Article
Materials Science, Multidisciplinary
Y. Ge, M. Vronka, P. Vertat, M. Karlik, S. P. Hannula, O. Heczko
Summary: Three possible twinning modes and corresponding twin boundaries in 2H martensite of Cu 69.4 Ni 3.4 Al 27.2 single crystal were studied. The results show that these twin boundaries have differences and are closely related to twinning stress or twin-boundary mobility.
Article
Nanoscience & Nanotechnology
Shaohui Li, Daoyong Cong, Wenxin Xiong, Zhen Chen, Xin Zhang, Zhihua Nie, Shengwei Li, Runguang Li, Youkang Wang, Yuxian Cao, Yang Ren, Yandong Wang
Summary: In this study, a low-cost high-performance polycrystalline high-temperature shape memory alloy with extraordinary high-temperature superelasticity and a giant two-way shape memory effect has been developed. This alloy has the highest recoverable strain of superelasticity and two-way shape memory strain among bulk polycrystalline HTSMAs, showing great potential for high-temperature shape memory applications.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Metallurgy & Metallurgical Engineering
Zhang Xin, Cui Bo, Sun Bin, Zhao Xu, Zhang Xin, Liu Qingsuo, Dong Zhizhong
Summary: In this study, the physical and mechanical properties, as well as corrosion behavior, of Cu-Al-Ni alloys doped with Y element were investigated. It was found that the addition of Y improved the mechanical properties of the alloys and influenced their microstructure. Additionally, the corrosion behavior of the alloys was slightly reduced with Y addition.
ACTA METALLURGICA SINICA
(2022)
Article
Nanoscience & Nanotechnology
M. J. Szczerba
Summary: This study reports the first observations of giant magnetic-field-induced bending effect in Ni-Mn-Ga-Co-Cu alloys produced by the melt-spinning technique. The bending effect initiation was observed at a very low magnetic field, and the overall deformation was composed of plastic and elastic contributions, with the elastic contribution dominating in the later stages of the experiment.
SCRIPTA MATERIALIA
(2021)
Article
Materials Science, Multidisciplinary
Edelize Angelica Gomes, Eric Marchezini, Vanessa de Freitas Cunha Lins
Summary: The electrochemical properties of a Cu-Al-Ni-Mn shape memory alloy processed by spray-forming were evaluated using electrochemical impedance spectroscopy in a 3.5% w/v NaCl solution. The alloy was hot rolled and heat-treated at 250 degrees C and 550 degrees C. Heat treatment at 550 degrees C resulted in the formation of austenite. EDS analysis showed an enrichment of aluminum and manganese on the surface of the alloy after immersion in a saline solution. The impedance of the alloy, both untreated and heat-treated at 550 degrees C, increased significantly with increasing immersion time due to the formation of protective corrosion products. The SMA heat-treated at 250 degrees C exhibited the lowest corrosion resistance after 286 hours of immersion in a saline solution.
MATERIALS TODAY COMMUNICATIONS
(2023)
Article
Chemistry, Multidisciplinary
Peter D. B. Fischer, Stefan Martin, Alexander Walnsch, Martin Thuemmler, Mario J. Kriegel, Andreas Leineweber
Summary: Iron-based Fe-Mn-Al-Ni shape-memory alloys are cost-effective materials with remarkable pseudoelastic properties. The martensitic transformation of these alloys, studied through heat treatment and quenching, reveals a complex structure described by nanoscale twinned structure with tetragonal distortion. The lack of interstitial elements does not prevent the presence of these features.
JOURNAL OF APPLIED CRYSTALLOGRAPHY
(2021)
Article
Materials Science, Multidisciplinary
Shalini Singh, S. Karthick, I. A. Palani
Summary: This paper focuses on the development and performance testing of copper-based shape memory alloy coated optical fiber sensors. The study demonstrates performance differences of coated fibers at different rotational speeds, and analyzes the surface morphology, thickness, and thermal properties pre and post-coating. Static structural analysis in ANSYS Workbench reveals stress and strain in SMA coated fiber during bending.
Article
Chemistry, Multidisciplinary
Jose F. Gomez-Cortes, Maria L. No, Andrey Chuvilin, Isabel Ruiz-Larrea, Jose M. San Juan
Summary: Cu-Al-Ni is a high-temperature shape memory alloy (HTSMA) that exhibits exceptional thermomechanical properties and is suitable for high-temperature MEMS/NEMS technologies. Recent studies have shown that this alloy has robust superelastic behavior at the nanometer scale, making it a good choice for developing new generations of micro-/nano-electromechanical systems. The experimental results indicate that the Cu-Al-Ni thin films produced by solid-state diffusion have high thermal stability, which is suitable for the development of high-temperature MEMS/NEMS.
