Article
Nanoscience & Nanotechnology
Zhirou Zhang, Qinghuan Huo, Lu Luo, Yuxiu Zhang, Zhenyu Xiao, Shiqi Li, Hiromi Nagaumi, Xuyue Yang
Summary: Age-hardening has been considered as an efficient way to enhance the creep resistance, but it unexpectedly deteriorated the creep resistance of a hot-rolled Mg-8wt%Gd alloy in this study. The precipitates formed during peak-aging treatment promoted the cracking of grain boundaries, resulting in the worsening of creep resistance. Meanwhile, the precipitation strengthening gradually reduced, leading to the acceleration of creep rate.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Nanoscience & Nanotechnology
Anastasia V. Mikhaylovskaya, Olga A. Yakovtseva, Natalia Yu. Tabachkova, Terence G. Langdon
Summary: During superplastic deformation of microduplex-structured brasses, strain primarily occurs in the beta-phase through grain boundary sliding and dislocation slip/creep mechanisms. Dynamic recrystallization and twinning transform the initial coarse beta-phase grains into ultrafine grains, and alloying with Al improves superplastic behavior and reduces residual cavitation.
SCRIPTA MATERIALIA
(2022)
Article
Nanoscience & Nanotechnology
Xiaoliang Ji, Lihua Wang, Yiping Xia, Fu Guo, Chunqing Wang
Summary: Previous research on high-symmetric metallic materials has shown that the introduction of twins can overcome the trade-off between strength and ductility. However, it was uncertain if this pathway would be valid for metals with a low-symmetry crystal structure. In this study, the low-symmetry body-centered tetragonal Sn achieved a simultaneous enhancement in tensile ductility and strength at 77 K through pre-twinning combined with room-temperature self-recrystallization. In-situ tensile experiments revealed that deformation twins, dynamic recrystallization, and multiple dislocation planar slip contributed to the improvement of cryogenic mechanical properties.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Yadong Ouyang, Longfei Huang, Haixia Liu, Guanglei Liu, Jie Chen, Hui Yu
Summary: This study investigated the effect of ultrasonic cavitation on CuZnAl alloy. Experimental work was conducted using an ultrasonic cavitation experimental rig. The microstructure and deformation of CuZnAl alloy were observed and analyzed at different exposure times. The results showed that ultrasonic cavitation treatment led to a refinement of the alloy's grain structure and a decrease in microhardness. Different deformation mechanisms were observed in the early and later stages of deformation induced by ultrasonic cavitation.
JOURNAL OF MATERIALS ENGINEERING AND PERFORMANCE
(2023)
Article
Nanoscience & Nanotechnology
Hidetoshi Somekawa, Jangho Yi, Hiromi Takahashi, Takanobu Hiroto, Koichi Tsuchiya
Summary: Experimental studies have revealed that many cavities are formed at grain boundaries and grain boundary triple junctions of fine-grained magnesium specimens during plastic deformation at room temperature, and the size and density of these cavities increase with the progression of deformation. The majority of cavities are controlled by plasticity, and their growth rate is similar to those observed in superplastic magnesium alloys tested at elevated temperatures.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Nanoscience & Nanotechnology
Qizhen Li
Summary: The study investigated the effect of testing temperature on mechanical properties and deformation mechanisms of fine-grained magnesium samples through tensile testing. The results show that both mechanical properties and deformation mechanisms were significantly affected by the variation of testing temperature, with strength increasing linearly and ductility decreasing linearly with decreasing temperature. The dominating deformation mechanism shifted from tensile twinning at room temperature to negligible twinning and primary dislocation operation at subfreezing temperatures.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Nanoscience & Nanotechnology
Chunyu Wang, Yuxiu Zhang, Qinghuan Huo, Zhirou Zhang, Jiao Tang, Aki Hashimoto, Xuyue Yang
Summary: This study investigated the effects of twinning time node on the creep resistance of an extruded Mg-2wt%Y sheet. Pre-compression with a low strain before creep resulted in a large amount of {10 (1) over bar2} twins, impacting the creep resistance of the samples. The dominant creep mechanisms differed between samples with and without pre-compression, with the presence of twins affecting the creep rate.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2021)
Article
Materials Science, Multidisciplinary
Rui Guo, Qiang Wang, Yingze Meng, Wenlong Xu, Guojun Li, Zhimin Zhang, Huisheng Yu, Jianmin Yu
Summary: Currently, alloys undergo deformation under various stress states, and the influence of these stresses on material deformation is not well understood. This study investigates the internal deformation mechanism of the Mg-13Gd-4Y-2Zn-0.5Zr alloy under two stress states through compression and torsion experiments. The results reveal that the deformation behavior of the alloy differs under shear stress and compressive stress, and factors such as dislocation slip and twinning play crucial roles.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2022)
Article
Engineering, Mechanical
Xiaolei Xing, Qiang Wang, Shuo Meng, Qingxiang Yang, Yefei Zhou
Summary: The fatigue behavior of a new bearing steel with carbide-free bainite was investigated. The rolling contact fatigue life of the bainitic layer was significantly higher than that of the commercial GCr15 steel sample. The improved toughness of the bainitic layer was attributed to the presence of bainitic ferrite and retained austenite.
