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
Chemistry, Physical
Ali Shaaban, Hirotoyo Nakashima, Mitsutoshi Ueda, Masao Takeyama
Summary: This study investigated the effects of oxygen addition on TiAl alloys at 1023 K, finding that it stabilized the alpha phase, reduced oxidation mass gains, and altered microstructure and phase transformations without significantly affecting oxidation resistance.
JOURNAL OF ALLOYS AND COMPOUNDS
(2022)
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)
Review
Materials Science, Multidisciplinary
Michael Musi, Gloria Graf, Helmut Clemens, Petra Spoerk-Erdely
Summary: This review provides a detailed survey of the research work on the influence of technically important alloying elements on the Ti-Al phase diagram in γ-TiAl based alloys. After introducing the fundamentals of phase transformations, the alloying elements are discussed and their particularities are highlighted.
ADVANCED ENGINEERING MATERIALS
(2023)
Article
Chemistry, Physical
Zhengkun Cai, Qianqian Guo, Minjin Jiang, Xiaosong Jiang, Song Chen, Hongliang Sun
Summary: The presence of water vapor significantly increased the oxidation kinetics of TiAl-based alloys and changed the morphology of the oxide scales; Air-water vapor environment enhanced the directional growth of TiO2; The different added elements led to different oxidation behaviors of TiAl-based alloys in this environment.
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
Nanoscience & Nanotechnology
Jun Cao, Tielong Sun, Zhichao Guo, Gang Yang, Yongfeng Liang, Junpin Lin
Summary: This study demonstrates that trace carbon alloying can significantly improve the room-temperature mechanical properties of a cast Ti-46Al-6Nb alloy. By improving multiple factors simultaneously, this research offers an accurate and feasible strategy for utilizing interstitial carbon to solid-solution strengthen TiAl alloys.
MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
(2023)
Article
Metallurgy & Metallurgical Engineering
Yi Jia, Zhi-dong Liu, Sha Li, Hao-ming Yao, Zhong-kai Ren, Tao Wang, Jian-chao Han, Shu-long Xiao, Yu-yong Chen
Summary: The study investigated the effects of different cooling rates and 0.25 at.% TiB2 addition on the solidification microstructure and mechanical properties of Ti-48Al-2Cr-2Nb alloys. Results showed that changing the cooling rate and adding TiB2 could refine the grain size and improve the mechanical properties of the alloy.
TRANSACTIONS OF NONFERROUS METALS SOCIETY OF CHINA
(2021)
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
Materials Science, Multidisciplinary
Xuesong Yang, Xuewen Li, Tongtong Zhang, Chao Xu, Guohua Fan, Jie Zhang
Summary: A novel laminated TiAl matrix composite with alternating equiaxed grain layers and fully lamellar grain layers was successfully fabricated using hot pressing and multi-step reaction annealing. The oxidation behavior of the composite at 800 degrees C was studied, showing a typical multilayer oxide scale structure. Although there were differences in oxidation behavior between different grain layers, the thickness of the oxide scale was almost identical, indicating isotropic oxidation resistance. The addition of Si effectively enhanced the oxidation resistance of the composite.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2021)
Article
Nanoscience & Nanotechnology
M. S. Wang, E. W. Liu, Y. L. Du, T. T. Liu, W. H. Liao
Summary: This study investigates the cracking mechanism of SLM-fabricated Ti-48Al-2Cr-2Nb alloy and proposes a novel strategy to eliminate cracks. Experimental results show that a crack-free and high strength alloy can be achieved by eliminating Nb-poor regions and reducing interfaces between different phases. The effectiveness of the proposed strategy is confirmed by the successful fabrication of a nearly alpha(2) single-phase structure in the SLM-fabricated Ti-48Al-2Cr-8Nb alloy.
SCRIPTA MATERIALIA
(2021)
Article
Engineering, Manufacturing
Yu Zhang, Yan Jin Lee, Shuai Chang, Yuyong Chen, Yuchao Bai, Jiong Zhang, Hao Wang
Summary: TiAl intermetallic alloys have attracted attention in aerospace applications due to their low density and superior mechanical properties at high temperatures. However, they are difficult-to-machine materials. This study investigates the machinability of TiAl alloys with different microstructures obtained through heat treatment and evaluates their cutting forces and machined surface roughness. The research provides insights into the deformation mechanisms and plasticity of these alloys during machining.
INTERNATIONAL JOURNAL OF MACHINE TOOLS & MANUFACTURE
(2022)
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
D. Schimbaeck, J. Braun, G. Leichtfried, H. Clemens, S. Mayer
Summary: The study focused on investigating the processability and microstructural features of a powder-based TNM alloy with high Al content, as well as developing a tailored heat treatment to adjust the microstructure for balanced mechanical properties. The research showed that process parameters directly influence the microstructure, and post-processing heat treatment can tailor the microstructure to achieve specific properties.