Article
Materials Science, Multidisciplinary
Y. J. Hu, X. Wang, J. Y. Wang, W. Zhai, B. Wei
Summary: The application of power ultrasound during the solidification of Cu-14wt pct Al-4.5 wt pct Ni alloy promoted the nucleation of primary austenite and influenced martensite transformation during subsequent quenching. The refinement of martensite phases and increase of beta 1' phase content due to ultrasound led to enhanced mechanical properties of the alloy, including increased yield strength, microhardness, and storage modulus.
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2021)
Article
Chemistry, Physical
Jiaojiao Yu, Jianjun Zhang, Qingzhou Wang, Hui Yu, Tianyuan Zheng, Fuxing Yin
Summary: By adding Al-La-B inoculant, the grains in a Cu-Al-Ni shape memory alloy (SMA) were successfully refined and further significantly refined after caliber rolling. However, alpha phase precipitation occurred. The tensile strength increased and elongation increased first and then decreased with the increase of rolling reduction, but increased monotonously after quenching treatment.
Article
Nanoscience & Nanotechnology
Mingzhu Dang, Honghao Xiang, Jikang Li, Chao Cai, Qingsong Wei
Summary: A copper-based shape memory alloy Cu-11.85Al-3.2Mn-0.1Ti with desirable superelasticity and shape memory effect was successfully printed by laser powder bed fusion (LPBF) technique. The printed alloy exhibited a microstructure composed of full beta(1)' martensite with a high density of stacking faults and twin crystals. Under temperature stimulation, the printed samples showed remarkable superelasticity and shape memory effect, demonstrating reliable shape recovery ability.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Thermodynamics
Witor Wolf, Eric M. Mazzer
Summary: The research found that the particle size and heat treatments of gas-atomized Cu-Al-Ni-Mn shape memory alloys have a significant impact on their thermodynamic properties, leading to changes in transformation energies. Particularly, there is a correlation between particle size and transformation temperatures, especially during the cooling process after solidification. After thermal cycling and annealing, the transformation temperatures increase, indicating the influence of atomic ordering in the austenitic phase.
THERMOCHIMICA ACTA
(2022)
Article
Materials Science, Multidisciplinary
Wenjia Wang, Yuanchao Ji, Minxia Fang, Dong Wang, Shuai Ren, Kazuhiro Otsuka, Yunzhi Wang, Xiaobing Ren
Summary: In this work, a systematic study of a reentrant strain glass transition in a Ti50Ni34Cu16 shape memory alloy is reported. The transition is characterized by temperature invariance, deviation in heat flow and resistivity curves, frequency-dependent behavior, and a peak in a zero-field cooling curve. In-situ microstructural observations reveal the unchanged B19 martensitic domain pattern and the emergence of nanodomains with local 4H symmetry. A new phase diagram is established based on experimental results, which helps understand the formation of the reentrant strain glass. The study predicts the presence of more unusual properties in reentrant strain glass materials.
Article
Materials Science, Multidisciplinary
Andrey Saren, Ville Laitinen, Mariia Vinogradova, Kari Ullakko
Summary: The additive manufacturing of magnetic shape memory (MSM) alloys is increasingly popular for manufacturing small devices with complex geometries and tailored properties. Laser powder bed fusion (L-PBF) has been shown to successfully manufacture magnetically actuated samples from Ni-Mn-Ga MSM alloys with a significant magnetic-field-induced strain. This research provides a detailed characterization of twin boundary (TB) mobility in L-PBF manufactured Ni-Mn-Ga alloys and identifies the influence of keyhole porosity defects on TB mobility and twinning stress. The results demonstrate the potential of L-PBF for manufacturing active parts from Ni-Mn-Ga but highlight the need for stable TB types and patterns for reliable and repeatable device operation.
