Article
Nanoscience & Nanotechnology
Dhrubjyoti Baruah, S. Arjun Sreedhar, Saurabh Kumar Gupta, Satyam Suwas, R. Narasimhan
Summary: This study investigates the effect of temperature on the mixed-mode fracture response of a rolled AZ31 Mg alloy. Experimental results show that the fracture toughness Jc enhances by a factor of about 3.5, irrespective of mode mixity over the temperature range studied. The change in fracture mechanism from brittle cracking to ductile void growth and coalescence is observed as the temperature increases.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Mechanics
D. Santos, A. Akhavan-Safar, R. J. C. Carbas, E. A. S. Marques, S. Wenig, L. F. M. da Silva
Summary: The rate of fatigue crack growth and fatigue threshold energy release rate are crucial parameters for designing adhesive joints for fatigue service. Different testing strategies, constant load control and constant displacement control, can be used to obtain these parameters through fatigue fracture tests. The effect of testing methodology and temperature on the fatigue behavior of adhesives was investigated for a structural polyurethane adhesive used in automotive applications.
ENGINEERING FRACTURE MECHANICS
(2023)
Article
Materials Science, Multidisciplinary
Arjun Sreedhar, Suraj Ravindran, Gyan Shankar, S. Suwas, R. Narasimhan
Summary: Static and dynamic fracture experiments on rolled AZ31 Mg alloy revealed different fracture mechanisms under different loading conditions, with an increase in twin density and associated texture under dynamic loading, leading to a significant increase in fracture toughness at high loading rates.
Article
Nanoscience & Nanotechnology
W. J. Wu, W. Z. Chen, L. X. Zhang, X. M. Chen, H. X. Wang, W. K. Wang, W. C. Zhang
Summary: The study successfully prepared high-strength ZK61 magnesium alloy rods with tension/compression symmetry using the upsetting-extrusion process. By analyzing the microstructure evolution, it was found that lowering temperature and increasing upsetting ratio had positive effects on microstructure refinement. The relationship between microstructure and tension/compression yield strengths was also discussed, showing the importance of texture-dependent mechanisms in deformation processes.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Engineering, Mechanical
Monika Duda, Dariusz Rozumek, Michal Smolnicki, Anna Wybraniec
Summary: The article discusses the results of a study on fatigue fracture in mixed and I + II and I + III modes in heat treated steel 42CrMo4. It presents different mechanical properties resulting from various thermal treatments and demonstrates tests conducted on different sample types and load angles. The research aims to enhance understanding of fatigue crack development under mixed modes and provide valuable insights into the material's behavior under complex loads.
INTERNATIONAL JOURNAL OF FATIGUE
(2022)
Article
Metallurgy & Metallurgical Engineering
Jong Un Lee, Gyo Myeong Lee, Sung Hyuk Park
Summary: Precompression and subsequent annealing treatment can improve the bending formability of the Mg-9Al-1Zn-0.3Mn-0.9Ca-0.6Y alloy. The PCAed material exhibits higher bending formability due to the promoted twinning and slip behaviors.
JOURNAL OF MAGNESIUM AND ALLOYS
(2022)
Article
Materials Science, Multidisciplinary
T. Nakata, C. Xu, S. Kamado
Summary: After cold-rolling an Mg-6Zn-0.3Ca alloy sheet with a strong basal texture, anomalous double twinning occurred with the (0001) pole aligned to the transverse direction. These twins served as nucleation sites for statically recrystallized grains during annealing, resulting in weak texture features in the annealed sheet with transverse-direction split (0001) poles.
MATERIALS CHARACTERIZATION
(2021)
Article
Materials Science, Multidisciplinary
S. Arjun Sreedhar, Dhrubjyoti Baruah, Gyan Shankar, Satyam Suwas, R. Narasimhan
Summary: This study investigates the fracture behavior of AZ31 Mg alloy at different temperatures. Experimental results show that the fracture mechanism changes from brittle cracking to ductile void growth as temperature increases. Increased temperature also leads to increased twinning and texture changes in the far-edge of the ligament.
INTERNATIONAL JOURNAL OF FRACTURE
(2022)
Article
Materials Science, Multidisciplinary
Jie-Wen Zhang, Jia-Xiang Wang, Xiao-Wei Zou, Irene J. Beyerlein, Wei-Zhong Han
Summary: This study investigates the strengthening of interface-dominate properties at nanoscale dimensions. Through the analysis of alpha-Zr sandwiched by alpha/beta interfaces, it is found that the refinement of alpha/beta lamellar structures significantly enhances the formability of the Zr-2.5Nb alloy. High density alpha/beta interfaces are found to enhance the activity of dislocations and deformation twins, ultimately increasing the formability of the alloy.
