Article
Materials Science, Multidisciplinary
Sean Peters, Aurik Andreu, Marcos Perez, Paul Blackwell
Summary: The objective of this study was to improve the forging outcome of peritectic solidifying cast TiAl 4822 alloy in HH condition using CHT. The results show that CHT improved the forging outcomes for both compression stages investigated, resulting in uniform compression samples with higher volumes of dynamic recrystallised material compared with HH material.
Article
Nanoscience & Nanotechnology
Zhenquan Liang, Shulong Xiao, Qingchao Li, Hongbao Yu, Yunfei Zheng, Lijuan Xu, Xiang Xue, Jing Tian, Yuyong Chen
Summary: The tensile creep behavior of a heat treated beta-solidified gamma-TiAl alloy was investigated at 800 degrees C and 250-300 MPa. The heat treatment improved the creep resistance of the alloy. Creep deformation is dominated by viscous dislocation glide and assisted by mechanical twinning. Twin boundary and TiB hinder dislocation movement and strengthen creep resistance. Dynamic recrystallization and B2 phase precipitation occur during creep. Creep voids prefer to nucleate at the gamma-B2 and B2-colony interfaces, leading to brittle-ductile mixed fracture.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
Jieren Yang, Zitong Gao, Yongfeng Liang, Yulun Wu, Jinguang Li, Rui Hu
Summary: Fine-grained nearly-lamellar (FGNL) microstructures and ultrafine alpha(2)/gamma lamellar microstructures were successfully obtained by means of alpha-recrystallization in a Tie48Ale2Nb e2Cr alloy. The microstructure refinement is governed by small-strain alpha-deformation, with dominating continuous dynamic recrystallization (CDRX) responsible for lamellar grain refinement.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Nanoscience & Nanotechnology
Guoming Zheng, Bin Tang, Songkuan Zhao, Yizhen Xie, William Yi Wang, Jinshan Li, Lei Zhu
Summary: Dislocation slipping and mechanical twinning control the plastic deformation of lamellar micro-structure (LM) in TiAl intermetallics. However, when the interlamellar spacing is reduced to the nanometer scale, the deformation mechanism switches to the development of long-period stacking-ordered (LPSO) structures. The formation of LPSO structures during deformation can result in greater high-temperature yield strength compared to LMs deformed via dislocation gliding or mechanical twinning.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Materials Science, Multidisciplinary
David Wimler, Katharina Kaesznar, Michael Musi, Christoph Breuning, Matthias Markl, Jozef Keckes, Helmut Clemens, Carolin Koerner, Svea Mayer
Summary: This study investigates the impact of different process parameters on the aluminum content and microstructure of an alloy based on γ-TiAl during additive manufacturing, with examinations using electron microscopy, X-ray spectroscopy, and diffraction experiments. The results demonstrate a decrease in the gamma-TiAl phase content with increasing energy input, affecting the mechanical properties after heat treatment. The preferred orientation of the gamma phase at high energy inputs is attributed to the directional solidification of the beta phase.
MATERIALS & DESIGN
(2021)
Article
Chemistry, Physical
Dmitrii Panov, Stanislav Naumov, Nikita Stepanov, Vitaliy Sokolovsky, Elena Volokitina, Nikolai Kashaev, Volker Ventzke, Rene Dinse, Stefan Riekehr, Elizaveta Povolyaeva, Nadezda Nochovnaya, Evgeniy Alekseev, Sergey Zherebtsov, Gennady Salishchev
Summary: The effect of pre-heating and post-weld heat treatment on microstructure and mechanical properties of laser-welded joints in a Ti-23Al-23Nb-1.4V-0.8Zr-0.4Mo-0.4Si (at.%) alloy was investigated. The results showed that an increase in pre-heating temperature led to the growth of columnar beta crystals and widening of the fusion zone and heat-affected zone. The decrease in Al and Ti content, as well as the increase in porosity and gaseous elements content, were observed after welding at higher temperatures. The joints exhibited lower microhardness than the base material, but their yield strength and ultimate tensile strength levels were relatively high. Reasonable total elongation could be achieved under certain conditions.
