Article
Materials Science, Multidisciplinary
Xin Zhong, Yawen Wang, Yaran Niu, Liping Huang, Qilian Li, Xuebin Zheng
Summary: The study revealed that Yb2O3-rich coatings are beneficial in forming dense apatite layers in CMAS melts, while Yb2Si2O7-rich coatings showed accelerated recession due to an increased fraction of CMAS melts within the reaction layer.
Article
Materials Science, Ceramics
Kristyn Ardrey, Helge Heinrich, Elizabeth Opila
Summary: Yttrium-silicates (Y2Si2O7 and Y2SiO5) are potential environmental barrier coating (EBC) materials for silicon carbide ceramic matrix composites (SiC-CMCs). While their resistance to high temperatures, high-velocity steam, and siliceous debris is well studied, the mechanisms of Na2SO4-induced hot corrosion are not fully understood. This study reveals a previously unknown damage mechanism in which water-soluble Y and Na-Y sulfates and oxysulfates react with Na2SO4, causing significant damage to the yttrium-silicate EBCs materials.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Materials Science, Ceramics
Vito Leisner, Klemens Kelm, Uwe Schulz
Summary: Two thin yttrium silicate-based EBC systems were produced and tested under high temperature conditions. The systems showed satisfactory performance in furnace cycle tests, but one of them exhibited partial delamination. The presence of cracks in the YMS layer provided possible attack paths for water vapor. Rapid water vapor testing demonstrated the protective ability of a thin and phase pure YMS top layer.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2022)
Article
Materials Science, Ceramics
Fan Dong, Zhong Xin, Wang Yawen, Zhang Zhenzhong, Niu Yaran, Li Qilian, Zhang Le, Zheng Xuebin
Summary: The corrosion resistance of X2-RE2SiO5 coatings was better than that of X1-Gd2SiO5 coating due to their phase compositions and stability of crystal structure. After corrosion by CMAS, X1-Gd2SiO5 coating dissolved in CMAS melt and formed apatite phase, while the X2-RE2SiO5 coatings not only formed apatite phase, but also formed garnet phase from reaction of the RE2O3 in the coatings with Al2O3 in CMAS.
JOURNAL OF INORGANIC MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Pingping Liu, Xin Zhong, Yaran Niu, Liping Huang, Hong Li, Dong Fan, Qilian Li, Xuebin Zheng, Jinliang Sun
Summary: This study investigated the reaction behaviors and corrosion mechanisms of tri-layer Yb2SiO5/Yb2Si2O7/Si EBCs against CMAS melts at high temperatures. The results showed that the reaction temperature had a significant impact on the corrosion behaviors of the EBCs, with the Yb2SiO5 top layer exhibiting better corrosion resistance.
Article
Materials Science, Multidisciplinary
Ahmet Hilmi Paksoy, Joao P. Martins, Huatang Cao, Ying Chen, Grant Gibson, Ping Xiao
Summary: The sintering and steam corrosion behavior of Yb2Si2O7 were studied with and without the addition of Al2O3. The addition of Al2O3 significantly improved the sintering of Yb2Si2O7 and also promoted the formation of a thin and dense Yb3Al5O12 protective layer against steam corrosion.
Article
Materials Science, Coatings & Films
Yueh-Cheng Yu, David L. Poerschke
Summary: This study focused on the design of thermal and environmental barrier coatings for Nb-based alloys for high-temperature operation, proposing different multilayer T/EBCs and using mechanics models to analyze thermal stresses and crack formation. Phase equilibria calculations indicated the stability of all combinations at expected use temperatures.