MATERIALS & DESIGN
(2021)
Article
Engineering, Manufacturing
Danni Huang, Qiyang Tan, Yinghao Zhou, Yu Yin, Feng Wang, Tao Wu, Xianliang Yang, Zhiqi Fan, Yingang Liu, Jingqi Zhang, Han Huang, Ming Yan, Ming-Xing Zhang
Summary: LaB6 nanoparticles were identified as an effective inoculant for LAMed gamma-TiAl alloy, leading to significantly reduced grain size and transformed microstructural morphology. The inoculation treatment not only resulted in crack-free alloy fabrication but also increased compressive yield strength, ultimate strength, and strain to fracture, showing comparable or even better performance than conventionally processed gamma-TiAl alloys.
ADDITIVE MANUFACTURING
(2021)
Article
Chemistry, Physical
M. H. Abbasi, R. Tavakoli, S. G. Shabestari
Summary: The correlation between atomic-scale structure and glass-forming ability of ternary bulk metallic glasses was investigated using molecular dynamics simulation. It was found that the potential energy of the icosahedra reflects the geometric ordering, while the virial stress energy density reveals the chemical ordering. Based on this discovery, a new prediction criterion for glass-forming ability was proposed and validated using experimental data.
Article
Chemistry, Physical
Haimin Zhai, Shuai Cui, Sheng Li, Dongqing He, Bo Cheng, Xinjian Zhang, Wensheng Li, Zhornik Viktor, Uladzimir Seniuts
Summary: Laser shock peening (LSP) treatment significantly affects the phase structure and properties of titanium-based BMG materials, promoting rejuvenation and introducing heterogeneity. This leads to improved plasticity and resistance to crack propagation. LSP-1 specimen exhibits higher hardness and plasticity, reducing fatigue peeling wear caused by brittleness. However, excessive LSP results in increased susceptibility to pitting and significantly reduces tribocorrosion resistance.
Article
Chemistry, Physical
Olga A. Blatova, Maria A. Solodovnikova, Ekaterina M. Egorova, Vladislav A. Blatov
Summary: This study applied a universal geometrical-topological approach to analyze the crystal structures of intermetallic compounds deposited in the Inorganic Crystal Structure Database. By exploring the local atomic configurations, they identified different types of coordination polyhedra and proposed criteria for determining geometric instability. This research provides useful indicators for checking crystallographic information and validating structural models.
Article
Chemistry, Physical
Jose M. Torralba, Diego Iriarte, Damien Tourret, Alberto Meza
Summary: The amount of globally recycled e-waste is less than 20% of the total produced. One of the causes for this low recycling rate is the complex and expensive selective sorting of metals. However, recent research has shown that high entropy alloys (HEAs) can be made from complex alloy mixtures, reducing the dependence on pure critical metals. It has been demonstrated that e-waste can be used to produce competitive HEAs.
Article
Chemistry, Physical
M. Y. He, Y. F. Shen, N. Jia, W. Y. Xue, J. P. Li
Summary: This study successfully improved the mechanical properties of high-entropy alloys (HEAs) through phase decomposition modulation, achieving strengthening of low-cost CuFeMnNi HEAs. The annealed HEAs exhibited excellent mechanical properties, with significantly increased yield strength and maintained satisfactory elongation.
Article
Chemistry, Physical
D. V. Louzguine-Luzgin, F. R. Pratama
Summary: In this study, the growth rate of a crystalline phase in the Al-Fe-Mn-Si metallic glass was measured in real time using transmission electron microscopy. The effective diffusion coefficient related to the slowest diffusing element (Mn) was estimated. The results showed that the growth rate of the crystalline phase was significantly faster compared to pure Al and AlFe compound.
Article
Chemistry, Physical
Zhenhua Han, Yubo Tian, Jun Yang, Jianzhao Li, Jinyang Zhang, Gang Liu, Ran Wei, Guojun Zhang
Summary: In this study, a novel medium-entropy alloy (MEA) (Fe65Ni15Cr10Co10)92Ti5Al3 with a dual heterogeneous structure was developed by adding Ti and Al to a previously reported Fe65Ni15Co10Cr10 MEA. The MEA exhibited ultra-high ultimate tensile strength and work hardening extent at room temperature. The addition of Ti and Al induced precipitation and resulted in a continuous FCC -> BCC martensitic transformation and a transformation-induced plasticity effect. The excellent mechanical properties of the alloy were attributed to the synergistic effects of hetero-deformation induced strengthening, precipitation strengthening, and TRIP.
