Article
Engineering, Mechanical
Guocai Chai, Jens Bergstrom, Christer Burman
Summary: In this study, the formation of FGA in a non-defect matrix of austenitic steel during very high cycle fatigue was investigated using a stepwise load-increasing method and ECCI technique. A new phenomenon of nano rough surface or FGA at the fatigue crack origin was observed in the subsurface matrix without any defect. A mechanism based on the dislocation plasticity theory was proposed, suggesting that FGA formation is a localized plasticity exhausting process. This research is of great importance for understanding the mechanism of FGA formation and fatigue fracture in materials.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2023)
Article
Materials Science, Multidisciplinary
Xiangnan Pan, Leiming Du, Guian Qian, Youshi Hong
Summary: This study investigates the behavior of very-high-cycle fatigue (VHCF) in metallic materials such as aluminum alloys and high-strength steels. The research reveals that in additively manufactured AlSi10Mg alloy, crack initiation and growth mechanisms are distinct from those in high-strength steels, but demonstrate a similar characteristic region of crack initiation known as fine granular area (FGA).
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2024)
Article
Engineering, Mechanical
Z. M. Jian, G. A. Qian, D. S. Paolino, A. Tridello, F. Berto, Y. S. Hong
Summary: The study revealed that AlSi10Mg specimens printed with 50μm powder size exhibit higher fatigue properties compared to those printed with 20μm powder size, with unmelted powders being the main source of crack initiation. Additionally, specimens printed with 50μm powder size are more prone to subsurface crack initiation in the VHCF regime, with five different crack initiation modes identified and fatigue strength assessed by statistical model.
INTERNATIONAL JOURNAL OF FATIGUE
(2021)
Article
Materials Science, Multidisciplinary
Fulin Liu, Yao Chen, Lang Li, Chong Wang, Qingyuan Wang, Yongjie Liu
Summary: The interior defect-induced crack initiation mechanism and early growth behavior of Ti6Al4V alloy fabricated by laser powder bed fusion (LPBF) have been investigated in the very high cycle fatigue (VHCF) regime. The findings show that the formation of fine granular area (FGA) is composed of discontinuous nanograins, which are associated with dislocation movement and grain boundaries. Additionally, the fatigue loading process and the LPBF process contribute to the development of microvoids, accelerating the extension of microcracks.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Nanoscience & Nanotechnology
Esmaeil Sadeghi, Gbenga Asala, Paria Karimi, Dunyong Deng, Johan Moverare, Thomas Hansson
Summary: A unique melting strategy was implemented in EB-PBF of Alloy 718, resulting in the formation of a bimodal grain morphology consisting of fine equiaxed and columnar grains. The microstructure was preserved following various thermal post-treatments. Clustered inclusions acted as the crack initiation site, reducing the specimens' total fatigue life. Intergranular fracture mode was favored in the plastic zone ahead of the crack tip.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Robert Otto, Vegard Brotan, Patricia A. Carvalho, Magnus Reiersen, Joachim S. Graff, Martin F. Sunding, Olav Asebo Berg, Spyros Diplas, Amin S. Azar
Summary: Introducing a new alloy for additive manufacturing requires iterative builds to avoid micro-cracks.
MATERIALS & DESIGN
(2021)
Article
Chemistry, Physical
Carsten Wickmann, Christopher Benz, Horst Heyer, Kerstin Witte-Bodnar, Jan Schaefer, Manuela Sander
Summary: This study aimed to investigate the formation of the 'fine granular area' (FGA) in additively manufactured Ti6Al4V specimens with artificially generated internal defects in the early stage of fatigue crack growth in the 'very high cycle fatigue' (VHCF) regime. Fatigue tests were conducted using an ultrasonic fatigue testing setup, and failed specimens were analyzed using optical microscopy, scanning electron microscopy (SEM), and focused ion beam (FIB) techniques. Alternative proposals for identifying the FGA layer were introduced, and various fracture mechanical approaches were applied to evaluate the possibility of FGA formation, with results compared to experimental findings.
Article
Materials Science, Multidisciplinary
Reza Ghanavati, Erika Lannunziata, Ehsan Norouzi, Sara Bagherifard, Luca Iuliano, Abdollah Saboori
Summary: This study investigated the capability of the standard laser powder bed fusion process to produce SS316L-IN718 functionally graded materials with different designs. The analysis and discussion revealed the gradual evolution of the solidification structure, smooth distribution of constituent elements, and orientation and grain growth in the build direction. The gradient design with a 50 wt% mixed intermediate zone and optimum processing condition showed the best mechanical properties.