SURFACE & COATINGS TECHNOLOGY
(2022)
Article
Materials Science, Ceramics
Eugenio Garcia, Hector F. Garces, Laura R. Turcer, Hrishikesh Bale, Nitin P. Padture, Sanjay Sampath
Summary: A combination of characterization techniques was used to provide new understanding of the complex crystallization behavior of as-sprayed amorphous Yb2Si2O7-based EBCs. Different phases formed and transformed during crystallization, with an increase in porosity contributing to anomalous expansion. Guidelines for achieving phase-pure and dense EBCs free of vertical cracks are also provided based on this understanding.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2021)
Article
Materials Science, Ceramics
Seung-Hyeon Kim, Nobuo Nagashima, Yoshitaka Matsushita, Byung-Koog Jang
Summary: This study focused on the high-temperature behavior of Gd2Si2O7 interacting with CMAS melt, revealing that the thickness of the reaction layer increased parabolically with heat-treatment time, resulting in the formation of Ca2Gd8(SiO4)6O2 apatite.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2023)
Article
Materials Science, Ceramics
S. Arnal, S. Fourcade, F. Mauvy, F. Rebillat
Summary: The study reports on the corrosion resistance of yttrium silicate coatings with different microstructures in high temperature under different oxidizing environments and demonstrates the significant impact of microstructures on the coating properties. Recommendations for the design of an optimized yttrium silicate EBC with microstructural and compositional variations are proposed based on the findings.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2022)
Article
Materials Science, Ceramics
Liu Pingping, Zhong Xin, Zhang Le, Li Hong, Niu Yaran, Zhang Xiangyu, Li Qilian, Zheng Xuebin
Summary: Rare-earth silicate coatings exhibit good resistance to molten salt corrosion at high temperatures, however, the second phase of Yb2O3 reacts with the molten salt, leading to a shorter service life of the coating.
JOURNAL OF INORGANIC MATERIALS
(2022)
Article
Materials Science, Multidisciplinary
Xueshi Zhuo, Chao Wang, Meng Wang, Jian Wu, Xiaofeng Zhang, Jianlei Cui, Xuesong Mei, Zhengjie Fan
Summary: In this study, a Yb3Al5O12 modified layer was synthesized on the surface of Yb2SiO5 to improve the steam resistance of Si/mullite/Yb2SiO5 Environmental Barrier Coatings. The reaction mechanism of the Al-modified layer was explored and experimental results showed that the modified layer healed defects in the Yb2SiO5 layer, leading to a slower oxidation rate of the Si-bonded coating. Additionally, first-principle molecular dynamics calculations confirmed the excellent steam corrosion resistance of Yb3Al5O12.
Article
Materials Science, Ceramics
Yongqiu Zhang, Binglin Zou, Xiaolong Chen, Xiaolong Cai, Ying Wang, Pai Huang, Ge Yu, Zhengwei Gu
Summary: The study found that at high temperatures, Yb2Si2O7 environmental barrier coatings in molten salt NaVO3 would produce YbVO4 and Yb2SiO5 as the main corrosion products, and their content varied with the corrosion temperature. Furthermore, the amorphous phase in the Yb2Si2O7 coating had a significant impact on the corrosion results.
CERAMICS INTERNATIONAL
(2021)
Article
Materials Science, Ceramics
Qian Guo, Wenting He, Chun Li, Jian He, Jingyong Sun, Hongbo Guo
Summary: Thermal environmental barrier coatings (TEBCs) consisting of three layers were designed to protect ceramic matrix composites (CMCs) from hot gas and steam at 1300℃. The microstructure evolution, interface stability, and oxidation behavior of the coatings were studied, revealing the stable YSH16/YbMS interface and the formation of a reaction zone at the YbMS/Si interface.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Ceramics
Seung-Hyeon Kim, Craig A. J. Fisher, Nobuo Nagashima, Yoshitaka Matsushita, Byung-Koog Jang
Summary: The suitability of sintered erbium disilicate as an environmental barrier coating for gas turbine applications was evaluated through high-temperature corrosion tests with a synthetic CMAS melt. The two materials were found to chemically react and form an apatite phase, with the reaction layer thickness increasing with time.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Ceramics
William D. Summers, David L. Poerschke, Matthew R. Begley, Carlos G. Levi, Frank W. Zok
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2020)
Article
Materials Science, Ceramics
Collin S. Holgate, Gareth G. E. Seward, Andrew R. Ericks, David L. Poerschke, Carlos G. Levi
Summary: This study investigates the dissolution of YSZ into two model silicate melts at different temperatures, providing insights into the dissolution mechanism and its impact on the diffusion rates of Zr4+ and Y3+ in the melts.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2021)
Article
Nanoscience & Nanotechnology
Zhao Wang, Kevin M. Schmalbach, R. Lee Penn, David Poerschke, Antonia Antoniou, Nathan A. Mara, Andreas Stein
Summary: Metal-ceramic nanocomposites exhibit exceptional mechanical properties, with studies showing that 3DOM W-SiOC material demonstrates better plastic deformation at high temperatures.
