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Item type:Publication, Access status: with files , Systematic study of the interplay between laser beam shape, energy input, and hatch spacing in PBF-LB/M of Ti-6Al-4V: experiments and numerical modeling(Elsevier, 2026-07-17); ; ; ; Programmable laser beam shaping tailors the spatial irradiance distribution in laser powder bed fusion (PBF-LB/M), enabling control over melt-pool geometry and defect formation. However, the coupled effects of beam shape, hatch spacing (track overlap), and energy input on densification and microstructural development remain insufficiently understood. Accordingly, Ti-6Al-4V is studied using single-track experiments, cube builds, and 3D transient multiphysics simulations across three ring-type beam profiles ranging from relatively core-weighted to strongly ring-dominated. Single tracks spanning a power–speed matrix (linear energy density, P/v) quantified melt-pool width, depth, and molten area and mapped stability regimes (fragmentation, necking, stable) and transition thresholds with increasing energy input. Cube specimens mapped relative density versus beam mode, areal energy density AEDh = P/(v h) (J/mm2), hatch spacing h, and geometric ratios h/d (d: effective beam diameter) and W/h (W: melt-pool width). Near-full density (~99.9%) was achieved for all profiles at AEDh ≥ 2.8–3.0 J/mm2; relatively more core-weighted profiles reached this at lower AEDh, whereas ringdominated profiles required higher input to suppress lack-of-fusion. Density dropped when h/d≳1, while W/h≳ 1.2 preserved high density. Microstructure and Vickers microhardness (HV0.2) were assessed across AEDh. All conditions exhibited martensitic α′ microstructures, and microhardness remained ≈360–395 HV0.2, converging once near-full density was reached. Simulations showed that ring-dominated density loss arises from insufficient inter-track remelting depth (cusp formation) despite lateral overlap, requiring higher overlap ratios for full fusion. Thermal gradients (G) and solidification rates (R) placed all cases in the columnar growth regime; higher G/R in more core-weighted profiles is consistent with stronger grain continuity than the more refined ringdominated structures.Publicationtype: Journal Article10 18 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Porosity and elevated-temperature tensile response of PBF-LB/M Ti-6Al-4V across laser beam profiles mapped using a spot-size-aware energy metricLaser beam shaping in PBF-LB/M modifies the spatial laser energy distribution, affecting melt-pool evolution, defect formation, and mechanical response. Ti-6Al-4V was processed using Gaussian, core–ring, and ring-dominated beam profiles. Measured beam maps were used to determine the effective beam diameter in a modified energy metric (VEDM, J mm⁻² s⁻¹/²) for cross-mode comparison. Densification and pore characteristics were assessed in cubes and tensile specimens. Core–ring and ring-dominated profiles transitioned from lack-of-fusion defects at low input to near-full density at higher input, whereas Gaussian shifted toward keyhole-type porosity at the highest input. At VEDM = 332 J mm⁻² s⁻¹ /², the µCT-scanned tensile gauge regions showed lower relative density for Gaussian (∼98.6%) than for core–ring and ring-dominated conditions (∼99.8%). Tensile specimens produced with Gaussian and ring-dominated beams were tested at RT, 200 °C, and 400 °C. All conditions showed temperature-dependent softening. However, at high VEDM and 400 °C, the ring-dominated condition retained higher ductility (∼10%) than the Gaussian condition (∼7%), while maintaining a comparable peak stress. Fractography showed pore-assisted initiation in the Gaussian condition and ductile tearing with pronounced necking in the ring-dominated condition. Overall, elevated-temperature tensile performance was primarily associated with pore type and severity, while VED<inf>M</inf> provides a practical framework for cross-mode comparison.Publicationtype: Journal Article11 13 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Advancing laser powder bed fusion of metals via tailored laser beam shaping: a critical reviewLaser beam shaping is increasingly explored to enhance Laser Powder Bed Fusion of Metals (PBF-LB/M) by controlling the spatial energy distribution within the laser spot. While conventional Gaussian beams remain widely used in commercial systems, their concentrated energy input can promote steep thermal gradients and localized overheating, which may restrict process stability, productivity, and part quality. This review critically synthesizes recent progress in laser beam shaping for PBF-LB/M, with emphasis on work from 2020 to early 2026. Compared with earlier reviews that mainly focused on optical implementation or broader laser–material processing concepts, this review integrates beam-shape generation with melt-pool dynamics, defect formation, surface quality, microstructural evolution, mechanical response, productivity, and