Article
Materials Science, Multidisciplinary
Daniyal Abolhasani, Sang Wook Han, Chester J. VanTyne, Namhyun Kang, Young Hoon Moon
Summary: The study introduced a new method to enhance the shape memory effect and stability in Cu-Al-Ni shape memory alloys by partially reinforcing with alumina through selective laser melting. Partial reinforcement accumulates localized residual compressive stresses, increasing the shape memory effect, and a waistband effect is observed during cyclic compressive operation, facilitating higher strain recovery. These results confirm that partial reinforcement with alumina significantly enhances the shape memory effect of Cu-Al-Ni shape memory alloys.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Chemistry, Multidisciplinary
Vladimir Pushkarev, Hynek Nemec, Vaisakh C. Paingad, Jan Manak, Vlastimil Jurka, Vit Novak, Tomas Ostatnicky, Petr Kuzel
Summary: This study involves the preparation of high-quality single-crystalline GaAs nanobars arrays and the utilization of terahertz spectroscopy to investigate the electron motion inside the nanobars, revealing the surface effects on charge carrier dynamics.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Huseyin Sener Sen, Nabil Daghbouj, Mauro Callisti, Marek Vronka, Miroslav Karlik, Jan Duchon, Jaroslav Cech, Jan Lorincik, Vladimir Havranek, Petr Babor, Tomas Polcar
Summary: Nanolayered metallic alloys show different strain behavior under ion irradiation, depending on the thickness of the multilayer structure. The reasons behind this difference are revealed and validated by semianalytical modeling and local strain mapping. The study also uncovers the radiation-induced transition of the Zr/Nb interfaces from incoherent to partially coherent. Based on this work, a specific Zr/NbSS multilayer system with certain thickness is proposed for nuclear applications, which exhibits high radiation damage resistance and minimum swelling.
ACS APPLIED MATERIALS & INTERFACES
(2022)
Article
Materials Science, Multidisciplinary
N. Daghbouj, H. S. Sen, M. Callisti, M. Vronka, M. Karlik, J. Duchon, J. Cech, V Havranek, T. Polcar
Summary: Tailoring interfaces is an effective method for reducing radiation defect accumulation. Understanding the strain evolution caused by ion bombardment in nuclear materials is crucial for next-generation reactors. In this study, it was found that thin Zr/Nb-6 multilayers exhibit relatively high out-of-plane strain after Cu implantation, while thick Zr/Nb-96 shows minimal distortion. Local strain mapping and molecular dynamics simulations were used to identify the types of defects responsible for layer distortion and the differences between inner and interface-affected regions.
Article
Materials Science, Multidisciplinary
Y. Ge, M. Vronka, P. Vertat, M. Karlik, S. P. Hannula, O. Heczko
Summary: Three possible twinning modes and corresponding twin boundaries in 2H martensite of Cu 69.4 Ni 3.4 Al 27.2 single crystal were studied. The results show that these twin boundaries have differences and are closely related to twinning stress or twin-boundary mobility.
Article
Materials Science, Multidisciplinary
V. Mortet, A. Taylor, M. Davydova, M. Lamac, N. Lambert, I. Elantyev, J. Lorincik, D. Troadec, M. Vronka, S. Potocky
Summary: This study investigates the effect of pulsing methane during microwave plasma enhanced chemical vapor deposition on the growth of phosphorus-doped diamond, aiming to increase the doping efficiency and maximum concentration.
DIAMOND AND RELATED MATERIALS
(2022)
Article
Nanoscience & Nanotechnology
Ying Li, Jaromir Dlouhy, Jaroslav Vavrik, Jan Dzugan, Pavel Konopik, Tomas Krajnak, Jozef Vesely
Summary: The short-term creep performance of a coarse-grained Inconel 718 alloy fabricated using Directed energy deposition (DED) technique was investigated. The study found that superior creep strength and ductility can be achieved through specific heat treatment and sample orientation. The process-induced dislocation substructure and irregular columnar grains were found to contribute to the superior creep behavior.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Chemistry, Physical
Petr Cejpek, Petr Proschek, Ladislav Straka, Oleg Heczko
Summary: We investigated the dependence of martensite transformation temperature on magnetic field in Ni2MnGa and Ni2MnGa0.95In0.05 single crystals. The results showed that the martensite transformation temperature decreases in low magnetic fields and increases in high magnetic fields. The addition of 1.25 at% indium alloying not only reduces the transformation temperature, but also significantly decreases the latent heat of transformation.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
Article
Nanoscience & Nanotechnology
Lucia Bajtosova, Barbora Krivska, Rostislav Kralik, Jozef Vesely, Jan Hanus, Petr Harcuba, Jan Fikar, Ankit Yadav, Miroslav Cieslar
Summary: This study used molecular dynamics simulation method to investigate the mechanical properties of thin aluminum-based films, and compared the results with transmission electron microscope experiments. The simulation results matched well with the experimental results, revealing the importance of grain boundary processes in deformation.
SCRIPTA MATERIALIA
(2022)
Article
Materials Science, Multidisciplinary
Mayerling Martinez Celis, Jozef Vesely, Jirf Kozlik, Florent Picot, Petr Harcuba, Eric Hug
Summary: Microstructure changes were investigated in dissimilar friction stir welding of 316L and Al 5083 using electron microscopy techniques. The refinement of the structure in both base metals was observed, with the grain refinement of steel governed by continuous dynamic recrystallization. Different intermetallic compounds were identified in the welded region.