ACS APPLIED MATERIALS & INTERFACES
(2021)
Article
Materials Science, Multidisciplinary
N. S. Harsha Gunda, Carlos G. Levi, Anton Van der Ven
Summary: The addition of alloying elements to titanium leads to short-ranged repulsive interactions with interstitial oxygen, likely due to accumulation of charge and misfit strains. A unique hybridization between dissolved substitutional elements and interstitial oxygen within hcp Ti is identified, resulting in a repulsive interaction at short distances.
PHYSICAL REVIEW MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
David L. Poerschke
Summary: This article reviews recent advances in thermodynamic models and databases for predicting reactions between ingested debris and coating materials, as well as developments in modeling approaches to capture key features of debris and deposits behavior, their interaction with environmental barrier coatings, and reactions during infiltration into thermal barrier coatings.
Article
Materials Science, Ceramics
Eeshani Godbole, Anette von der Handt, David Poerschke
Summary: This study investigates the influence of rare earth ion radius on the stability and extent of the garnet solid solution phase. Results show a reduction in stability of silicate garnet with increasing rare earth ion radius. Different rare earth systems exhibit varied phases formation, but the extent of the garnet solid solution only slightly increases compared to apatite stability.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Materials Science, Ceramics
Andrew R. Ericks, Frank W. Zok, David L. Poerschke, Carlos G. Levi
Summary: This study presents a protocol for selecting representative silicate compositions for comparative testing of gas turbine coating materials. The protocol involves converting compositions of engine deposits and naturally occurring siliceous debris into the five major oxides and further refining them using principal component analysis and k-means clustering. The process results in four classes of possible deposits with common chemical characteristics. Key thermophysical properties of these deposits are calculated and related to the glass network connectivity. Finally, the reactions of deposits from each class with typical thermal and environmental barrier oxides are compared, considering the composition variations within each deposit class.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2022)
Article
Materials Science, Coatings & Films
Yueh-Cheng Yu, David L. Poerschke
Summary: This study focused on the design of thermal and environmental barrier coatings for Nb-based alloys for high-temperature operation, proposing different multilayer T/EBCs and using mechanics models to analyze thermal stresses and crack formation. Phase equilibria calculations indicated the stability of all combinations at expected use temperatures.
SURFACE & COATINGS TECHNOLOGY
(2022)
Article
Materials Science, Multidisciplinary
Atharva S. Chikhalikar, Eeshani P. Godbole, David L. Poerschke
Summary: This study analyzes the behavior of oxide-sulfate deposits under different compositions and temperatures using experiments and computational models. The results show that mixed-cation deposits accelerate sulfate decomposition and that reaction pathways forming ternary and quaternary silicates are faster than those forming binary reaction products. Additionally, multi-cation mixtures can suppress the evaporation of sodium and potassium sulfates, allowing the sulfate-bearing liquid to remain at higher temperatures.
