Progress in Additive Manufacturing

Benč, Marek; Izák, Josef; Walek, Josef; Opěla, Petr; Kopeček, Jarek

doi: 10.1007/s40964-025-01182-6pmid: N/A

This study compares the hot deformation behavior of Inconel 718 superalloy manufactured by the conventional and 3D-printing technology. The effect of subsequent intensive plastic deformation on changes in deformation behavior is also investigated. Both the nickel superalloys prepared by the conventional and 3D-printing ways before and after post-processing by rotary swaging were subjected to uniaxial hot compression tests to characterize a corresponding deformation behavior (via flow stress response) at a temperature range of 900–1200 °C and a strain rate range of 0.1–100 s−1. Slightly different results were obtained at lower strain rates and temperatures. It was further also observed the conventionally prepared specimen way unable to withstand deformation at a temperature of 1200 °C, whereas the specimen using the 3D-printing technology was able to withstand deformation at this temperature range. Microstructure analysis showed that the rotary swaging process applied to 3D printed had a significant effect on grain size refinement and microstructure development with compared to conventionally prepared specimen. The average grain size of the 3D-printed workpiece after rotary swaging process was less than 2 µm. Furthermore, with decreasing deformation temperature and increasing strain rate, the Vickers microhardness measurement showed an increasing microhardness. Subsequent intensive plastic deformation resulted in relatively slight increase in both the flow stress response and microhardness. Maximum values of flow stress response (approximately 710 MPa) and microhardness (approximately 420 HV) were achieved at a combination temperature of 900 °C and strain rate of 10 s−1.

Gupta, Shruti; Gnanamoorthy, R; Kandasubramanian, Balasubramanian

doi: 10.1007/s40964-025-01190-6pmid: N/A

Lattice structures, composed of interconnected elements forming rigid framework, popular for augmenting strength:weight ratio is extensively utilized in applications necessitating minimal material usance with maximum load-bearing and energy-absorption capabilities. Hybrid structures, incorporating bio-inspired architectures such as honeycomb or trabecular bone with truss lattices, exhibit augmented mechanical properties due to their optimized design for load distribution and structural efficiency. The significant advancement in manufacturing such structures involving complexity can be accredited to the ingress of additive manufacturing (AM) techniques which enables the precise replication of intricate geometries and topologies that are often unachievable through conventional manufacturing methods. This technology also allows for material optimization, leading to improved performance characteristics and resource efficiency. The layer-by-layer construction inherent to AM techniques like selective laser sintering and fused deposition modeling facilitates fabrication of customized, high-fidelity structures of lattice. This review offers scrupulous anatomy of design and mechanical properties among lattice structures, with strong emphasis on their comparison to bio-inspired materials. It examines the range of materials utilized in the fabrication of these structures, including metals, polymers, and composite materials. Furthermore, review explores diverse applications of lattice structures in engineering sectors, emphasizing their role in enhancing performance, reducing weight, and achieving superior mechanical properties.Graphical abstract[graphic not available: see fulltext]

Khan, Imran; Amin, Junaid; Abas, Muhammad; Babar, Maheen; Mikail Shah, Syed; Ali, Aashiyan; Rasheed, Adnan; Hira, Fatima

doi: 10.1007/s40964-025-01201-6pmid: N/A

Additive manufacturing plays a crucial role in today's world. This review paper examines the significant advancements in extrusion-based additive manufacturing, focusing particularly on particle-reinforced polymer composites. It highlights the integration of multimaterials and identifies key innovations, challenges, and opportunities in the production of high-performance, application-specific components. The analysis addresses material properties, process optimization, and the potential of these composites to enhance mechanical, thermal, and functional characteristics. By providing a comprehensive review of existing literature and experimental findings, the paper identifies the current limitations, such as achieving uniform reinforcement dispersion and strong interface adhesion. Looking ahead, this paper suggests future directions, including the use of sustainable materials and advanced simulation techniques to address performance gaps. This work serves as a guide for researchers and industry professionals in advancing the next-generation additive manufacturing technologies.

