Article
Materials Science, Multidisciplinary
Biaobiao Yang, Jun Wang, Yunping Li, Matthew Barnett, Javier LLorca
Summary: A dual-textured Mg-6.5 Zn alloy with limited yield asymmetry is studied. The deformation mechanisms responsible for the behavior are analyzed and it is found that compressive deformation is accommodated by basal slip and extension twinning, while tensile deformation promotes basal and nonbasal slip. The contribution of rotated grains leads to similar values of the yield strength in tension and compression.
Article
Chemistry, Physical
Hao Zhang, Ludan Qin, Duxia Cao, Ruifang Guan, Xiao Cheng, Chuanjian Zhou
Summary: In recent years, the challenge of achieving a high quantum yield (QY) in dilute solutions of non-aromatic fluorescent materials has received widespread attention. This study successfully designed a bioinspired molecule with a dipeptide-like structure and active silanol groups, inspired by the Clustering-triggered emission (CTE) phenomenon. The hydrolysate hPDs obtained by simple heating of the bioinspired molecule can emit strong blue fluorescence in dilute solution, and this is the first time that the emission behavior of non-aromatic fluorescent materials has been realized under sunlight. The high QY of h-PDs in aqueous solution and solid state, attributed to the condensation of active silanol groups and the presence of hydrogen bonds and N-Si coordination bonds, allows small molecules to cross-link and aggregate into dense clusters.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2023)
Article
Engineering, Industrial
Madhav Baral, Ali Al-Jewad, Alexander Breunig, Peter Groche, Jinjin Ha, Yannis P. Korkolis, Brad L. Kinsey
Summary: In this study, AE sensors and DIC techniques are used to investigate the plastic deformation process of aluminum sheets. The results show that AE signals can identify and predict the location of necking and fracture.
JOURNAL OF MATERIALS PROCESSING TECHNOLOGY
(2022)
Article
Metallurgy & Metallurgical Engineering
Zhigang Li, Haifeng Yang, Jianguang Liu, Fu Liu
Summary: A novel yield criterion based on CPB06 was proposed to consider the anisotropic and tension-compression asymmetric behaviors of magnesium alloys. The criterion can predict the yield stresses and Lankford ratios under different conditions. Additionally, the proposed M_CPB06 criterion was further evolved to the M_CPB06ev model to describe the anisotropic strain-hardening characteristics. Finite element simulations conducted on specimens demonstrated the reliability and accuracy of the developed subroutine.
JOURNAL OF MAGNESIUM AND ALLOYS
(2022)
Article
Chemistry, Multidisciplinary
Charlotte Van Steen, Els Verstrynge
Summary: In this study, a hierarchical clustering algorithm based on cross-correlation was developed to automatically distinguish damage sources during the corrosion process. The algorithm was verified and found to be successful in differentiating macro-cracking from corrosion and micro-cracking at the sample scale, offering potential for assessing the extent of corrosion-induced damage.
APPLIED SCIENCES-BASEL
(2022)
Article
Chemistry, Physical
Madlen Ullmann, Christoph Kaden, Kristina Kittner, Ulrich Prahl
Summary: In this study, the orthotropic behavior of Mg-2Zn-1Al-0.3Ca (ZAX210) magnesium alloy was investigated under different temperatures. The results showed that the alloy exhibited an almost isotropic behavior and enhanced yield asymmetry, which can be attributed to the weaker basal texture developed during hot rolling and final annealing processes.
Article
Polymer Science
Michal Sofer, Pavel Sofer, Marek Pagac, Anastasia Volodarskaja, Marek Babiuch, Filip Grun
Summary: The characterisation of failure mechanisms in CFRP materials using the AE technique has been the focus of many studies. However, obtaining comprehensive and reliable information about individual failure mechanisms is challenging. In this study, tensile and compact tension tests were performed on specimens with different stacking sequences to induce specific failure modes and mechanisms. AE activity was monitored using two different wideband AE sensors and analysed using a hybrid hit detection process. The clustering analysis of the datasets revealed distinct failure mechanisms, which were confirmed by SEM analysis. Evaluation: 8 points.