Article
Materials Science, Multidisciplinary
Atharva S. Chikhalikar, Eeshani P. Godbole, David L. Poerschke
Summary: This study develops an automated protocol for analyzing and comparing the effects of three deposits on the accelerated non-uniform degradation of a model alloy at high temperature. The Ca-containing mixed oxide deposit increases oxide intrusions into the alloy, while the CaSO4 and Ca-containing mixed sulfate deposits form less-protective calcium aluminates and increase the roughness of the alloy-TGO interface. The mixed sulfate deposit melts and spreads, resulting in more uniform attack.
Article
Materials Science, Ceramics
Yueh-Cheng Yu, Eeshani P. Godbole, Josselyne Berrios, Nethmi Hewage, David L. Poerschke
Summary: Mixtures of rare-earth zirconates and aluminates with Y or Y + Gd exhibit slower sintering compared to pure fluorite at 1400 degrees C. A Gd-containing composition that forms a perovskite aluminate instead of garnet shows faster densification after garnet decomposition. At 1500 degrees C, the Y-free sample shows the fastest initial sintering rate, while the samples containing Y + Gd have varying sintering rates. The equimolar Y + Gd zirconate-aluminate exhibits the slowest densification and retains approximately 25% porosity after 250 h.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Materials Science, Ceramics
Eeshani P. Godbole, Nethmi Hewage, David L. Poerschke
Summary: Thermal and environmental barrier coatings need to resist attack from CMFAS deposits and produce uniform reaction layers. The reactions of four coating compositions in the AlO1.5-REO1.5-ZrO2 systems with three model CMFAS deposits were studied. Coating materials with higher AlO1.5 content produced uniform reaction layers, while the most SiO2-rich CMFAS was most likely to produce a non-uniform response.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2023)
Article
Materials Science, Ceramics
Yueh-Cheng Yu, William O. O. Nachlas, David L. L. Poerschke
Summary: This study investigated the stability limits of rare earth aluminates containing mixtures of RE cations. It was found that it is difficult to form equimolar mixed-RE aluminates, as the RE ions selectively partition into specific phases based on size trends. These results are important for understanding phase stability, cation partition trends, and potential applications.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2023)
Article
Materials Science, Ceramics
Eeshani P. Godbole, Nethmi Hewage, Anette von der Handt, David L. Poerschke
Summary: The durability of T/EBCs exposed to CMAS deposits depends on the nature of reactions between the coatings and deposits, which consume the melt and can block porosity. This study compares the efficiency of reaction products reported in the literature to those formed on four prospective T/EBC materials. The results show that adding aluminates to zirconate materials promotes the crystallization of garnet, cuspidine, and apatite, but reduces reaction efficiency compared to single phase zirconates.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2023)
Article
Materials Science, Multidisciplinary
Y. Liu, K. Zweiacker, C. Liu, J. T. McKeown, J. M. K. Wiezorek
Summary: The evolution of rapid solidification microstructure and solidification interface velocity of hypereutectic Al-20at.%Cu alloy after laser melting has been studied experimentally. It was found that the formation of microstructure was dominated by eutectic, alpha-cell, and banded morphology grains, and the growth modes changed with increasing interface velocity.
Article
Materials Science, Multidisciplinary
Bharat Gwalani, Julian Escobar, Miao Song, Jonova Thomas, Joshua Silverstein, Andrew Chihpin Chuang, Dileep Singh, Michael P. Brady, Yukinori Yamamoto, Thomas R. Watkins, Arun Devaraj
Summary: Castable alumina forming austenitic alloys exhibit superior creep life and oxidation resistance at high temperatures. This study reveals the mechanism behind the enhanced creep performance of these alloys by suppressing primary carbide formation and offers a promising alloy design strategy for high-temperature applications.