Article
Chemistry, Physical
Elango Chandiran, Yukiko Ogawa, Rintaro Ueji, Hidetoshi Somekawa
Summary: The effect of grain size and strain rate on the room-temperature compression of pure magnesium was studied. It was found that the deformation mechanisms and grain-boundary sliding were significantly influenced by grain size and strain rate, and the Hall-Petch relationship broke down under certain conditions. Additionally, the deformation mode had a negligible impact on the dominant deformation mechanisms and the Hall-Petch breakdown.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Chemistry, Physical
Jiao Tang, Qinghuan Huo, Zhirou Zhang, Yuxiu Zhang, Shilin Zhao, Aki Hashimoto, Xuyue Yang
Summary: This study investigated how to enhance the creep resistance of dilute Mg-Nd alloys through pre-compression and subsequent peak-aging. By studying samples with different treatments, it was found that the PC-AA sample exhibited the best creep resistance, followed by the NPC sample, and the PC sample showed the poorest performance.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Chemistry, Physical
Yuxiu Zhang, Yibing Li, Qinghuan Huo
Summary: This study investigated the effects of grain size on the compressive creep behavior of a Mg-10.5 wt%Y alloy. It was found that the decrease in grain size led to a deterioration in creep resistance. Different creep mechanisms were observed in samples with different grain sizes, and precipitate-free zones were observed on grain boundaries. The fine-grained samples exhibited poor creep resistance, even without grain boundary sliding.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Nanoscience & Nanotechnology
Jiaxiang Li, Qinghuan Huo, Chunyu Wang, Yuxiu Zhang, Zhirou Zhang, Gang Feng, Xuyue Yang
Summary: The results of the study demonstrated a clear tension-compression asymmetry in the creep behavior of the alloy under tensile and compressive creep loading along the rolling direction and the normal direction. Twinning played a role in deteriorating the creep resistance of certain samples and causing asymmetrical behavior in the results. The T-RD sample showed the best creep resistance, while the C-ND sample followed, with the C-RD and T-ND samples showing similarly poor creep resistance.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2022)
Article
Materials Science, Multidisciplinary
Yu-qin Zhang, Wei-li Cheng, Hui Yu, Hong-xia Wang, Xiao-feng Niu, Li-fei Wang, Hang Li
Summary: This study systematically investigated the twinning behavior, dynamic recrystallization (DRX) mechanism, and texture evolution of extruded Mg-xBi (x=0.5 wt.%, 2.0 wt.%) alloys during hot compression. The results show that the texture types and intensities are closely related to twinning behavior and DRX mechanism. The formation and variation of {10 (1) over bar2} extension twins dominate the early evolution of texture, while the DRX mechanism plays a greater role as the strain increases.
JOURNAL OF MATERIALS SCIENCE & TECHNOLOGY
(2022)
Article
Metallurgy & Metallurgical Engineering
Chong Yang, Guoguo Zhu, Hui Zhao, Yan Peng, Baodong Shi
Summary: The Swift effect of Mg alloy is influenced by initial texture, and dislocation slip is the main deformation mechanism during torsion. The relationship between Swift effect and dislocation slip is still unclear. Experimental study on the effect of stress state and pre-straining during free-end torsion was conducted on an AZ31 alloy. It was found that the axial deformation changes from contraction to elongation when the axial stress changes from negative to positive. Pre-dislocations from pre-tension promote axial shortening, while pre-twins from pre-compression inhibit axial shortening. The change in axial deformation is attributed to the competition between twinning and prismatic slip.
JOURNAL OF MAGNESIUM AND ALLOYS
(2023)
Article
Chemistry, Physical
Zuzanka Trojanova, Zdenek Drozd, Kristyna Halmesova, Jan Dzugan, Tomas Skraban, Peter Minarik, Gergely Nemeth, Pavel Lukac
Summary: An extruded magnesium AZ31 alloy was processed by rotary swaging and then deformed by tension and compression at room temperature. The work-hardening behavior was analyzed, indicating that dislocation accumulation on obstacles and twin boundaries plays a decisive role in strain hardening. Profuse twinning in compression leads to higher hardening, while the main softening mechanism is attributed to cross-slip between pyramidal planes of different orders.
Article
Chemistry, Physical
Lenka Kucharikova, Denisa Medvecka, Eva Tillova, Juraj Belan, Michaela Kritikos, Maria Chalupova, Milan Uhricik
Summary: This study investigated the impact of higher Fe content on the microstructure and properties of A356.0 alloy, showing that Fe-rich plate-like phases can limit pore growth but lead to increased porosity formation with higher thickness. Mechanical and fatigue properties were found to correlate with Fe-crit level, with the best performance seen in the experimental alloy with 0.454 wt.% Fe content.
