Article
Materials Science, Multidisciplinary
Isabella L. M. Costa, Joice Miagava, Ricardo H. R. Castro
Summary: This study proposes that sodium can be used as a dopant to effectively reduce the processing requirements for manufacturing nanoceramics, and successfully produces fully dense transparent sodium-doped magnesium aluminate with grain sizes below 15 nm. The sodium-doped samples exhibit higher indentation fracture toughness compared to undoped samples with similar grain sizes.
Article
Chemistry, Multidisciplinary
Tanna Elyn Rodrigues Fiuza, Marlon Muniz da Silva, Jefferson Bettini, Edson Roberto Leite
Summary: This study conducted in situ experiments using high-resolution transmission electron microscopy (HRTEM) to investigate the sintering process at the nanoscale. The researchers observed a high anisotropic pore elimination and identified the atomic rearrangement and attachment process. The findings contribute to enhancing the kinetic models for the densification process of systems at the nanoscale.
Article
Materials Science, Ceramics
Yan Xiong, Junwei Li, Fansi Luo
Summary: The abnormal grain growth (AGG) behavior was observed during the solid-state sintering of nano-sized BaTiO3 powder. The results challenged traditional sintering theories and proposed an explanation based on the oriented attachment of smaller grains.
CERAMICS INTERNATIONAL
(2022)
Article
Materials Science, Ceramics
Jingxin Yang, Mengying Fu, Qiang Tian, Leichao Meng, Linjing Zhang, Yaqi Liu, Jing Xie, Xinghua Su, Jianhong Peng
Summary: The preparation of Gd2Zr2O7 nanoceramics using a simple and low energy-consuming approach is important due to their wide range of applications. Flash sintering (FS) and two-step flash sintering (TSFS) were used to prepare Gd2Zr2O7 nanoceramics, and the effects of electric field intensity and current limit on densification and grain growth were investigated. TSFS achieved higher relative densities and smaller average grain sizes compared to FS, and the Gd2Zr2O7 nanoceramics exhibited excellent hardness and fracture toughness.
CERAMICS INTERNATIONAL
(2023)
Article
Chemistry, Physical
Dongjiang Zhang, Rui Yu, Xuelei Feng, Xuncheng Guo, Yongkang Yang, Xiqing Xu
Summary: In this study, Al2O3 nanoceramics were synthesized through spark plasma sintering (SPS) of amorphous and polycrystalline powders with similar particle sizes. The sintering processes and resulting products were compared based on the starting powder conditions. The threshold temperature for achieving near-full density of the Al2O3 nanoceramics was found to be 1450°C for polycrystalline powders and 1300°C for amorphous powders. The nanoceramics prepared from amorphous powders exhibited a mean grain size of 170 nm and superior mechanical properties, including high bending strength, Vickers hardness, and fracture toughness. Additionally, they showed larger dynamic strength and dynamic strain compared to those prepared from polycrystalline powders. The toughening mechanism was explained based on the separation of quasi-boundaries.
Article
Chemistry, Physical
Ming Liu, Caochuang Wang, Pengcheng Li, Liang Cheng, Yongming Hu, Yao Xiong, Shishang Guo, Haoshuang Gu, Wanping Chen
Summary: Research on Pt-decorated SnO2 nanoparticles shows promising room-temperature hydrogen-sensing characteristics when pressed into pellets, and the variations in hydrogen-sensing performance after sintering reveal the potential for transforming low-dimensional MOX nanocrystals into bulk materials with improved robustness and comparable room-temperature gas-sensing characteristics.
Article
Chemistry, Physical
Mariusz Drygas, Katarzyna Lejda, Jerzy F. Janik, Klaudia Lyszczarz, Stanislaw Gierlotka, Svitlana Stelmakh, Bogdan Palosz
Summary: The study focused on the preparation of GaN-TiN composite nanocrystalline powders through original precursor solution chemistry, followed by high-pressure and high-temperature sintering processes. Different nitridation temperatures resulted in a pool of composite nanopowders with varying crystallite sizes, while the sintering pressure hindered crystal growth. No evidence of alloying between the two nitrides was found, but nitride domain segregation was observed on a micrometer scale. Vicker's hardness tests showed high hardness values for both composite and individual nanoceramics.
Article
Chemistry, Physical
Mariusz Drygas, Katarzyna Lejda, Jerzy F. Janik, Bogdan Musielak, Stanislaw Gierlotka, Svitlana Stelmakh, Bogdan Palosz
Summary: A study was conducted on the preparation and sintering process of individual and in situ mixed composite nanocrystalline powders of TiN-AlN system, showing that high pressure and high temperature sintering can produce robust nanoceramics with high hardness. Characterization of the powders and nanoceramics revealed the potential for equilibration towards bimetallic compounds and the absence of metastable alloying under the applied synthesis and sintering conditions.