Article
Materials Science, Multidisciplinary
D. Riabov, K. Frisk, M. Thuvander, E. Hryha, S. Bengtsson
Summary: This study introduces a new Co-free stainless maraging alloy developed for laser-based powder bed fusion, showcasing excellent printability and low porosity levels. The precipitation strengthening response was evaluated through aging and various precipitates with excellent hardness and strength were observed.
MATERIALS & DESIGN
(2022)
Article
Optics
Tamas Markovits, Ferenc Laszlo Varga
Summary: This research investigates the connection between supports and metal parts in additive manufacturing, examining the impact on mechanical fixturing, heat conduction, removability of supports, and printing success. The study explores various support and tooth parameters to create a strength map for the model-support connection. Shearing properties are characterized using a torsion test, comparing results for different support parameters and materials.
OPTICS AND LASER TECHNOLOGY
(2022)
Article
Engineering, Mechanical
Xue Li, Chao He, Xiangyu Wang, Yao Chen, Chong Wang, Hong Zhang, Lang Li, Yongjie Liu, Qingyuan Wang
Summary: This study investigated the behavior and crack initiation mechanism of super martensitic stainless steel under very-high-cycle fatigue at elevated temperature. The cracks in this condition initiated from the surface and formed a fine granular area. This area consisted of an initiation site, a smooth region, and an annular continuous fine granular area. The fine granular area formed in the peaks and valleys of local microstructures, while the smooth regions connected these peaks and valleys dominated by shear stress.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2023)
Article
Chemistry, Multidisciplinary
Achille Gazzerro, Wilma Polini, Luca Sorrentino, Gillo Giuliano
Summary: Powder Bed Fusion (PBF) is a popular additive manufacturing technology known for its high build resolution and capability to produce microscale geometries without additional support. However, the aging of PA12 powder, which is used as support material, diminishes the mechanical properties of the built parts. This study aims to characterize powder aging through experimental tests and utilize the findings in a simulation software to optimize the process.
APPLIED SCIENCES-BASEL
(2023)
Article
Engineering, Mechanical
Arash Soltani-Tehrani, John P. Isaac, Hareesh Tippur, Daniel F. Silva, Shuai Shao, Nima Shamsaei
Summary: This study investigated the effects of powder reuse and location dependency on the mechanical properties of laser powder bed fused Ti-6Al-4V Grade 5 parts. The results showed that reusing the powder improved powder flowability and packing state, but increased oxygen content. Powder reuse increased tensile strength and critical energy release rate under high strain-rate loading, but specimens in downstream locations suffered from spattering, resulting in lower fatigue performance and tensile ductility.
INTERNATIONAL JOURNAL OF FATIGUE
(2023)
Review
Engineering, Manufacturing
H. R. Kotadia, G. Gibbons, A. Das, P. D. Howes
Summary: Additive manufacturing of metallic alloys has gained significant interest in the past two decades, particularly in aerospace and automotive applications. However, the development of AM with Al-alloys has been slow, with current research focusing on AlSiMg-based alloys and AlMgSc alloys, facing challenges and obstacles.
ADDITIVE MANUFACTURING
(2021)
Article
Materials Science, Multidisciplinary
A. Luddecke, O. Pannitz, H. Zetzener, J. T. Sehrt, A. Kwade
Summary: Coating metal alloy powders with nanoparticles can improve additive manufacturing processes and enhance material quality and energy absorption. The coating process conducted within a fluidized bed system results in homogeneous coatings, showing potential to improve performance of commercial AM powders.
MATERIALS & DESIGN
(2021)
Article
Chemistry, Physical
Hassaan A. Butt, Ilya V. Novikov, Dmitry V. Krasnikov, Artem V. Sulimov, Amit K. Pal, Stanislav A. Evlashin, Anton M. Vorobei, Yaroslav I. Zuev, Dmitry Ostrizhiniy, Dmitry Dzhurinskiy, Yuri A. Popov, Olga O. Parenago, Albert G. Nasibulin
Summary: In this work, pre-consolidated form of single-walled carbon nanotubes (SWCNT) - SWCNT briquettes - are proposed as a material for manufacturing electrically and thermally conductive thermoset nanocomposites. The briquettes provide similar performance to other forms of SWCNTs in the nanocomposites, with low percolation thresholds. Compared to other forms of SWCNTs, the pre-consolidated briquettes have lower cost and better dispersibility, making them suitable for large scale production and small scale laboratories.
Article
Biochemical Research Methods
Nataliya R. Rovnyagina, Gleb S. Budylin, Pavel Dyakonov, Yuri M. Efremov, Marina M. Lipina, Yuliya R. Goncharuk, Emirkhan E. Murdalov, David A. Pogosyan, Denis A. Davydov, Alexander A. Korneev, Natalia B. Serejnikova, Karen A. Mikaelyan, Stanislav A. Evlashin, Vladimir A. Lazarev, Alexey Lychagin, Peter S. Timashev, Evgeny A. Shirshin
Summary: This study utilized diffuse reflectance spectroscopy in the NIR range to detect early stages of osteoarthritis and assess the damage grades and mechanical properties of cartilage.
