control in seven different techniques in AM technology and provides detailed discussions in each quality process stage. Most of the AM techniques have a trend using in-situ sensors and cameras to acquire process data for real-time monitoring and quality analysis. Procedures such as extrusion-based processes (EBP) have further advanced in data analytics and predictive algorithms-based research regarding mechanical properties and optimal printing parameters. Moreover, compared to others, the material jetting progresses technique has advanced in a system integrated with closed-feedback loop, machine vision and image processing to minimize quality issues during printing process.Research limitations/implicationsThis paper is limited to reviewing of only seven techniques of AM technology, which includes photopolymer vat processes, material jetting processes, binder jetting processes, extrusion-based processes, powder bed fusion processes, directed energy deposition processes and sheet lamination processes. This paper would impact on the improvement of quality control in AM industries such as industrial, automotive, medical, aerospace and military production.Originality/valueAdditive manufacturing technology, in terms of quality control has yet to be reviewed.

PurposeThis study provides an up-to-date review of additive manufacturing (AM) technologies and guidance for selecting the most appropriate ones for specific applications, taking into account the main features, strengths, and limitations of the existing options.Design/methodology/approachA literature review on AM technologies was conducted to assess the current state-of-the-art. This was followed by a closer examination of different AM machines to gain a deeper insight into their main features and operational characteristics. The conclusions and data gathered were used to formulate a classification and decision-support framework.FindingsThe findings indicate the building blocks of the selection process for AM technologies. Furthermore, this work shows the suitability of the existing AM technologies for specific cases and points to opportunities for technological and decision-support improvements. Lastly, more standardization in AM would be beneficial for future research.Practical implicationsThe proposed framework offers valuable support for decision-makers to select the most suitable AM technologies, as demonstrated through practical examples of its utilization. In addition, it can help researchers identify the limitations of AM by pinpointing applications where existing technologies fail to meet the requirements.Originality/valueThe study offers a novel classification and decision-support framework for selecting AM technologies, incorporating machine characteristics, process features, physical properties of printed parts, and costs as key features to evaluate the potential of AM. Additionally, it provides a deeper understanding of these features as well as the potential opportunities for AM and its impact on various industries.

Purpose The purpose of this paper is to provide a systematic analysis about the effects of additive manufacturing (AM) technology adoption on supply chain management (SCM) processes and SCM components in an engineer-to-order environment. Design/methodology/approach Based on two explorative case studies from the hearing systems industry, the impact of AM technology adoption on SCM processes and SCM components is investigated. General systems theory and the contingency approach serve as theoretical underpinning. Findings Not only the internal processes and management activities, e.g. in manufacturing and order fulfillment, of producers are affected by a changeover to AM, but also the SCM processes and components relating to the supply and demand side of a firm’s supply chain. Endogenous and AM technology-related factors are contingency factors that help to explain differing effects of AM technology adoption on SCM processes and SCM components. Research limitations/implications It is proposed that AM’s ability to economically build custom products provides the potential to alleviate the common dilemma between product variety and scale economies. Practical implications Manufacturing firms are encouraged to consider the potential effects of AM on SCM processes and SCM components when deciding whether to adopt AM technologies in the production of industrial parts. Originality/value The research adds to the widely unexplored effects that AM technology usage in customized parts production has on SCM processes and components. Moreover, the general lack of case studies analyzing the implications of AM technology adoption from a supply chain perspective is addressed. The resulting propositions may serve as a starting point for further research on the impact of AM in engineer-to-order supply chains.

Metal matrix composites (MMCs) are frequently employed in various advanced industries due to their high modulus and strength, favorable wear and corrosion resistance, and other good properties at elevated temperatures. In recent decades, additive manufacturing (AM) technology has garnered attention as a potential way for fabricating MMCs. This article provides a comprehensive review of recent endeavors and progress in AM of MMCs, encompassing available AM technologies, types of reinforcements, feedstock preparation, synthesis principles during the AM process, typical AM-produced MMCs, strengthening mechanisms, challenges, and future interests. Compared to conventionally manufactured MMCs, AM-produced MMCs exhibit more uniformly distributed reinforcements and refined microstructure, resulting in comparable or even better mechanical properties. In addition, AM technology can produce bulk MMCs with significantly low porosity and fabricate geometrically complex MMC components and MMC lattice structures. As reviewed, many AM-produced MMCs, such as Al matrix composites, Ti matrix composites, nickel matrix composites, Fe matrix composites, etc, have been successfully produced. The types and contents of reinforcements strongly influence the properties of AM-produced MMCs, the choice of AM technology, and the applied processing parameters. In these MMCs, four primary strengthening mechanisms have been identified: Hall–Petch strengthening, dislocation strengthening, load transfer strengthening, and Orowan strengthening. AM technologies offer advantages that enhance the properties of MMCs when compared with traditional fabrication methods. Despite the advantages above, further challenges of AM-produced MMCs are still faced, such as new methods and new technologies for investigating AM-produced MMCs, the intrinsic nature of MMCs coupled with AM technologies, and challenges in the AM processes. Therefore, the article concludes by discussing the challenges and future interests of AM of MMCs.