Article
Chemistry, Physical
J. Ibanez-Perez, M. L. No, M. Oehring, H. Clemens, J. M. San Juan
Summary: This study demonstrates the hindering effect of Nb on the diffusion of Ti atoms in the α(2)-Ti3Al phase through mechanical spectroscopy measurements, with the activation energy increasing with Nb content. The mechanism of next-neighbor interaction of Nb atoms with the local configuration of Ti-V-Ti is proposed to explain the observed experimental behavior, leading to a further broadening of the relaxation peak.
JOURNAL OF ALLOYS AND COMPOUNDS
(2021)
Article
Materials Science, Multidisciplinary
Maria L. No, Thomas Klein, Helmut Clemens, Jose M. San Juan
Summary: This study provides a comprehensive investigation on the microstructure evolution of Nano-lamellar advanced gamma-TiAl based alloys using electron microscopy techniques. The results show that the precipitation of beta o and zeta phases delays the coarsening of the gamma lamellae, contributing to the enhanced creep resistance of the alloy.
Review
Materials Science, Multidisciplinary
Yu-ting Wu, Chong Li, Ye-fan Li, Jing Wu, Xing-chuan Xia, Yong-chang Liu
Summary: The heat treatment of Ni3Al-based alloys significantly influences the microstructure of the alloys and desirable mechanical properties can be achieved through heat treatment. Additionally, the evolution of secondary phases during heat treatment, including the kinetics of precipitate growth, and the effects of heat treatment on the mechanical properties of the alloys are discussed.
INTERNATIONAL JOURNAL OF MINERALS METALLURGY AND MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Zhenquan Liang, Shulong Xiao, Hangyu Yue, Xinyi Li, Qingchao Li, Yunfei Zheng, Lijuan Xu, Xiang Xue, Jing Tian, Yuyong Chen
Summary: This study investigates the effects of heat treatment on the microstructure and oxidation behavior of Ti-45Al-8Nb alloy prepared by selective electron beam melting. The results indicate that the microstructure of the alloy changes from near-gamma structure to duplex structure after heat treatment, but both exhibit heterostructure characteristics. Oxidation tests demonstrate that heat treatment can effectively enhance the oxidation resistance of the alloy, mainly due to the optimization of phase constitution, the introduction of more twin boundaries, and the formation of a continuous AlNb2 barrier layer, which inhibit the inward diffusion of oxygen ions into the substrate.
Article
Chemistry, Physical
David Wimler, Janny Lindemann, Thomas Kremmer, Helmut Clemens, Svea Mayer
Summary: Alloy development based on the intermetallic gamma-TiAl phase has gained renewed interest, with powder metallurgical approaches providing new processing options. Manufacturing via spark plasma sintering allowed for the production of two alloys with specific microstructures, exhibiting high creep strength and resistance. The formation and growth kinetics of carbides are closely linked to the mechanical response of the microstructure, with heat treatment at 800 degrees C leading to the formation of fine carbides and increased strength. The investigated alloys demonstrate ductile behavior at temperatures up to 750 degrees C (BMBF3), while the BMBF2 alloy is considered usable up to 850 degrees C.
Article
Chemistry, Physical
Hui Xue, Xinhuan Tong, Yi Song, Feng Wang, Yongfeng Liang, Hui Peng, Yanli Wang, Junpin Lin
Summary: Developing a new ordered single-phase TiAl alloy without solid-state transformation at high temperature is crucial in the aerospace industry. This study proposes and investigates the preparation of Ti-55Al-7.5Nb alloy through direct laser deposition (DLD). By utilizing laser additive manufacturing (AM), oriented grain growth in Ti-55Al-7.5Nb alloy is achieved without interruption during the laser scanning. The Ti-55Al-7.5Nb alloy undergoes a direct transformation into a γ single-phase, confirmed through experiments and thermodynamic calculations, due to the rapid cooling rate of AM and the narrow phase transformation temperature window of the alloy.