Article
Nanoscience & Nanotechnology
T. Nakata, C. Xu, L. Geng, S. Kamado
Summary: We report the formation of an unusual texture on the sheet-surface of a rolled Mg-3Al-0.4Mn alloy, where a typical basal texture is formed at the center of the sheet and an unusual texture with vertical tiling is observed at the sheet-surface. The surface promotes prismatic slips and dynamic recrystallization, leading to a high fraction of fine basal-textured grains and a small fraction of off-basal-textured grains. In contrast, the center preserves a relatively high fraction of deformed grains, promoting the growth of basal-textured grains and the formation of the typical basal texture.
SCRIPTA MATERIALIA
(2023)
Article
Chemistry, Physical
T. Nakata, C. Xu, L. Geng, S. Kamado
Summary: This paper reports the application of cold-sample rolling (CSR) processing in a Mg-6Al-1Zn alloy sheet, which resulted in a high fraction of double twins and a substantial texture-weakening effect. Compared to high-temperature rolling (HTR) processing, CSR processing induced a relatively higher texture-weakening effect. The results indicate that twinning-mediated static recrystallization is essential for texture weakening in Al-concentrated Mg-alloy sheets.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Mechanics
Shiv Sahaya Shukla, S. Sajith, K. S. R. K. Murthy
Summary: A simple and efficient specimen geometry for mixed mode (I/II) fracture tests and fatigue crack growth studies has been proposed in this investigation. Through extensive finite element analyses and experimental studies, the proposed specimen geometry shows good agreement with widely used fracture criteria in terms of fracture toughness, indicating its practicality.
EUROPEAN JOURNAL OF MECHANICS A-SOLIDS
(2022)
Article
Materials Science, Multidisciplinary
Yuncheng Li, Hongxian Xie, Dong Zhen
Summary: The effect of orientation on the twin formation mechanism of body-centered cubic tungsten nanopillars was investigated using molecular dynamics simulation. The simulation results showed that different orientations lead to different dominant modes of twinning or anti-twinning under tension or compression, which were explained in terms of the Schmid factor and energy.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Metallurgy & Metallurgical Engineering
T. Nakata, C. Xu, L. Geng, S. Kamado
Summary: This study investigates the origin of the unique parallel alignment of (0001) poles to the transverse direction in rolled alloy sheets. It is found that intermediate reheating during rolling facilitates static recrystallization and leads to the formation of the parallel alignment of (0001) poles to the transverse direction. In contrast, continuous rolling without intermediate reheating suppresses the formation of the unique alignment. The presence of severely deformed regions near double twins hinders the nucleation and growth of statically recrystallized grains, resulting in in-plane anisotropy in ductility.
JOURNAL OF MAGNESIUM AND ALLOYS
(2023)
Review
Metallurgy & Metallurgical Engineering
Ehsan Gerashi, Reza Alizadeh, Terence G. Langdon
Summary: Magnesium and its alloys are lightweight and potential bioresorbable materials, but their corrosion resistance is poor. This review summarizes the effects of crystallographic texture and twinning on the corrosion behavior of magnesium and its alloys, revealing contradictory results.
JOURNAL OF MAGNESIUM AND ALLOYS
(2022)
Article
Nanoscience & Nanotechnology
E. Polatidis, G. N. Haidemenopoulos, D. Krizan, N. Aravas, T. Panzner, M. Smid, I. Papadioti, N. Casati, S. Van Petegem, H. Van Swygenhoven
Summary: The study found that stress triaxiality is not the sole factor influencing the evolution of deformation-induced martensite, and there are significant differences in transformation kinetics under different loading states. The stability and size of austenite particles play a crucial role in the austenite phase transformation.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Engineering, Mechanical
Christos G. Prosgolitis, Alexis T. Kermanidis, Helen Kamoutsi, Gregory N. Haidemenopoulos, Spyros A. Karamanos
Summary: Cold forming causes significant plastic deformation at corner locations of structural steel members, affecting the fatigue resistance of the steel. Pre-existing plastic deformation influences material behavior, with prestrained materials showing higher fatigue crack growth rates in the low Δκ region compared to reference materials. Additionally, S460MC steel exhibits higher crack growth rates than S355MC steel within the examined Δκ range.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2021)
Review
Materials Science, Multidisciplinary
Shaima H. Albedwawi, Asala AlJaberi, Gregory N. Haidemenopoulos, Kyriaki Polychronopoulou
Summary: This review highlights the great potential of high entropy oxides (HEO) as promising catalysts compared to conventional metal oxides, emphasizing their superior properties in terms of oxygen activity, oxygen vacancy quantity, and metal dispersion.