Article
Materials Science, Multidisciplinary
Jian Song, Qi Zhang, Songsong Yao, Kunming Yang, Houyu Ma, Jiamiao Ni, Boan Zhong, Yue Liu, Jian Wang, Tongxiang Fan
Summary: Recent studies have shown that achieving an atomically flat surface for metals can greatly improve their oxidation resistance and enhance their electronic-optical applications. Researchers have explored the use of graphene as a covering layer to achieve atomically flat surfaces. They found that high-temperature deposited graphene on copper surfaces formed mono-atomic steps, while annealed copper and transferred graphene on copper interfaces formed multi-atomic steps.
Article
Materials Science, Multidisciplinary
Jennifer A. Glerum, Jon-Erik Mogonye, David C. Dunand
Summary: Elemental powders of Al, Ti, Sc, and Zr are blended and processed via laser powder-bed fusion to create binary and ternary alloys. The microstructural analysis and mechanical testing show that the addition of Ti results in the formation of primary precipitates, while the addition of Sc and Zr leads to the formation of fine grain bands. The Al-0.25Ti-0.25Zr alloy exhibits comparable strain rates to Al-0.5Zr at low stresses, but significantly higher strain rates at higher stresses during compressive creep testing. Finite element modeling suggests that the connectivity of coarse and fine grain regions is a critical factor affecting the creep resistance of the alloys.
Article
Materials Science, Multidisciplinary
P. Jannotti, B. C. Hornbuckle, J. T. Lloyd, N. Lorenzo, M. Aniska, T. L. Luckenbaugh, A. J. Roberts, A. Giri, K. A. Darling
Summary: This work characterizes the thermo-mechanical behavior of bulk nanocrystalline Cu-Ta alloys under extreme conditions. The experiments reveal that the alloys exhibit unique mechanical properties, behaving differently from conventional nanocrystalline Cu. They do not undergo grain coarsening during extrusion and exhibit behavior similar to coarse-grained Cu.
Article
Materials Science, Multidisciplinary
Yiqing Wei, Jingwei Li, Daliang Zhang, Bin Zhang, Zizhen Zhou, Guang Han, Guoyu Wang, Carmelo Prestipino, Pierric Lemoine, Emmanuel Guilmeau, Xu Lu, Xiaoyuan Zhou
Summary: This study proposes a new strategy to modify microstructure by phase regulation, which can simultaneously enhance carrier mobility and reduce lattice thermal conductivity. The addition of Cu in layered SnSe2 induces a phase transition that leads to increased grain size and reduced stacking fault density, resulting in improved carrier mobility and lower lattice thermal conductivity.
Article
Materials Science, Multidisciplinary
Jia Chen, Zhengyu Zhang, Eitan Hershkovitz, Jonathan Poplawsky, Raja Shekar Bhupal Dandu, Chang-Yu Hung, Wenbo Wang, Yi Yao, Lin Li, Hongliang Xin, Honggyu Kim, Wenjun Cai
Summary: In this study, the structural origin of the pH-dependent repassivation mechanisms in multi-principal element alloys (MPEA) was investigated using surface characterization and computational simulations. It was found that selective oxidation in acidic to neutral solutions leads to enhanced nickel enrichment on the surface, resulting in reduced repassivation capability and corrosion resistance.
Article
Materials Science, Multidisciplinary
X. Y. Xu, C. P. Huang, H. Y. Wang, Y. Z. Li, M. X. Huang
Summary: The limited slip systems of magnesium (Mg) and its alloys hinder their wide applications. By conducting tensile straining experiments, researchers discovered a rate-dependent transition in the dislocation mechanisms of Mg alloys. At high strain rates, glissile dislocations dominate, while easy-glide dislocations dominate at low strain rates. Abundant glissile dislocations do not necessarily improve ductility.
Article
Materials Science, Multidisciplinary
M. S. Szczerba, M. J. Szczerba
Summary: Inverse temperature dependences of the detwinning stress were observed in face-centered cubic deformation twins in Cu-8at.%Al alloy. The detwinning stress increased with temperature when the pi detwinning mode was involved, but decreased when the pi/3 mode was involved. The dual effect of temperature on the detwinning stress was due to the reduction of internal stresses pre-existing within the deformation twins. The complete reduction of internal stresses at about 530 degrees C led to the equivalence of the critical stresses of different detwinning modes and a decrease in the yield stress anisotropy of the twin/matrix structure.