Article
Materials Science, Multidisciplinary
Zhenquan Liang, Shulong Xiao, Yi Shao, Dazhao Chi, Xinyi Li, Yunfei Zheng, Lijuan Xu, Xiang Xue, Jing Tian, Yuyong Chen
Summary: In this study, the short-term creep behaviors of high Nb containing TiAl alloys with different microstructure characteristics at 800°C under a wide range of stresses were investigated. It was found that increasing Al content and introducing C and Y2O3 can effectively reduce the steady-state creep rate and enhance the creep resistance, with the latter having a more significant effect. The creep behavior of high Nb containing TiAl alloys strongly depends on the stress level and the corresponding creep deformation mechanism changes accordingly.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Physics, Applied
M. Kratzer, M. Huszar, L. Tengg, T. Billovits, B. Kaufmann, P. Supancic, H. Clemens, S. Mayer, C. Teichert
Summary: The study reveals that different phases of γ-TiAl-based alloys exhibit significantly different resistivity values. Results from CAFM and μ4PP measurements show good agreement for the α(2) and γ phases, while measurements of the β(o) phase using μ4PP are unreliable due to the formation of a contact barrier.
JOURNAL OF APPLIED PHYSICS
(2021)
Article
Materials Science, Multidisciplinary
Michael Musi, Christophe Deshayes, Guy Molenat, Louise Toualbi, Benjamin Galy, Petra Spoerk-Erdely, Muriel Hantcherli, Jean-Philippe Monchoux, Marc Thomas, Helmut Clemens, Alain Couret
Summary: This study presents the microstructure and mechanical properties of a TNM+ alloy densified by Spark Plasma Sintering (SPS), in comparison to the as-SPSed TNM alloy. The incorporation of carbon and silicon leads to an increase in creep resistance at 800 degrees C but poor ductility at room temperature.
Article
Chemistry, Physical
T. Shanmugasundaram, J. Guyon, J. P. Monchoux, A. Hazotte, E. Bouzy
Article
Microscopy
J. Guyon, H. Mansour, N. Gey, M. A. Crimp, S. Chalal, N. Maloufi
Article
Materials Science, Multidisciplinary
J. Guyon, A. Hazotte, F. Wagner, E. Bouzy
Article
Materials Science, Multidisciplinary
M. Mondet, E. Barraud, S. Lemonnier, J. Guyon, N. Allain, T. Grosdidier
Article
Microscopy
Julien Guyon, Nathalie Gey, Daniel Goran, Smail Chalal, Fabian Perez-Willard
Article
Microscopy
J. J. Fundenberger, E. Bouzy, D. Goran, J. Guyon, H. Yuan, A. Morawiec
Article
Materials Science, Multidisciplinary
Subrata Panda, Laszlo S. Toth, Jean-Jacques Fundenberger, Olivier Perroud, Julien Guyon, Jianxin Zou, Thierry Grosdidier
MATERIALS CHARACTERIZATION
(2017)
Article
Materials Science, Multidisciplinary
Etienne Brodu, Emmanuel Bouzy, Jean-Jacques Fundenberger, Julien Guyon, Antoine Guitton, Yudong Zhang
MATERIALS CHARACTERIZATION
(2017)
Article
Nanoscience & Nanotechnology
H. Queudet, S. Lemonnier, E. Barraud, J. Guyon, J. Ghanbaja, N. Allain, E. Gaffet
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2017)
Article
Chemistry, Physical
Antoine Guitton, Hana Kriaa, Emmanuel Bouzy, Julien Guyon, Nabila Maloufi
Article
Nanoscience & Nanotechnology
H. Mansour, J. Guyon, M. A. Crimp, N. Gey, B. Beausir, N. Maloufi
SCRIPTA MATERIALIA
(2014)
Article
Materials Science, Multidisciplinary
J. Zollinger, B. Rouat, J. Guyon, S. K. Pillai, M. Rappaz
METALLURGICAL AND MATERIALS TRANSACTIONS A-PHYSICAL METALLURGY AND MATERIALS SCIENCE
(2019)
Article
Chemistry, Physical
Meriem Ben Haj Slama, Nabila Maloufi, Julien Guyon, Slim Bahi, Laurent Weiss, Antoine Guitton
Article
Materials Science, Multidisciplinary
C. Ernould, V. Taupin, B. Beausir, J. J. Fundenberger, N. Maloufi, J. Guyon, E. Bouzy
Summary: In this study, a high-angular resolution electron backscatter diffraction technique based on global image registration of Kikuchi patterns is used to investigate a nanopipe threading screw dislocation in a GaN layer. The experimental and simulated results qualitatively agree, indicating the presence of a screw dislocation with a Burgers vector magnitude of 3c = 1.56 nm.