JOURNAL OF BIOPHOTONICS
(2023)
Article
Materials Science, Multidisciplinary
R. Mendagaliev, D. D. Evdokimov, A. M. Firsov, A. M. Vildanov, A. D. Evstifeev, V. Maksimochkin, R. A. Grachev, O. N. Dubinin, S. A. Evlashin, O. G. Klimova-Korsmik
Summary: Gradient materials have significant practical importance in machinery and aviation. This article demonstrates a fabrication strategy for novel steel-steel metamaterials with different microhardness and magnetic properties, using additive manufacturing technology.
METALS AND MATERIALS INTERNATIONAL
(2023)
Article
Automation & Control Systems
Marina O. Gushchina, Yulia O. Kuzminova, Oleg N. Dubinin, Stanislav A. Evlashin, Arthur M. Vildanov, Olga G. Klimova-Korsmik, Gleb A. Turichin
Summary: In this study, a multilayer titanium composite was produced using laser direct energy deposition, showing improved mechanical properties and impact toughness. This development has practical significance for the advancement of new materials.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2023)
Article
Materials Science, Multidisciplinary
Yifan Zhao, Qiang Liu, Ran Li, Stepan Lomov, Sergey G. Abaimov, Ke Xiong, Hanqi Zhang, Changhao Chen, Qi Wu
Summary: In this study, a novel composite was developed using carbon nanotube film and glass fiber-reinforced thermoplastic. This smart composite demonstrated self-sensing and self-healing capabilities for damage caused by low-energy impacts. The discontinuation of the conductive path of carbon nanotubes resulted in internal damage, which was repaired through the Joule heat effect, achieving a self-healing efficiency of 87% in terms of flexural strength.
JOURNAL OF INTELLIGENT MATERIAL SYSTEMS AND STRUCTURES
(2023)
Article
Polymer Science
Milad Jafarypouria, Biltu Mahato, Sergey G. Abaimov
Summary: The study shows that the curing state of the polymer matrix significantly influences the temperature coefficient of resistance (TCR) of a single-walled carbon nanotube/epoxy polymer nanocomposite. Uncertainty in the degree of cure leads to biased TCR measurements, and only when the material reaches its steady state, the TCR values become unbiased and show a steady, monotonic increase from near zero at room temperature to 0.001 1/°C at 100°C.
Article
Polymer Science
Stepan V. V. Lomov, Iskander S. S. Akmanov, Qiang Liu, Qi Wu, Sergey G. G. Abaimov
Summary: The temperature dependence of the electrical conductivity/resistivity of CNT networks is observed to be negative, especially for aligned CNTs (A-CNTs). This study investigates the role of three phenomena, namely the temperature dependence of the intrinsic conductivity of CNTs, the tunnelling resistance of their contacts, and thermal expansion of the network, on the temperature coefficient of resistance (TCR). The results show that the TCR of the CNTs themselves is the main factor influencing the TCR of the film, while the TCR of the tunnelling contacts and film thermal expansion have marginal effects.
Article
Engineering, Manufacturing
E. Syerko, T. Schmidt, D. May, C. Binetruy, S. G. Advani, S. Lomov, L. Silva, S. Abaimov, N. Aissa, I. Akhatov, M. Ali, N. Asiaban, G. Broggi, J. Bruchon, B. Caglar, H. Digonnet, J. Dittmann, S. Drapier, A. Endruweit, A. Guilloux, R. Kandinskii, A. Leygue, B. Mahato, P. Martinez-Lera, M. Matveev, V. Michaud, P. Middendorf, N. Moulin, L. Orgeas, C. H. Park, S. Rief, M. Rouhi, I. Sergeichev, M. Shakoor, O. Shishkina, Y. Swolfs, M. Tahani, R. Umer, K. Vanclooster, R. Vorobyev
Summary: This paper presents the results of an international virtual permeability benchmark, which is a first contribution to permeability predictions for fibrous reinforcements based on real images. In this first stage, the focus was on the microscale computation of fiber bundle permeability. The scatter of the predicted axial permeability after the elimination of inconsistent results was found to be smaller (14%) than that of the transverse permeability (similar to 24%).