Article
Materials Science, Multidisciplinary
Taowen Dong, Tingting Qin, Wei Zhang, Yaowen Zhang, Zhuoran Feng, Yuxiang Gao, Zhongyu Pan, Zixiang Xia, Yan Wang, Chunming Yang, Peng Wang, Weitao Zheng
Summary: The interaction between the electrode and the electric double layer (EDL) significantly influences the energy storage mechanism. By studying the popular alpha-Fe2O3 electrode and the EDL interaction, we find that the energy storage mechanism of the electrode can be controlled by modulating the EDL.
Article
Materials Science, Multidisciplinary
Matthew R. Barnett, Jun Wang, Sitarama R. Kada, Alban de Vaucorbeil, Andrew Stevenson, Marc Fivel, Peter A. Lynch
Summary: The elastic-plastic transition in magnesium alloy Mg-4.5Zn exhibits bursts of deformation, which are characterized by sudden changes in grain orientation. These bursts occur in a coordinated manner among nearby grains, with the highest burst rate observed at the onset of full plasticity. The most significant burst events are associated with twinning, supported by the observation of twinned structures using electron microscopy. The bursts are often preceded and followed by a stasis in peak movement, indicating a certain "birth size" for twins upon formation and subsequent growth at a later stage.
Article
Materials Science, Multidisciplinary
Vaidehi Menon, Sambit Das, Vikram Gavini, Liang Qi
Summary: Understanding solute segregation thermodynamics is crucial for investigating grain boundary properties. The spectral approach and thermodynamic integration methods can be used to predict solute segregation behavior at grain boundaries and compare with experimental observations, thus aiding in alloy design and performance control.
Article
Materials Science, Multidisciplinary
Feiyu Qin, Lei Hu, Yingcai Zhu, Yuki Sakai, Shogo Kawaguchi, Akihiko Machida, Tetsu Watanuki, Yue-Wen Fang, Jun Sun, Xiangdong Ding, Masaki Azuma
Summary: This study reports on the negative and zero thermal expansion properties of Cd2Re2O7 and Cd1.95Ni0.05Re2O7 materials, along with their ultra-low thermal conductivity. Through investigations of their structures and phonon calculations, the synergistic effect of local structure distortion and soft phonons is revealed as the key to achieving these distinctive properties.
Article
Materials Science, Multidisciplinary
Thomas Beerli, Christian C. Roth, Dirk Mohr
Summary: A novel testing system for miniature specimens is designed to characterize the plastic response of materials for which conventional full-size specimens cannot be extracted. The system has an automated operation process, which reduces the damage to specimens caused by manual handling and improves the stability of the test results. The experiments show that the miniature specimens extracted from stainless steel and aluminum have high reproducibility, and the results are consistent with those of conventional-sized specimens. A correction procedure is provided to consider the influence of surface roughness and heat-affected zone caused by wire EDM.
Article
Materials Science, Multidisciplinary
Rani Mary Joy, Paulius Pobedinskas, Nina Baule, Shengyuan Bai, Daen Jannis, Nicolas Gauquelin, Marie-Amandine Pinault-Thaury, Francois Jomard, Kamatchi Jothiramalingam Sankaran, Rozita Rouzbahani, Fernando Lloret, Derese Desta, Jan D'Haen, Johan Verbeeck, Michael Frank Becker, Ken Haenen
Summary: This study investigates the influence of film microstructure and composition on the Young's modulus and residual stress in nanocrystalline diamond thin films. The results provide insights into the mechanical properties and intrinsic stress sources of these films, and demonstrate the potential for producing high-quality nanocrystalline diamond films under certain conditions.