MATERIALS CHARACTERIZATION
(2022)
Article
Chemistry, Physical
J. Zamora, T. Bautista, N. S. Portillo-Velez, A. Reyes-Montero, H. Pfeiffer, F. Sanchez-Ochoa, H. A. Lara-Garcia
Summary: Experimental and DFT studies were conducted on the structural, magnetic, and optical properties of RFeO3 perovskites. The perovskites exhibited an orthorhombic crystal structure and weak ferromagnetic behavior. They were confirmed to be semiconductors with a bandgap of approximately 2.1 eV.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Xianxiang Lv, Jing Jin, Weiguang Yang
Summary: By depositing TiN and TiO2 surface layers on AlSi films, the electrochemical performance of silicon-based anodes can be significantly improved, suppressing volume expansion and promoting the formation of a stable SEI layer.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Sharafat Ali, Haider Ali, Syedul Hasnain Bakhtiar, Sajjad Ali, Muhammad Zahid, Ahmed Ismail, Pir Muhammad Ismail, Amir Zada, Imran Khan, Huahai Shen, Rizwan Ullah, Habib Khan, Mohamed Bououdina, Xiaoqiang Wu, Fazal Raziq, Liang Qiao
Summary: The construction and optimization of redox-heterojunctions using a bifunctional phosphate as an electron-bridge demonstrated significant improvements in photo catalytic activity, including enhanced dispersion, reduced interfacial migration resistance, and increased abundance of active-sites.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Ren-Ni Luan, Na Xu, Chao-Ran Li, Zhi-Jie Zhang, Yu-Sheng Zhang, Jun Nan, Shu-Tao Wang, Yong-Ming Chai, Bin Dong
Summary: Extensive research has revealed that oxygen evolution reaction (OER) in alkaline conditions involves dynamic surface restructuring. The development and design of sulfide/oxide pre-catalysts can reasonably adjust the composition and structure after surface reconstruction, which is crucial for OER. This study utilized a simple two-step hydrothermal method to achieve in situ S leaching and doping, inducing the composition change and structure reconstruction of CoFe oxides. The transformed FeOOH and CoOOH exhibited excellent OER activity and could be easily mass-produced using low-cost iron based materials and simple methods.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Jun'an Lai, Daofu Wu, Peng He, Kang An, Yijia Wang, Peng Feng, WeiWei Chen, Zixian Wang, Linfeng Guo, Xiaosheng Tang
Summary: Zero-dimensional organic-inorganic metal halides (OMHs) are gaining attention in the fabrication of light-emitting diodes due to their broad emission band and high photoluminescence quantum yield. This work synthesized a zero-dimensional organic tetraphenylphosphonium bismuth chloride (TBC) that showed efficient blue light emission, with the emission mechanism attributed to the transition of Bi3+ ions. White light-emitting diodes (WLEDs) were fabricated using TBC, along with green-emitting and red-emitting single crystals, achieving single-component white emissions. These findings demonstrate the different emission mechanism of ns2 ions-based OMHs and highlight the potential of bismuth-based OMHs in WLEDs applications.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Xuewei Liang, Yunhai Su, Taisen Yang, Zhiyong Dai, Yingdi Wang, Xingping Yong
Summary: The revolutionary design concept of high-entropy alloys has brought new opportunities and challenges to the development of advanced metal materials. In this work, AlCrCuFe2NiTix high-entropy flux cored wires were prepared by combining the design idea of a high-entropy alloy with the characteristics of flux cored wire. AlCr-CuFe2NiTix high-entropy surfacing alloys were prepared using gas metal arc welding technology. The wear properties of the alloys were analyzed, and the phase composition, microstructure, strengthening mechanism, and wear mechanism were discussed. The results show that the alloys exhibit a dendritic microstructure with BCC/B2 + FCC phases. Increasing Ti content leads to the precipitation of Laves phase. The alloys show improved microhardness and wear resistance due to the precipitation of coherent B2 and Laves phases. However, excessive Ti addition results in the increase of Laves phase and reduced wear resistance of the alloys.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
M. Vadivel, M. Senthil Pandian, P. Ramasamy, Qiang Jing, Bo Liu
Summary: This work presents the enhanced photocatalytic and electrochemical performance of g-C3N4 assisted PAA on CoFe2O4 ternary nanocomposites. The incorporation of PAA and g-C3N4 improves the separation efficiency of photogenerated charge carriers, resulting in superior photocatalytic degradation and high specific capacitance values.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Vibhu T. Sivanandan, Ramany Revathy, Arun S. Prasad