MATERIALS & DESIGN
(2021)
Article
Nanoscience & Nanotechnology
Maria-Ioanna T. Tzini, John S. Aristeidakis, Peter Christodoulou, Alexis T. Kermanidis, Gregory N. Haidemenopoulos, Daniel Krizan
Summary: Austenite stability and dispersion are key parameters controlling the strain-induced transformation in TRIP steels. This study presents an integrated approach using multi-phase field modeling to describe the microstructural evolution of TRIP700 steel. By considering the local properties of retained austenite (RA), it was found that refined RA is more stable and transforms into martensite at a later stage of deformation. The simulations were validated against experiments conducted on TRIP700 steel, showing good agreement. This integrated approach can assist in designing optimal microstructural characteristics for TRIP steels.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Konstantinos Tserpes, Panagiotis Bazios, Spiros G. Pantelakis, Maria Pappa, Nikolaos Michailidis
Summary: This study developed a numerical model to simulate nanoindentation tests and converted the numerical results into stress-strain curves to obtain macroscopic mechanical properties. The validation showed good agreement between the numerical nanoindentation results and experimental results. The study found that porosity is a crucial parameter that needs to be considered in multiscale numerical methodologies.
Article
Materials Science, Multidisciplinary
John S. S. Aristeidakis, Gregory N. N. Haidemenopoulos
Summary: In this study, a physically based constitutive and transformation kinetics model is presented to describe the formation of stress-assisted and strain-induced martensite and twin in steels containing austenite. The deformation behavior of different phases is modeled using dislocation density, and the macroscopic response of the material is calculated using a homogenization method. The model predicts the fractions of different martensite and twin phases and can be used in the design of new alloys with exceptional properties.
Article
Materials Science, Multidisciplinary
Gulsah Aktas Celik, S. Hakan Atapek, Seyda Polat, Maria-Ioanna T. Tzini, Gregory N. Haidemenopoulos
Summary: This study investigates the high-temperature oxidation behavior of ductile cast irons designed with the addition of Nb and Al. The results show that the designed alloys exhibit better oxidation resistance at elevated temperatures compared to commercial SiMo alloy, and the performance is further enhanced with increased aluminum content.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2022)
Review
Engineering, Manufacturing
N. Ahmed, I. Barsoum, G. Haidemenopoulos, R. K. Abu Al-Rub
Summary: This paper reviews the research on L-PBF process parameter optimization for 316L steel components, including methods to maximize part density and achieve desired microstructure morphology, and introduces the research on numerical simulation approach for high density process parameter optimization.
JOURNAL OF MANUFACTURING PROCESSES
(2022)
Article
Chemistry, Physical
Christos G. Prosgolitis, Alexis T. Kermanidis, Helen Kamoutsi, Gregory N. Haidemenopoulos
Summary: The plastic deformation during cold roll forming can affect the fatigue performance of lightweight steel profiles, resulting in decreased fatigue resistance and ductility, as well as cyclic softening. Plastic pre-straining also reduces the transition life and fracture section of the materials.
Article
Chemistry, Physical
Helen Kamoutsi, Gregory N. Haidemenopoulos, Anette E. E. Gunnaes, Spyros Diplas
Summary: Wrought magnesium alloys have poor corrosion resistance, but the addition of rare earth elements can enhance their resistance. The WE-43 alloy, containing Nd and Y, showed better corrosion resistance compared to AZ31 and AZ61 alloys. This was due to the presence of anodic sites and the incorporation of Y in the oxide/hydroxide film.
Article
Engineering, Aerospace
Christos V. Katsiropoulos, Spiros G. Pantelakis, Marco Barile, Leonardo Lecce
Summary: A novel hybrid thermoplastic prepreg material has been developed for the fabrication of next-generation recyclable composite aerostructures using automated technologies, showing excellent processability and strength. The potential of the new material for aircraft structural parts manufacturing was demonstrated by producing a typical aeronautical flat skin panel through autoclave-based process. A newly developed holistic index was utilized for a comprehensive comparison of materials, revealing clear cost and environmental advantages of the hybrid thermoplastic material in industrial manufacturing of structural components.
Article
Engineering, Manufacturing
Dionysios N. Markatos, Christos V. Katsiropoulos, Konstantinos I. Tserpes, Spiros G. Pantelakis
Summary: A comprehensive End-of-Life (EoL) Index is introduced in this study as a decision support tool for selecting the optimal recycling process for CFRP waste, taking into account the quality, cost, and environmental impact of the recycling methods considered. This Index quantifies the reusability potential of the recycled fibers and offers an estimated balanced score that reflects the trade-off between this potential and the cost and environmental impact of the recycling methods.
MANUFACTURING REVIEW
(2021)
Article
Metallurgy & Metallurgical Engineering
G. A. Celik, M- Tzini, S. Polat, J. Aristeidakis, S. H. Atapek, P. Sarafoglou, G. N. Haidemenopoulos
Summary: The study investigates the solidification process and microstructural features of Si-Mo ductile iron through thermodynamic and kinetic calculations, thermal analysis, and microanalysis. It was found that heat treatment is needed to improve the mechanical properties of the cast matrix.
JOURNAL OF MINING AND METALLURGY SECTION B-METALLURGY
(2021)