Deep, Akash; Miri Beidokhti, Mojtaba; Piili, Heidi

doi: 10.1007/s40964-025-01202-5pmid: N/A

Powder bed fusion of metals using a laser beam (PBF-LB/M) is a widely adopted additive manufacturing (AM) technique, particularly effective for producing complex geometries and thin-walled structures. While thin powder layers enable high precision and fine surface finishes, they also reduce manufacturing speed, creating a trade-off between quality and productivity. This study explores the relationship between geometrical complexity and manufacturability in PBF-LB/M by developing a specialized numerical framework. A comprehensive review of existing manufacturability evaluation methods, which focusses on feature-based and knowledge-based approaches is presented, with applications across the aerospace, biomedical, and automotive industries. The study highlights the importance of layer thickness as a key process parameter and conducts a preliminary evaluation of its impact on building time and manufacturability. The proposed framework provides step-by-step guidance to support early-stage design decisions, allowing optimization of part geometry for reduced cycle time and cost. Initial validation is performed using industrial case studies and build-time simulations using Aconity and Netfabb software. Although the current focus is on layer thickness, the framework sets the groundwork for future studies that incorporate broader process parameters, contributing to improved manufacturability evaluation and decision-making in AM.

Habib, Numan; Vafadar, Ana; Guzzomi, Ferdinando

doi: 10.1007/s40964-025-01217-ypmid: N/A

Wire arc additive manufacturing (WAAM) has recently gained considerable attention due to its capability to manufacture large-size metal with a length of one meter or above, with good microstructural and mechanical properties. However, the manufacture of critical components exposed to extreme environmental conditions, such as high stresses, remains the focus of most research studies. The applications of WAAM in high-tech industries, such as aerospace and marine modes, remain limited due to metallurgical challenges such as oxidation, porosity, cracking, and deformation, especially for high-strength aluminium alloys, including 6XXX and 7XXX series. The aforementioned metallurgical challenges in WAAM are minimized to some extent by another emerging technology, known as additive friction stir deposition (AFSD). AFSD is capable of manufacturing large-size and high strength (strength equal to or greater than that of the raw material) industrial components with fewer metallurgical defects and refined microstructures. However, this technology is in its developmental stage and possesses some challenges, such as oxidation, which is currently an emerging topic for researchers in metal additive manufacturing (AM). This paper reviews the potential of various additive manufacturing (AM) techniques for the manufacture of high-strength components, using either unweldable virgin or recycled high-strength aluminium alloys. The study also provides a comprehensive overview of the importance of recycling aluminium, as well as the challenges of utilizing aluminium (Al) alloys within metal AM. Considerations related to microstructure, the mechanical properties and metallurgical defects in both these technologies are extensively discussed and compared. The study concludes that both technologies are still being developed and experience various metallurgical issues, which need to be addressed to fully utilize WAAM and AFSD for critical applications. Further, the AFSD process is shown to be a better alternative to the WAAM process in the fabrication of Al components, where it possesses less metallurgical issues, higher strength and more refined microstructures. The literature suggests ultimate tensile stress (UTS) and average elongation percentage during AFSD in the range of 197.3 MPa–306 MPa and 8.6%–39% for Al alloys, respectively. However, slightly better UTS values in the range of 344 MPa–349 MPa and significant reduction in average elongation percentage to 5% is noted during WAAM process. Furthermore, AFSD exhibited significantly higher microhardness values (40.8 HV–151.4 HV) when compared to WAAM (73 HV–111 HV). Accordingly, the study notes that further numerical and experimental studies are needed to fully understand material flow in stirring zones during the AFSD process.

Moghaddasi, Mohammad; Oktay, Busra; Bingol, Ayse Betul; Yanikoglu, Reyhan; Ciftci, Fatih; Ustundag, Cem Bulent

doi: 10.1007/s40964-025-01245-8pmid: N/A

Four-dimensional (4D) bioprinting integrates with stimuli-responsive biomaterials to create dynamic constructs capable of adapting their shape, properties, or bioactivity in response to specific cues. This systematic review, conducted in accordance with established systematic review guidelines, examines 77 studies sourced from PubMed, Scopus, Web of Science, and bioRxiv. Extrusion-based bioprinting is predominant (≈80%), with fused deposition modeling, stereolithography, and inkjet methods also employed. Physical stimuli, including temperature, humidity, and mechanical forces, are the most commonly utilized alongside less frequently seen chemical and biological cues. Applications in tissue engineering focus on cartilage, bone, neural, vascular, muscle, and soft-tissue regeneration, where programmable constructs show improved tissue morphogenesis. In drug delivery and disease-modeling, reactive oxygen species-, pH-, enzyme-, and temperature-triggered systems facilitate the targeted release of growth factors, genes, and chemo-/immunotherapeutics. Moreover, most of the studies employing shape-morphing and shape memory hydrogels focus on broader biomedical applications. These findings collectively indicate a developing field with the potential to advance next-generation tissue engineering therapies and drug-release systems.