emerging shape-aware process descriptors. The discussion shows how profiles such as core–ring, ring-dominant, top-hat, and elliptical beams can broaden stable process windows, suppress spatter and keyhole porosity, and promote more uniform thermal histories, with implications for surface quality, mechanical isotropy, and build efficiency. Modeling and simulation studies are also summarized to clarify the coupled heat-fluid–solid interactions controlling melt-pool behavior, thermal gradients, and solidification kinetics. Furthermore, major implementation challenges such as optical integration, energy-delivery stability, process reproducibility, and the lack of standardized beam descriptors are summarized. The review concludes by outlining emerging research directions aimed at enabling practical, reliable, and industrial-scale adoption of beam-shaping technologies in additive manufacturing.Publicationtype: Review Article15 29 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Role of laser beam shape and energy density in modulating surface quality, porosity, microstructure, and mechanical properties of PBF-LB/M Ti-6Al-4V(Elsevier, 2026-01-03); ; ; ; Beam shaping has recently gained attention as a means to mitigate the thermal gradients and melt-pool instabilities associated with conventional Gaussian beams in laser powder bed fusion (PBF-LB/M), which often lead to surface roughness, defects, and microstructural inconsistency. This study examines the effects of different beam shapes and volumetric energy densities (VEDs) on the surface quality, porosity, microstructure, and mechanical response of Ti-6Al-4V. Cubic specimens were fabricated on an Aconity MIDI+ system using Gaussian, core-ring, and ring beam profiles over a VED range of 78–341 J/mm³. The results show that beam shaping with optimized VED reduces porosity, refines microstructure, and enhances mechanical performance. The Gaussian beam performed well at low VEDs (≤130 J/mm³) but exhibited increased surface roughness and keyhole porosity at higher energy inputs (≥150 J/mm³), whereas the ring-based beams initially showed higher porosity at low VEDs but achieved ∼99.97 % relative density and smoother surfaces at higher VEDs. The ring beam promoted stable conduction-mode melting, continuous prior-β grain growth, refined α′ martensitic microstructures, and strong crystallographic texture. From a mechanical perspective, Vickers hardness values (370–400 HV) correlated with the observed microstructural features. In addition, the Gaussian beam exhibited higher indicative strength at low VEDs but deteriorated with increasing energy input, whereas the ring beam showed the opposite trend, reaching an ultimate tensile strength of 1192 MPa and ∼21 % ductility under optimal conditions. Beam behavior was further evaluated using areal energy density (AED) normalized to the melt-pool width, indicating that melt-pool stability and the resulting surface quality, porosity, and microstructural evolution are primarily influenced by the spatial distribution of laser energy rather than nominal energy metrics alone. These findings provide a physical basis for laser beam shaping as an effective approach to broaden the stable processing window and achieve defect-free, texture-controlled Ti-6Al-4V components.Publicationtype: Journal Article17 29 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Effects of laser beam shaping on Ti-6Al-4V single tracks in PBF-LB/M: A study with Aconity MIDI+(Elsevier, 2025-08-23); ; ; ; The application of beam shaping is gaining increasing interest in laser-based additive manufacturing (AM) technologies, as it revolutionizes the process by providing additional control over incident energy distribution and the resultant microstructure and mechanical properties of the manufactured part. This study provides a comprehensive analysis of how different laser beam profiles (Mode 0, Mode 3, Mode 6), applied via the Aconity MIDI+ system, in combination with varied layer thicknesses (30 µm, 60 µm, and 90 µm) and linear energy inputs (up to 1.0 J/mm), influence single-track formation, surface morphology, roughness, and melt pool behavior in the Laser Powder Bed Fusion (PBF-LB/M) process of Ti-6Al-4V, offering new insights essential for process optimization. To further elucidate these effects, a complementary FEM model was used to analyze how beam shape affects melt pool dynamics and overall process stability. The findings reveal that transitioning from a conventional Gaussian beam (Mode 0) to a ring-shaped beam (Mode 3 and Mode 6) promotes conduction-mode melting, resulting in enhanced process stability and smoother melt track formation at higher linear energy densities. These beam profiles reduce certain defects, including spattering and balling, while producing wider and more stable melt tracks. Conversely, Mode 0 generates deeper melt pools, increasing the likelihood of keyholing and tracks surface roughness at elevated energy levels. While a thinner layer (∼30 µm) facilitates stable and smoother track formation across all beam profiles, thicker layers (≥60 µm) exacerbate surface roughness and defects, especially with Mode 0. In contrast, the ring-shaped beams produce wider, smoother, and more stable melt tracks at higher energy inputs (∼0.6–1.0 J/mm) with thicker layers. These insights are particularly valuable for high-performance applications in aerospace and biomedical industries, where precise control over surface quality and defect formation in Ti-6Al-4V components is essential for meeting certification standards and ensuring production efficiency. Overall, these findings highlight the critical role of beam shaping, layer thickness, and energy input in achieving stable melt tracks and improving the consistency and reliability of the PBF-LB/M process.Publicationtype: Journal Article30 42 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: without files , Revolutionizing the future of smart materials: a review of 4D printing, design, optimization, and machine learning integration(Wiley, 2025-02-25); ; ; ; With technological advancement and development, there is a tremendous increase in demand for different smart materials because of their stimulation from external sources. Moreover, the time-dependent response of smart materials provides insight into the fabrication of these materials using 4D printing (4DP) techniques. Hence, this study presents a comprehensive review of the 4DP of smart materials. The review covers different aspects of smart material, from design and optimization to printing. Herein, smart materials have been discussed in detail based on the physical, biological, and chemical stimuli-responsive and their subtype's behavior. For designing smart materials, different usage of tools such as new designing software, finite element analysis, and machine learning are also discussed. The design of smart materials is challenging because of the different responsive natures and complexity of design and mechanisms. Hence, a detailed review of present 3D printing techniques, the use of 4DP, and how future applications can be incorporated with smart material and 4DP is presented. With the help of machine learning, the fabrication of smart materials using 4DP is also discussed. The review provides future directions for fabricating smart materials using 4DP. The design and printing challenges of smart materials for future utilization have also been comprehensively covered.Publicationtype: Review Article20 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Additive manufacturing of ceramics via the laser powderbed fusion process(American Ceramic Society, 2025-02-22); ; ; ; Additive manufacturing (AM) of ceramics presents both exciting opportunities and significant challenges, particularly with the laser-based AM processes. Ceramics are known for their special properties, such as high strength, corrosion resistance, and temperature stability, but their inherent brittleness and high processing demands make AM more complex. This review provides an updated overview of the most common AM techniques for ceramics, including direct energy deposition, binder jetting, laminated object manufacturing, and material extrusion-based techniques. However, the focus is placed on the laser powder bed fusion (LPBF) of ceramics, a technique that has gained increasing attention for its ability to fabricate complex ceramic parts with enhanced quality. The review delves into the key causes of critical defects commonly observed in LPBF, such as porosity, cracking, spattering, and surface roughness. Recent advancements in addressing these issues are discussed, along with the limitations of current defect prevention strategies. Furthermore, the review provides an updated analysis of the mechanical properties of LPBF-fabricated ceramics, giving insights into how processing parameters influence the performance of ceramic LPBF-printed parts. Modeling and simulation techniques are also reviewed, highlighting their role in enhancing understanding of ceramic behavior during LPBF. Overall, this review highlights recent progress and current challenges in ceramic AM techniques, while exploring future research opportunities, such as process optimization and defect prevention strategies.Publicationtype: Review Article64 48 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Comparative analysis of laser power, pure titanium, and titanium alloy effects on dendrite growth and surface morphology of TiO2-ceramic(American Institute of Physics (AIP), 2024-10-29); ; ; Despite several challenges, including the inherent brittleness of ceramics, inadequate melting of the powder, and the formation of microstructural defects, laser powder bed fusion remains a promising method for ceramic fabrication. This research looks at the intricate relationship between laser power as a dominant factor in energy density, the influence of pure titanium (Ti) and titanium alloy (Ti-6Al-4V) additives on the laser fabrication of TiO2-based