Article
Chemistry, Physical
Zhen Zhang, Zhanyong Zhao, Peikang Bai, Xiaofeng Li, Bin Liu, Jibo Tan, Xinqiang Wu
Summary: The study combines electrochemical noise and acoustic emission techniques to in-situ monitor the pitting corrosion process of AZ31 magnesium alloy, successfully identifying three main corrosion stages and discussing the relationship between AE and EN parameters with different corrosion mechanisms. The main contribution is providing an effective method to monitor the self-corrosion process of Mg alloy.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Engineering, Multidisciplinary
Claudia Barile, Caterina Casavola, Giovanni Pappalettera, Vimalathithan Paramsamy Kannan
Summary: In this research, acoustic emission results from carbon fibre reinforced plastic laminates were analysed using k-means++ algorithm for clustering descriptors, with a method introduced for predicting crack length. The study also validated experimental results using analytical and finite element models.
STRUCTURAL HEALTH MONITORING-AN INTERNATIONAL JOURNAL
(2021)
Article
Engineering, Civil
M. Smolnicki, Sz. Duda, P. Stabla, P. Zielonka, G. Lesiuk
Summary: This paper presents preliminary studies on the failure analysis of hybrid composite materials using acoustic emission and machine learning. Machine learning techniques were used to better cluster the data obtained from acoustic emission. The study focused on data preparation, feature extraction, determination of cluster number, and testing three clustering techniques. The proposed method was successfully used to cluster the obtained data.
ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING
(2023)
Article
Engineering, Mechanical
Emmanuel Ramasso, Thierry Denoeux, Gael Chevallier
Summary: This paper investigates how to explicitly represent the onsets, growth, and activation levels of clusters in acoustic emission data. The authors propose a new clustering method called GMMSEQ, which provides useful qualitative information about the timeline of clusters and shows better performance in terms of cluster characterization compared to standard methods.
MECHANICAL SYSTEMS AND SIGNAL PROCESSING
(2022)
Article
Acoustics
Amos Ichenihi, Wei Li, Yantao Gao, Yunfei Rao
Summary: This study utilized acoustic emission (AE) analysis to investigate the structural behavior of hybrid composites, deriving new AE parameters and incorporating the Cronbach's alpha test for feature selection. Through this process, the constituent fiber breakage mechanisms were successfully clustered separately, along with discussions on pseudo-ductility based on the clustered AE signals. This work is crucial in evaluating hybrid composites by studying the behavior of the constituent fibers using AE analysis.
Article
Nanoscience & Nanotechnology
Z. H. Li, S. Gao, T. T. Sasaki, T. Nakata, S. Kamado, N. Tsuji, K. Hono
Summary: Clarifying the origin of the yielding phenomenon is crucial for improving the flow stability and surface finish of magnesium alloy sheet products. This study investigates the effect of Zn addition on discontinuous yielding in low-alloyed magnesium alloy sheets and reveals the significant impact of Zn on yield-drop. Transmission electron microscopy and atom probe tomography analysis demonstrate the influence of Ca-Zn co-clusters on dislocations, and different stretching directions of the sheet result in distinct Luders deformations.
SCRIPTA MATERIALIA
(2022)
Article
Automation & Control Systems
Pengjing Zhao, Jingpin Jiao, Yajun Tang, Gang Fang
Summary: The study aims to explore the feasibility of using acoustic emission and digital image correlation techniques to detect crack propagation behavior during blanking process. The results show that the combination of these two techniques provides effective information about plastic deformation and damage evolution.
INTERNATIONAL JOURNAL OF ADVANCED MANUFACTURING TECHNOLOGY
(2021)
Article
Chemistry, Physical
Laszlo Z. Toth, Lajos Daroczi, Tarek Y. Elrasasi, Dezso L. Beke
Summary: The results of acoustic emission measurements during plastic deformation of polycrystalline Sn samples are analyzed using the adaptive sequential k-means method. The acoustic avalanches are separated based on their spectral properties and presented on feature space plots and power spectral density curves. The clustering analysis is able to eliminate background noise and accurately distinguish between different acoustic emission sources.
Article
Materials Science, Multidisciplinary
Klaudia Fekete, Daria Drozdenko, Petr Cejpek, Patrik Dobron, Jozef Vesely, Michiaki Yamasaki, Yoshihito Kawamura
Summary: The study investigated the thermal stability of rapidly solidified Mg97.94Zn0.56Y1.5 alloy, finding that the material exhibits thermal stability up to 400 degrees Celsius, preventing grain growth. At higher temperatures, grain growth and texture redistribution are related to the recrystallization process. The arrangement of solute-segregated SFs is independent of annealing temperatures.