Summary: In this study, pure and doped cobalt ferrite nanoparticles were prepared using the sol-gel auto-combustion method with the aid of lemon juice as eco-fuel. The crystal structure, lattice parameter, crystallite size, microstrain, optical parameters, and room temperature magnetic properties of the samples were analyzed. The effect of doping on the magnetic properties was also investigated.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Qing Guo, Bowen Zhang, Benzhe Sun, Yang Qi
Summary: This study prepared ZnO films with various nonpolar preferred orientations using conventional chemical bath deposition method and characterized their growth process and mechanism. It was found that the type and concentration of nitrate could control the preferred orientation and surface roughness of ZnO films. Additionally, ZnO films with different preferred orientations exhibited different optical properties.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Chong Zhang, Yan Liu, Zhaoyan Wang, Hang Yang
Summary: In this study, six bimetallic FeCo particles were synthesized via the hydrothermal method at different Fe:Co ratios. The Fe:Co ratio not only modulates the composition of the particles but also influences their structure and magnetic properties. The FeCo alloys showed a transformation from an Fe-based structure to a Co-based structure with increasing Co content. The Fe:Co ratio of 1:1 and 3:1 resulted in particles with the highest and lowest saturation magnetization, respectively.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Jianning Zhang, Jing Li, Yiren Wang, Xiaodong Mao, Yong Jiang
Summary: We conducted a study on the formation of ultra-fine Y-Ti-Ta-O nano-oxides in Ta+B micro-alloyed 13CrWTi-ODS alloys using electron microscopy and first-principles calculations. The Y-Ti-Ta-O nano-oxides were found to be mainly Y2(Ti,Ta)2O7, with an average size of 7 nm and a number density of 6.8 x 1023 m-3. Excess boron was found to enhance the adhesion of some low-sigma grain boundaries but weaken the Fe/Y2Ti2O7 interface, while excess tantalum enhanced the Fe/Y2Ti2O7 interface but caused serious degradation of grain boundaries.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Yirong Fang, Pei Cheng, Hang Yuan, Hao Zhao, Lishu Zhang
Summary: A new composite system of nitrogen-doped reduced graphene oxide and black phosphorus quantum dots has been developed for tumor therapy, showing improved electrochemical properties and stability. The system generates hydrogen peroxide and hydroxyl radical to effectively kill tumor cells.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Xiufang Qin, Yuanli Ma, Hui Zhang, Ting Zhang, Fang Wang, Xiaohong Xu
Summary: The structure and magnetism of cobalt ferrites after Mn2+-Tb3+ co-doping were studied. Co-doped samples exhibited cubic spinel structure and spherical shape of ferrite nanoparticles. The redistribution of Co2+ and Fe3+ ions between octahedral and tetrahedral sites was observed due to Mn2+-Tb3+ co-doping. The coercivity and magnetization saturation of co-doped samples were significantly improved, leading to a maximum energy product that is 190% higher than that of the un-doped sample.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Ho Yeon Lee, Wonjong Yu, Yoon Ho Lee
Summary: Recently, there has been an increasing interest in developing ultra-fine nanostructured electrodes with extensive reaction areas to enhance the performance and low-temperature operation of solid oxide fuel cells. The use of a refined approach involving co-sputtering metal alloys and oxide targets has demonstrated the feasibility of nano-columnar structures in perovskite-based electrodes, expanding the temperature range of thin film electrodes. This study systematically examines the effects of chamber pressure control in the co-sputtering process and identifies the intricate relationship between sputtering pressure and film structure. By fine-tuning the columnar growth in the electrode, significant improvements in performance and thermo-mechanical properties were achieved, resulting in high-performance all-sputtered solid oxide fuel cells.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)
Article
Chemistry, Physical
Qianyun Bai, Xiaoxiao Yan, Da Liu, Kang Xiang, Xin Tu, Yanhui Guo, Renbing Wu
Summary: This study proposes a simple method to develop a non-precious transition metal-based electrocatalyst with high catalytic activity and robustness for the hydrogen evolution reaction. The as-synthesized electrode exhibits a low overpotential and high current density, indicating its potential in energy conversion.
JOURNAL OF ALLOYS AND COMPOUNDS
(2024)