COMPOSITES PART A-APPLIED SCIENCE AND MANUFACTURING
(2023)
Article
Biochemistry & Molecular Biology
Yuliya Kan, Julia V. Bondareva, Eugene S. Statnik, Elizaveta V. Koudan, Evgeniy V. Ippolitov, Mikhail S. Podporin, Polina A. Kovaleva, Roman R. Kapaev, Alexandra M. Gordeeva, Julijana Cvjetinovic, Dmitry A. Gorin, Stanislav A. Evlashin, Alexey I. Salimon, Fedor S. Senatov, Alexander M. Korsunsky
Summary: The study investigates the interaction and functionality of hydrophilic nanofibers for antibacterial wound coatings. Coaxial electrospinning is used to create a core-shell fiber composite with polyvinyl alcohol, polyethylene glycol, amorphous silica (PVA-PEG-SiO2) in the core, and polyvinyl alcohol, graphene oxide (PVA-GO) in the shell. Crosslinking with graphene oxide and silica enables the fiber composite to transition into a hydrogel upon contact with moisture, optimizing drug release. The CHX medicated core-shell composite exhibits sustained antibacterial activity against Staphylococcus aureus.
INTERNATIONAL JOURNAL OF MOLECULAR SCIENCES
(2023)
Review
Polymer Science
Aleksei V. V. Shiverskii, Mohammad Owais, Biltu Mahato, Sergey G. G. Abaimov
Summary: The problem of icing on engineering structures is becoming increasingly important due to active industrialization in permafrost zones, new goals in Arctic marine transport, increasing requirements for aerodynamically critical surfaces, and the wide applicability of fiber-reinforced polymer composites. Traditional manufacturing approaches are being combined with new technologies such as 3D printers and robotics for laying heat wires, and cheap and high-performance Thermal Sprayed methods for metallic cover manufacturing. The next step in developing heaters for polymer structures is the use of nano and micro additives to create electrically conductive heating networks.
Review
Polymer Science
Biltu Mahato, Stepan V. Lomov, Aleksei Shiverskii, Mohammad Owais, Sergey G. Abaimov
Summary: This paper provides an overview of the application of nanofiber polymeric veils as toughening interleaves in fiber-reinforced composite laminates. It presents a comparative analysis and summary of attainable fracture toughness improvements based on electrospun veil materials. The toughening mechanisms introduced by polymeric veils are identified, listed, and analyzed, and the numerical modeling of failure in Mode I and Mode II delamination is discussed.
Article
Engineering, Multidisciplinary
Alexey A. Pcheliakov, Ekaterina Yu. Diachkova, Yuriy L. Vasil'ev, Oxana A. Svitich, Alexander V. Poddubikov, Stanislav A. Evlashin, Beatrice A. Volel, Anastasia A. Bakhmet, Svetlana V. Klochkova, Ellina V. Velichko, Natalia Tiunova, Svetlana V. Tarasenko
Summary: The purpose of this study was to compare the mechanical properties and microbiological resistance of mono- and polyfilament suture materials used in tooth extraction operations. Results showed that monofilament suture materials performed better in all experiments and absorbed fewer bacteria compared to polyfilament sutures. Prolene monofilament suture material had the best microbiological resistance and good mechanical properties.
Article
Mechanics
S. I. Ashitkov, P. S. Komarov, S. A. Romashevskiy, E. V. Struleva, S. A. Evlashin
Summary: This study investigates laser-driven shock wave phenomena in a sub-micrometer Mg-4Al-2Zn alloy film using spectral interferometry. The experimental findings are important for predicting the behavior of magnesium alloys at high strain rates, studying the physics of metastable states, and simulating the interaction of laser pulses with thin film materials.
Article
Materials Science, Multidisciplinary
Yulia O. Kuzminova, Denis G. Firsov, Anastasia A. Shibalova, Egor A. Kudryavtsev, Pavel Krakhmalev, Olga G. Klimova-Korsmik, Igor V. Shishkovsky, Stanislav A. Evlashin
Summary: High-entropy Alloys (HEAs) are promising materials for harsh conditions and additive manufacturing (AM) can be used for adjusting their composition. In this study, CrFeCoNi(Al,Ti) HEAs were printed by powder bed fusion (PBF) using a blend of three powders. The investigation revealed chemical inhomogeneity and phase formations in the printed alloys, which can be influenced by post-treatment processes such as high-temperature annealing.
Article
Materials Science, Multidisciplinary
Stanislav A. Evlashin, Yulia O. Kuzminova, Alexey P. Simonov, Denis G. Firsov, Oleg N. Dubinin, Oleg A. Rogozin, Mikhail V. Perevozchikov, Iskander S. Akhatov
Summary: Laser powder bed fusion technology allows for the production of complex shapes in various alloys and the manipulation of material composition to improve properties. By adding boron, the microhardness and ultimate tensile strength of 316L stainless steel can be significantly improved, making it suitable for tool printing.