Article
Chemistry, Physical
Miroslav Karlik, Filip Prusa, Petr Kratochvil, Hana Thurlova, Angelina Strakosova, Jaroslav Cech, Jiri Capek, Marek Vronka, Marcello Cabibbo, Ondrej Ekrt
Summary: Three CoCrFeNiNbX alloys with 5 at.% SiC addition were prepared by mechanical alloying and spark plasma sintering. The alloys exhibited a combination of face-centered cubic solid solution, carbides, and Laves phase. Addition of Nb led to a decrease in the FCC solid solution fraction and an increase in NbC carbide and Laves phase content. Long-term annealing at 800 degrees C resulted in the disappearance of Cr7C3 carbide in the Nb5 alloy and formation of new oxides. The Nb5 alloy showed good strength and ductility, whereas Nb20 and Nb35 alloys became brittle. Nb35 alloy exhibited superior strength and comparable plasticity compared to Nb5 and Nb20 alloys at 800 degrees C.
Article
Materials Science, Multidisciplinary
M. Vinogradova, A. Sozinov, L. Straka, P. Vertat, O. Heczko, M. Zeleny, R. Chulist, E. Lahderanta, K. Ullakko
Summary: Martensites in Ni-Mn-Ga-based alloys have twin domains at micro-to-nanoscale, which affects the diffraction pattern and accuracy of crystal structure determination. This study proposes a method to obtain different martensitic phases in Ni-Mn-Ga-Fe alloy with simplified variant microstructures and domain sizes over 2 micrometers. The use of simplified variant microstructures allows circumvention of the influence of nanometer-scale domains on diffraction line position and enables comparison of lattice parameters of different martensitic phases in the same temperature range.
Article
Materials Science, Multidisciplinary
Petr Cejpek, Daria Drozdenko, Kristian Mathis, Ross H. Colman, Milan Dopita, Ladislav Straka, Oleg Heczko
Summary: A Ni50Mn28Ga22 single crystal with 10M martensitic structure was studied under uniaxial tensile stress using in situ X-ray diffraction. When the c axis was aligned with the applied stress, elongation primarily occurred through stress-induced reorientation. However, when the a or b axis was aligned with the stress, elongation was mainly due to changes in lattice parameters and a decrease in modulation amplitude of the 10M martensite. The initial tensile Young modulus was very low and gradually increased with increasing tensile stress, reaching a value of about 0.3 GPa at zero stress.
Article
Materials Science, Ceramics
R. Miksova, A. Jagerova, J. Cajzl, V. Holy, M. Vronka, A. Mackova
Summary: Gold nanoparticles (Au-NPs) were successfully created in crystalline yttria-stabilized zirconia (YSZ) and regulated through ion implantation and annealing. The disorder occurred in the region of Au-NPs, and the concentration of disorder increased with higher ion fluences. The formation and clustering of Au-NPs significantly affected the absorption properties of the material.
CERAMICS INTERNATIONAL
(2023)
Article
Materials Science, Ceramics
Miroslav Soroka, Josef Bursik, Radomir Kuzel, Lukas Horak, Jan Prokleska, Marek Vronka, Valentyn Laguta
Summary: This study reports the growth of epitaxial thin films of Sr2Co2Fe28O46 on a SrTiO3(111) substrate using a chemical solution deposition method. The orientation relationship between the film and substrate was determined to be (000l)X || (111)STO and [1120]X || [101]STO through X-ray diffraction analysis. The magnetization and magnetic domain structure were investigated using magnetic measurements and Lorentz transmission electron microscopy, revealing a spin reorientation transition and a change in magnetic anisotropy at different temperatures.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2023)
Article
Nuclear Science & Technology
A. Mackova, V. Havranek, R. Miksova, S. Fernandes, J. Matejicek, H. Hadraba, M. Vilemova, M. O. Liedke, J. Martan, M. Vronka, P. Hausild, M. Butterling, P. Honnerova, A. G. Attalah, A. Wagner, F. Lukac
Summary: The relationship between damage accumulation and lattice damage in high entropy alloys (HEAs) was studied through ion implantation experiments. By analyzing positron annihilation spectroscopy (PAS), thermal property analysis, and nanoindentation tests, it was found that HEA-Nb had less radiation hardening and radiation damage accumulation compared to other alloys.
NUCLEAR MATERIALS AND ENERGY
(2023)