ceramics, and the resultant microstructural aspects, with a particular emphasis on dendritic growth and solidification defects. The research findings revealed that changing the laser energy density has a substantial influence on the dendrite growth and solidification rate of TiO2 ceramic. However, in addition to optimizing the laser power, the addition of metal material additives also plays a significant role in regulating the melting state and controlling the part defects in ceramics. The findings support that the mixing of pure titanium showed a relatively favorable influence, enhancing the melting condition of TiO2 and yielding a smooth surface with reduced defects. Conversely, the addition of a titanium alloy (Ti-6Al-4V) has a comparatively lower positive effect and led to the formation of substantial dendrites, solidification shrinkage, and significant fractures. The change in the scanning strategy from zigzag to island has no noticeable effect on the surface morphology and dendrite formation but contributes to controlling the spattering and crack propagation.Publicationtype: Journal Article22 35 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , A machine learning approach for mechanical component design based on topology optimization considering the restrictions of additive manufacturing(Multidisciplinary Digital Publishing Institute (MDPI), 2024-10-01); ; ; ; Additive manufacturing (AM) and topology optimization (TO) emerge as vital processes in modern industries, with broad adoption driven by reduced expenses and the desire for lightweight and complex designs. However, iterative topology optimization can be inefficient and time-consuming for individual products with a large set of parameters. To address this shortcoming, machine learning (ML), primarily neural networks, is considered a viable tool to enhance topology optimization and streamline AM processes. In this work, a machine learning (ML) model that generates a parameterized optimized topology is presented, capable of eliminating the conventional iterative steps of TO, which shortens the development cycle and decreases overall development costs. The ML algorithm used, a conditional generative adversarial network (cGAN) known as Pix2Pix-GAN, is adopted to train using a variety of training data pairs consisting of color-coded images and is applied to an example of cantilever optimization, significantly enhancing model accuracy and operational efficiency. The analysis of training data numbers in relation to the model’s accuracy shows that as data volume increases, the accuracy of the model improves. Various ML models are developed and validated in this study; however, some artefacts are still present in the generated designs. Structures that are free from these artefacts achieve 91% reliability successfully. On the other hand, the images generated with artefacts may still serve as suitable design templates with minimal adjustments. Furthermore, this research also assesses compliance with two manufacturing constraints: the limitations on build space and passive elements (voids). Incorporating manufacturing constraints into model design ensures that the generated designs are not only optimized for performance but also feasible for production. By adhering to these constraints, the models can deliver superior performance in future use while maintaining practicality in real-world applications.Publicationtype: Journal Article42 69 - Some of the metrics are blocked by yourconsent settings
Item type:Publication, Access status: with files , Material extrusion of metals: Enabling multi-material alloys in additive manufacturing(Elsevier, 2024-03); ; ; ; This article discusses the use of Material Extrusion of Metals (MEX/M - defined in ISO/ASTM 52900) technology for producing multi-material components, which offers a cost-effective and efficient method without requiring major adaptations to existing equipment. The article presents the successful manufacture of 316L/17–4PH multi-alloy steel cubes for four different sintering temperatures using commercially available equipment and feedstock. The feasibility study of the multi-material samples was supported by analyzing the shrinkage, optical density, and microstructure as output parameters. Unlike other works, the multi-material produced parts showed regular shrinkage behaviour and no major deformation, indicating the possibility of creating functional parts without the need for post-processing. Interestingly, relevant findings were made on the different shrinkage values obtained for the constellations considered. Further in-depth investigation of each parameter involved in all the stages of the chain value (extrusion, debinding, and sintering) will be key to support the present results. Additional research into the mechanical and magnetic properties of the samples produced could lead this combination of materials to applications in various industries including automotive and aerospace.Publicationtype: Journal Article54 161