MATERIALS CHARACTERIZATION
(2022)
Article
Nanoscience & Nanotechnology
Oleksandr Boiko, Daria Drozdenko, Peter Minarik
Summary: This paper investigates the dielectric properties of (FeCoZr)(x)(Pb(ZrTi)O-3)((100-x)) granular metal-dielectric nanocomposites below the percolation threshold. Different types of polarization processes, including interfacial and dipolar polarizations, are observed. The conduction mechanism in the tested material is hopping carrier exchange between metallic phase nanograins.
Article
Crystallography
Maria Nienaber, Gerrit Kurz, Dietmar Letzig, Karl Ulrich Kainer, Jan Bohlen
Summary: The application of magnesium flat products is affected by the limited formability at room temperature and the anisotropy of the mechanical properties, which is mainly caused by the underlying hexagonal crystal structure of magnesium and the development of strong crystallographic textures during massive forming processes. This study focuses on the influence of the manufacturing process on the microstructure and texture evolution of flat products made of conventional magnesium alloy AZ31, and discusses the effects on mechanical properties and formability.
Article
Chemistry, Physical
Daria Drozdenko, Klaudia Fekete, Patrik Dobron, Gergely Nemeth, Jozef Vesely, Soya Nishimoto, Michiaki Yamasaki, Yoshihito Kawamura
Summary: This paper investigates the influence of alloying elements (Y, Gd, and Nd) on the microstructure and anisotropy of mechanical properties in Mg-Zn-based alloys prepared by the rapidly solidified ribbon consolidation technique. The material processing leads to the formation of a microstructure consisting of ultrafine dynamically recrystallized (DRX) alpha-Mg grains and worked non-DRX grains. The small average grain size and weak overall texture result in relatively high yield strength and moderate elongation during both tensile and compressive loading, with a reverse tension-compression yield asymmetry achieved in the investigated alloys.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Daria Drozdenko, Klaudia Fekete, Patrik Dobron, Michal Knapek, Kristian Mathis, Peter Minarik, Michiaki Yamasaki, Yoshihito Kawamura
Summary: The present study focuses on the yield behavior of dilute Mg-Zn-Y alloy prepared by the rapidly solidified ribbon consolidation technique. This method results in an ultrafine-grained microstructure with Zn- and Y-rich stacking faults segregated in the basal planes. Despite high yield strength and moderate elongation, a pronounced yield point phenomenon is observed during tensile loading at room temperature. Advanced image techniques and post-processing data analysis highlight the global and local microstructural changes that lead to the appearance of upper and lower yield points.
Article
Metallurgy & Metallurgical Engineering
Min Deng, Linqian Wang, Darya Snihirova, Jan Bohlen, Gerrit Kurz, Sviatlana V. Lamaka, Daniel Hoeche, Mikhail L. Zheludkevich
Summary: Thermomechanical processing can enhance the corrosion performance of lean Mg-Ca alloys, but annealing can accelerate the corrosion rate due to Fe precipitation. Micro-alloying with indium can effectively restrain the formation of Fe-containing precipitates. This finding provides a foundation for developing Mg-Ca-based alloys with high corrosion resistance, superior electrochemical performance, and excellent mechanical properties.
JOURNAL OF MAGNESIUM AND ALLOYS
(2023)
Article
Chemistry, Physical
Jan Dittrich, Gergely Farkas, Daria Drozdenko, Michal Knapek, Kristian Mathis, Peter Minarik
Summary: A combination of advanced in-situ experimental techniques, including neutron diffraction, acoustic emission, and electron backscattered diffraction, was used to investigate the deformation behavior of magnesium alloys. The potential and limitations of these techniques were demonstrated in a study on the influence of crystallographic texture on deformation mechanisms in a hot-rolled sheet of the AZ31 alloy. The results showed the twinning activity and its evolution, as well as the deformed microstructure, providing valuable insights into the deformation mechanisms of the alloy.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Michaela Slapakova, Barbora Kihoulou, Jozef Vesely, Peter Minarik, Klaudia Fekete, Michal Knapek, Rostislav Kralik, Olexandr Grydin, Mykhailo Stolbchenko, Mirko Schaper
Summary: This paper reveals the 3D character of the intermetallic layer at the aluminum-steel interface during annealing. The presence of the intermetallics was confirmed using atomic force microscopy and the chemical composition of the surface layer was found to be the same as the bulk interface. The growth direction of the intermetallic phase is towards both aluminum and steel, with a higher diffusion flux from aluminum towards steel.