Chekkaramkodi, Dileep; Hisham, Muhammed; Ahmed, Israr; Ali, Murad; Shebeeb, C. Muhammed; Butt, Haider

doi: 10.1007/s40964-025-01247-6pmid: N/A

This review focuses on the critical role of post-processing techniques in enhancing the performance of 3D printed photonic components. While 3D printing enables the fabrication of complex optical structures with high customization and geometric freedom, the as-printed parts often lack the surface smoothness, light transmission quality, and dimensional precision required for functional photonics. To bridge this gap, we provide a comprehensive overview of key post-processing methods, including chemical treatments, thermal annealing, laser ablation, polishing, and optical coatings specifically applicable to improving optical quality. We also discuss current challenges in post-processing 3D printed optics, such as high initial costs, long processing times, and material compatibility issues. Advances in material science, computational design, and process optimization are identified as promising avenues for overcoming these limitations. In addition, the review briefly summarizes the 3D printing technologies most relevant to photonics extrusion, powder bed fusion, and vat photopolymerization, highlighting their capabilities in producing highly customized optical components. By focusing on the interface between 3D printing and post-processing, this work offers guidance for developing next-generation optical devices that meet industry standards. These insights are particularly relevant to applications in medical imaging, telecommunications, and optical sensing.

Bi, Jiang; Zou, Jinliang; Zhu, Liangjin; Wu, Liukun; Li, Shide; Starostenkov, Mikhail Dmitrievich; Dong, Guojiang

doi: 10.1007/s40964-025-01170-wpmid: N/A

The laser powder bed fusion (LPBF) technology is employed to manufacture the 316L-CuCrZr bi-material. The microstructure characteristics of 316L-CuCrZr gradient specimen including grain size, element distribution, and precipitate phase were analyzed. Lots of Fe-rich and Cu-rich phases with different shapes are found at the interface zone of 316L steel and LPBF-printed CuCuZr alloy, which indicates that sufficient element diffusion was occurred. The ε-Cu, γ-Fe and Cr phases are also identified by selected area electron diffraction (SAED). Furthermore, due to the synergistic effect of fine grain strengthening, precipitation strengthening, and heterostructure, the LPBF-fabricated 316L-CuCrZr interface with excellent joining strength is obtained. The specimen prepared with 450 W-400 mm/s exhibits excellent mechanical performance (the ultimate tensile strength: 290 MPa; the yield strength: 208 MPa; the elongation: 20%). After aging treated at 450 ℃ for 2 h, the ultimate tensile strength and yield strength of the specimen reached 521 MPa and 434 MPa, respectively. This research can provide some reasonable suggestions and guidance for preparing multi-material structures.

Kumar, S. Pratheesh; Yuvarajan, Rithika Jayabharathi

doi: 10.1007/s40964-025-01171-9pmid: N/A

The laser direct metal deposition (LDMD) process, an additive manufacturing technique, creates components by fusing materials layer-by-layer, with part quality significantly influenced by process parameters. Optimizing these parameters is essential for improving material efficiency and part durability. This study addresses the need to enhance powder catchment efficiency (PCE) in LDMD, specifically for Stelcar 65 alloy, a material used in high-wear and high-temperature applications. Utilizing process variables such as scanning speed and laser power, this research employs mathematical–statistical RSM to identify ideal conditions for maximizing PCE. Experimental data were analyzed and optimized, resulting in a PCE model that closely matched empirical results with a 98.52% accuracy. The findings underscore that optimal parameter selection can substantially elevate component quality in LDMD processes. These insights are particularly beneficial for manufacturers in aerospace, tooling, and other high-precision industries, enabling the efficient application of Stelcar 65 in producing superior-quality components.

Kumar, S. Sai; Muthu, N.; Panda, Biranchi

doi: 10.1007/s40964-025-01172-8pmid: N/A

This study explores the structural behavior of 3D-printed concrete (3DPC) walls through numerical simulations, with a focus on the impact of interfaces between printed layers. The numerical analysis is performed in ABAQUS®, with the concrete damage plasticity (CDP) model used to represent the printed layers, while cohesive zone modelling (CZM) is applied to simulate the interfacial behavior. A notable aspect of this work is the implementation of a modified damage equation that introduces an exponent to control damage evolution during compression, aligning it with the constitutive response derived from analytical expressions in the literature. A series of parametric studies are conducted to assess how different parameters, including the damage exponent, maximum compressive strength, and cohesive parameters, influence structural performance. The numerical results are compared with experimental data to validate the approach, demonstrating the critical role of interface behavior in the overall structural integrity of 3DPC walls. This research contributes to the understanding of 3DPC wall performance, providing a framework for future investigations into the optimization of 3DPC structures. In addition, the impact of different infill designs on the structural performance of 3DPC walls is explored, highlighting the importance of infill geometry in enhancing wall stability.