Professor Akinlabi’s research and her team has focused on the field of advanced and modern manufacturing processes like Laser Additive Manufacturing (AM), in particular laser material processing. Her other research work is focused on laser metal deposition and functionally graded materials of titanium-based alloys and other materials. Some of the studies she has been involved in focus on cladding titanium with titanium carbide for enhanced wear properties, the cladding of titanium alloy biological implants with hydroxyapatite (HAP) for improved osteo-integration, and the cladding of Grade 5 titanium alloy with copper for improved corrosion properties for marine applications. Akinlabi focuses her investigations on the development of advanced metallic coatings on Ti-6Al-4V substrate using additive manufacturing technology for improved surface performance; with targeted applications in the aerospace, automotive, and shipbuilding industries. This work makes a substantial contribution to knowledge by bringing the theoretical clarity and experimental studies required for the effective assessment of surface degradation mechanisms in additive manufactured Ti-6Al-4V alloy. This is ascribed to the elimination of high residual stresses and crack formation through the optimization of laser processing parameters, leading to enhanced quality of the coatings, surface adhesion between the substrate and the reinforcement materials, microstructural evolution and thus improved mechanical properties. Her research was developed to produce advanced innovative corrosion-wear resistant coatings with enhanced hardness, tribological property, and sustainable anti-corrosion performance thereby, consequently lengthening the lifespan and durability of titanium and its alloys, eliminating material loss and equipment damage, minimizing cost of maintenance, and reduced failure of this material. Despite all the benefits derived from AM technology, there are still a lot of unresolved issues with the technology that has hindered its performance and commercialisation thereby limiting its application to high tolerant utilizations. Professor Akinlabi research on additive manufacturing techniques had produced near-net-shape, light weight and high strength components which has gradually revolutionized the manufacturing sector. The use of the technology is now providing sustainable production benefits, as ability to repair and manufacture components can now be employed to increase product life circle. Against this background, the Additive Manufacturing technology is in itself referred to as a technology of the future despite its versatile applications in the industry. On the other hand, Functionally Graded Materials (FGMs) are advanced materials usually developed for specific and tailored applications. The FGMs also referred to as materials of the future as its applications are not yet fully explored for tailored applications. In this talk, Prof Akinlabi shared some of her research endeavours in the field of AM and FGMs, and also shared the scope on the primary objectives of the joint project which was to be undertaken on FGM of Titanium alloy and Titanium Carbide.

To drive emissions reduction and performance improvement of the gas turbines, Siemens Energy is working continuously with the development and implementation of new advanced technologies. This paper describes the integration of groundbreaking additive manufacturing (AM) technology into the design and manufacturing of gas turbine components. Siemens Energy is already implemented AM technology in the design and manufacturing of combustor components to run gas turbines on green fuels. As an example, the implementation of AM burners in medium-size gas turbines (MTG) with Dry Low Emission (DLE) combustors expands their fuel flexibility and ability to run on hydrogen-rich gases. Today, the SGT-600, -700 and -800 can be offered to run on fuel with up to 75 vol% H2 in the fuel. Integrating AM technology into the design and manufacturing of turbine’s components, such as vanes and blades, leads to substantial improvements in gas turbine efficiency and, as a result, gas turbine fuel consumption and emissions reduction. This paper describes the infusion of AM technology into the design and manufacturing of hot gas path components, in the turbine vanes of Siemens Energy gas turbines. Improving the efficiency of turbine and turbine components is driven by utilizing new advanced cooling systems and better aerodynamics enabled by the practically unlimited capability of AM design and manufacturing. Successful design, manufacturing and field validation of AM vanes in Siemens Energy SGT-700 gas turbine are presented and discussed in this paper. The reliable operation of AM components under real field operation conditions has been confirmed by the total accumulated field experience, which already exceeds 1,700,000 operating hours.

Additive Manufacturing (AM) is a well-known technology, first patented in 1984 by the French scientist Alain Le Mehaute [...]

Integrating parametric design and additive manufacturing knowledge in industrial design education

Overview of 3D additive manufacturing (AM) and corresponding AM composites

Offshore renewable energy structures are subject to harsh environments with loading from wind, wave, and tides which introduce fatigue damage in corrosive and erosive environments. An effective approach that has been found to improve mechanical and fatigue resistance of engineering structures is employment of Additive Manufacturing (AM) technology. However, little research has been conducted for implementation of AM technology in offshore renewable energy structures. This study aims to collate and critically discuss the advantages that AM technology can offer to enhance the lifespan of offshore renewable energy structures. In addition to fatigue life improvement, the potential of AM technology to enhance corrosion and erosion resistance in offshore renewable energy structures has been explored. It has been found in this study that among the existing AM techniques, Wire Arc Additive Manufacturing (WAAM) offers promising potentials for life enhancement of offshore wind turbine and tidal turbine support structures. Early research into the potential of using WAAM to create corrosion resistance coatings and components highlights many benefits achieved from this new emerging manufacturing technology, but further research is required to justify the use of the processes for commercial applications. In terms of erosion and wear resistance even less research has been conducted but initial findings show that AM has the potential to add a great level of resistance compared to the wrought material. This study presents the key advantages that AM technology offers to enhance the design life and integrity of offshore renewable energy structures as a first step towards unlocking the great potentials of AM for consideration and implementation in the energy transition roadmap.