Article
Chemistry, Physical
Soroush Najafi, Alireza Sheikhani, Mahdi Sabbaghian, Peter Nagy, Klaudia Fekete, Jeno Gubicza
Summary: The influence of rare earth (RE) elements on the microstructure and mechanical performance of an extruded ZK60 Mg alloy was investigated. The addition of Y and Ce-rich RE elements resulted in finer grain size, the formation of new precipitates, and changes in the initial fiber texture. As a result, the strength increased and the ductility decreased. The work hardening capacity and the hardening exponent of the alloy were reduced due to grain refinement.
Article
Chemistry, Physical
Gerrit Kurz, Ketan Ganne, Maria Nienaber, Jan Bohlen
Summary: Rare earth elements improve the properties of magnesium sheets, while Mn as an alloying element increases the strength of Mg-Zn-Ca alloy. This study investigates the influence of Mn on the process parameters during rolling and heat treatment of a Mg-Zn-Mn-Ca alloy. The microstructure, texture, and mechanical properties of the alloy are compared after rolling and heat treatment at different temperatures.
Article
Metallurgy & Metallurgical Engineering
Maria Zemkova, Peter Minarik, Jan Dittrich, Jan Bohlen, Robert Kral
Summary: This study investigated the effect of yttrium and neodymium alloying on microstructure formation during severe plastic deformation and its impact on the mechanical and corrosion properties of binary Mg-3Y and Mg-3Nd alloys. The presence of Nd primarily caused precipitation, while Y remained dissolved in the magnesium matrix. The ECAP-processed W3 sample exhibited a combination of ultrafine-grain structure, weak crystallographic texture, high strength, and high corrosion resistance.
JOURNAL OF MAGNESIUM AND ALLOYS
(2023)
Article
Chemistry, Physical
Kristian Mathis, Andrea Farkas, Michal Knapek, Andriy Ostapovets, Gergely Farkas, Gergely Nemeth, Petr Harcuba, Daria Drozdenko
Summary: Ultra-high-speed camera (UHSC) imaging was used to study how the gadolinium (Gd) content affects the longitudinal growth of twins in Mg-Gd binary alloys. The results showed that the twin propagation rate is approximately 101 m/s and decreases with increasing Gd concentration. Concurrent molecular dynamics (MD) simulations revealed that the presence of Gd atoms promotes the formation of stacking faults (SFs), which hinder twin propagation as effectively as twin boundary pinning by Gd solutes. Consequently, the twin tip exhibits intermittent motion at the microscopic level.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Multidisciplinary
Dalibor Preisler, Michal Knapek, Petr Harcuba, Josef Strasky, Tomas Charska
Summary: Acoustic emission and digital image correlation (DIC) were utilized to determine mechanical properties of six biomedical alloys during a compression deformation experiment. The layered sample of six Ti-(20-35)Nb-7Zr0.2O alloys was prepared using spark plasma sintering, and DIC was used to separate the deformation in each layer and determine the flow curve of each alloy. Simultaneously, acoustic emission provided insights into the active plastic deformation mechanisms, indicating the effect of Nb content on ductility and compression flow curve shape.
Article
Thermodynamics
Tomas Hulan, Igor Stubna, Tiit Kaljuvee, Michal Knapek
Summary: This study investigated cracking in traditional ceramics caused by quartz transitions, focusing on the temperature region around 570 degrees C. The research found a local minimum of Young's modulus (YM) during quartz transition, which was more pronounced at higher firing temperatures with a higher glassy phase fraction. Strong correlation between YM and acoustic emission (AE) provided evidence of cracking. Hysteresis in YM during heating and cooling indicated a reversible quartz transition, suggesting that microcracks significantly influence the overall properties of the ceramics.
JOURNAL OF THERMAL ANALYSIS AND CALORIMETRY
(2022)