Article
Chemistry, Physical
S. Y. Liang, L. T. Zhang, B. Wang, Y. J. Wang, E. Pineda, J. C. Qiao
Summary: This study focuses on the influence of the thermomechanical protocol on the aging or rejuvenation of glass by decoupling the thermal and mechanical processes. The results show that Labased metallic glass exhibits material hypomnesia, with a clearer rejuvenation trend observed after imposing increasing amplitude strain oscillations. There is a threshold value of the oscillation amplitude that separates the effects of the protocol into acceleration of aging or rejuvenation. This study reveals the correlation between the thermomechanical properties of metallic glass and the previous application of strain oscillations of various amplitudes, providing an effective tool for regulating the structural state of metallic glasses through a simple-operated method.
Article
Chemistry, Physical
Chihui Liu, Hua Zhang, Qing Wang, Panzhi Wang, Jiadian Yang, Fanchao Meng, Xin Zhou, Lilong Zhu, Shangzhou Zhang, Liang Jiang
Summary: Thermal deformation behavior and microstructure evolution of GH141 alloy were efficiently studied using high-throughput double-cone gradient compression. Different compression temperatures resulted in a wide gradient equivalent strain distribution and gradient microstructure. The dynamic recrystallization mechanism shifted towards discontinuous dynamic recrystallization with increasing compression temperature.
Article
Chemistry, Physical
D. Dubaux, J. Zollinger, M. -C. de Weerd, J. Ghanbaja, S. Mathieu, S. Migot, P. Boulet, S. Sturm, V. Fournee, M. Sicot, J. Ledieu
Summary: We report the formation of large and highly twinned dendrites of the Al13Fe4 approximant phase embedded in an fcc Al-rich matrix. Using a rapid cooling technique, the approximant appears as a 10-fold dendrite. The grain distributions within the arm are complex and a single dendrite arm can contain up to four different orientations. Three types of twins, namely {100}, {001} and {201} twins, have been identified. A growth mechanism involving heteroepitaxial growth from a decagonal Al-Fe quasicrystalline seed is proposed to explain the formation of these specific 10-fold motifs.
Article
Chemistry, Physical
Ming Yang, Yibo Zhang, Jie Dong, Yan Huang, Zhichao Lu, Liang Wang, Xuerui Wei, Zhengdong Fu, Jinkui Zhao, Wenli Song, Wei Li, Yuntao Liu, Dong Ma
Summary: A multi-element microalloying strategy has been used to improve the microstructure and mechanical properties of CuZr-based bulk metallic glass composites. Microalloying effectively refines the CuZr phase and results in finely dispersed B2 crystallites embedded in the BMG matrix, leading to the formation of centimeter-sized BMGCs with good mechanical properties.
Article
Chemistry, Physical
Xuejie Zhu, Xuexi Zhang, Mingfang Qian, Ziyi Wang, Aibin Li, Zongning Chen, Muhammad Imran, Lin Geng
Summary: The homogeneous superelastic behavior in shape memory alloys (SMAs) is crucial for their functional and structural fatigue properties, as well as their stable elastocaloric effect (eCE). In this study, a Ti-22Nb-4Zr-2Ta plate was prepared with a strong recrystallized texture, resulting in a completely recoverable superelastic strain and narrow hysteresis. The observation of strain and temperature evolution revealed the importance of diffuse transformation and favorable texture in achieving mesoscopically homogeneous transformation and related elastocaloric effect.
Article
Chemistry, Physical
Mohammad Navazani, Sitarama Raju Kada, Daniel Fabijanic, Matthew Barnett
Summary: This study investigates the effect of Cu and Al addition on an alloy containing multiple principal elements. The results show that adding small amounts of Cu can improve the alloy's ductility and the hardness of the FCC phase can be predicted using a hybrid model. Unlike previous studies, the corrosion resistance of the alloy is not affected by Cu addition, indicating its potential for further development into a fine-grained stainless steel alloy.
Article
Chemistry, Physical
Fatemeh Azizian, Homam Naffakh-Moosavy, Fatemeh Bagheri
Summary: Novel biodegradable Zn-xCu-0.8Mn-0.4Ag alloys were prepared in this study, and the effects of Cu addition and hot extrusion process on microstructure, mechanical properties, and cytotoxicity of the alloys were investigated. The results showed that adding copper and performing a hot extrusion process can significantly improve the mechanical properties of the alloys, making them potential candidates for cardiovascular stents.
Article
Chemistry, Physical
Ivan A. Ditenberg, Denis A. Osipov, Ivan Smirnov, Konstantin V. Grinyaev
Summary: This study investigates the effect of high-temperature annealing on the structural-phase state and microhardness of Ni3Al samples obtained by spark plasma sintering after high-energy ball milling. The results show that certain annealing temperatures promote grain growth and high-density nucleation, leading to the formation of a fine-grained structural state. The study also analyzes the influence of annealing temperature on the strengthening mechanisms.