Article
Materials Science, Multidisciplinary
Zuzanka Trojanova, Zdenek Drozd, Pavel Lukac, Jan Dzugan
Summary: This study conducted stress-relaxation tests on magnesium Mg-Li alloys and their composite materials, analyzing the thermally activated processes in different structures, and found that dislocation motion and recovery processes vary in different structures.
Article
Energy & Fuels
Stefan Kocan, Pavol Rafajdus, Ronald Bastovansky, Richard Lenhard, Michal Stano
Summary: This paper discusses the design and optimization process of a switched reluctance motor as an alternative to high-speed permanent-magnet synchronous motors. Analytical and finite element methods were used for analysis, leading to a design that met all requirements and limits.
Article
Chemistry, Physical
Zuzanka Trojanova, Zdenek Drozd, Kristyna Halmesova, Jan Dzugan, Tereza Hofrichterova, Peter Palcek, Peter Minarik, Tomas Skraban, Frantisek Novy
Summary: The magnesium AZ31 alloy was improved in mechanical and fatigue properties through rotary swaging. The swaged samples showed significantly enhanced fatigue performance with a substantial increase in endurance limit.
Article
Engineering, Manufacturing
Martin Mikolajcik, Eva Tillova, Lenka Kucharikova, Lucia Pastierovicova, Maria Chalupova, Milan Uhricik, Zuzana Surdova
Summary: The use of secondary aluminium alloys allows manufacturers to produce products more economically and environmentally friendly. However, recycled aluminium alloys have a higher content of impurities due to insufficient sorting. Iron is the most common undesirable element in Al-Si-Mg cast alloys, affecting mechanical properties negatively. The addition of manganese can reduce the influence of iron.
MANUFACTURING TECHNOLOGY
(2022)
Article
Engineering, Manufacturing
Zuzana Surdova, Lenka Kucharikova, Eva Tillova, Lucia Pastierovicova, Maria Chalupova, Milan Uhricik, Martin Mikolajcik
Summary: The use of secondary aluminium alloys has the potential to save energy and money while reducing the negative environmental impact of aluminium production. However, increased iron content can decrease the corrosion resistance of these alloys.
MANUFACTURING TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Lenka Kucharikova, Lucia Pastierovicova, Eva Tillova, Milan Uhricik, Viera Zatkalikova, Michal Sajgalik
Summary: This study focuses on the research of secondary AlSi7Mg0.3 cast alloys containing more Fe and affected by a chloride corrosive environment. The results show that a higher Fe content does not significantly reduce the properties of the casting, and the chloride environment is not so harmful. Therefore, it can be concluded that the investigated secondary sand-cast experimental materials can replace primary alloys without losing the required corrosion and mechanical properties.
Article
Engineering, Industrial
Juraj Belan, Eva Tillova, Milan Uhricik, Lucia Pastierovicova
Summary: Despite the trend in the automotive industry towards using modern materials based on Al or HSLA steels, cast iron still holds value due to its price and excellent castability. This article explores the use of ultrasonic non-destructive testing to simplify the identification of cast iron types based on ultrasound propagation parameters. The main criteria for assessing quality and determining the type of graphite cast iron are the rate of ultrasound propagation (c(L)) and the attenuation value (alpha), which vary based on the graphite and matrix shape. The study involved different graphite shapes and matrix ratios, and metallographic analysis was also performed.
PRODUCTION ENGINEERING ARCHIVES
(2023)
Article
Engineering, Industrial
Lucia Pastierovicova, Lenka Kucharikova, Eva Tillova, Maria Chalupova, Richard Pastircak
Summary: This paper focuses on the quality and mechanical properties of AlSi6Cu4 castings with different wall thicknesses in metal molds. It is found that the castings with smaller wall thicknesses have finer structural components and better mechanical properties, making them suitable for the automotive industry.
PRODUCTION ENGINEERING ARCHIVES
(2022)
Proceedings Paper
Optics
Norbert Tarjanyi, Daniel Kacik, Milan Uhricik, Peter Palcek
Summary: The paper presents an investigation of polymethylmetacrylate deformation due to applied high-load utilizing its birefringence. The measured data showed a good match with calculated models, indicating the potential use of the models for calibrating PMMA-based sensors for load and deformation.
OPTICAL SENSING AND DETECTION VI
(2021)
Article
Metallurgy & Metallurgical Engineering
M. Matejka, D. Bolibruchova, M. Chalupova
Summary: Recycling of aluminium returnable material through its reuse is now an essential component of the production of aluminium alloy castings. The goal is to find the right balance between the primary alloy and returnable material in order to maintain the quality of the casting. Experimental evaluation of alloys showed that changes in properties occurred with an increase in returnable material, with degradation observed beyond a certain ratio.
ARCHIVES OF METALLURGY AND MATERIALS
(2021)