Article
Materials Science, Multidisciplinary
Elijah Borodin, Andrey P. Jivkov, Alexander G. Sheinerman, Mikhail Yu Gutkin
Summary: Designing new ceramic materials with specific thermo-electrical and mechanical properties is crucial for engineering applications. Recent research has shown that incorporating reduced graphene oxide (rGO) in hard ceramic matrix can enhance electrical conductivity and fracture toughness of nano-structured ceramic composites. The properties of these composites depend on the fraction and distribution of rGO inclusions, and a discrete combinatorial strategy utilizing algebraic topology and modern graph theory can be applied to design nano-structured ceramics with a superior balance between conductivity and fracture resistance.
MATERIALS & DESIGN
(2021)
Article
Engineering, Mechanical
Yan Lu, Shengyu Zhu, Xinyu Wang, Xudong Sui, Shuaituo Zhang, Junying Hao, Tong Zhao
Summary: The wear-resistant Ta4HfC5 nanoceramics were prepared using polymer preceramic routes, and their tribological behavior was investigated from room temperature to elevated temperatures. The results showed that the coefficient of friction first increased then decreased with temperature, reaching as low as about 0.20 at 800 degrees C. The low COF at 800 degrees C was mainly attributed to the formation of oxide tribo-film on the worn surface, and the fine microstructure from polymer precursor synthesis had a positive effect on reducing the friction coefficient at high temperatures.
TRIBOLOGY INTERNATIONAL
(2021)
Article
Environmental Sciences
Manee Jindakaraked, Eakalak Khan, Puangrat Kajitvichyanukul
Summary: The biodegradation of paraquat was studied using immobilized microbial cells on nanoceramics made from nanoscale kaolinite. Pseudomonas putida and Bacillus subtilis were immobilized separately on the nanoceramics. The attachment was due to electrostatic force interactions, hydrogen bonding, and covalent bonding between the cells and the support materials. The immobilized cells on the nanoceramics showed a significant removal of paraquat, with approximately 92% removed within 10 hours, compared to only 4% removal by free cells. The nanoceramics also exhibited a decrease in dissolved organic nitrogen, with ICnc-B responsible for 34% degradation and ICnc-P responsible for 22%. Ammonia was identified as the end product of paraquat mineralization.
Article
Materials Science, Ceramics
N. L. Jayalekshmy, Annamma John, Jijimon K. Thomas, Sam Solomon
Summary: In this study, Ln(2)(MO4)(3) (Ln = La and Sm; M = W and Mo) nanomaterials were synthesized using the auto ignited combustion method. The synthesized materials were characterized using various techniques and it was found that they had a monoclinic structure and spherical shape with narrow size distribution. The conductivity studies revealed oxide ion and mixed electron-proton conduction in the prepared materials.
JOURNAL OF THE AUSTRALIAN CERAMIC SOCIETY
(2023)
Article
Chemistry, Physical
Mariusz Drygas, Katarzyna Lejda, Jerzy F. Janik, Svitlana Stelmakh, Bogdan Palosz
Summary: This study presents the synthesis of reaction-mixed nitride nanopowders in the AlN, GaN, and TiN reference system, followed by high-pressure and high-temperature sintering to create novel multi-nitride composite nanoceramics. The process involves refluxing a mixture of metal dimethylamides in hexane, followed by pyrolysis under ammonia to obtain nitride nanopowders. The resulting nanoceramics exhibit high mechanical hardness and can be characterized using XRD, Raman spectroscopy, and SEM/EDX.
Article
Chemistry, Physical
A. M. Habeeb Khan, M. Prabu, Aafiya Khadeeja Khan, T. K. Sreeja
Summary: High performance ferroelectric materials have attracted attention due to their superior dielectric, piezoelectric, and electrostrictive properties. A sol-gel synthesis technique was used to prepare nanoceramics of perovskite Pb (Nbx(Zr0.52Ti0.48)(1-x))O3 (where x = 0, 0.02). X-ray powder diffraction studies confirmed the successful formation of perovskite structure without unwanted pyrochlore phase. The doping of niobium increased relative permittivity and decreased Curie temperature.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Energy & Fuels
Uday Shashikumar, Bikash Chandra Jha, Shashi Chawla, Chaudhery Mustansar Hussain, Gangadhar Andaluri, Yuan-Chung Lin, Vinoth Kumar Ponnusamy
Summary: Nanoceramics have gained significant attention in the scientific community for their wide range of properties and improved energy storage efficiency. They demonstrate exceptional characteristics in the physical, chemical, and mechanical domains, making them a valuable component in composite materials. Nanoceramic composites have shown higher strength retention and enhanced creep characteristics compared to pure ceramics. They have been extensively studied in various applications, including biomedical, wastewater treatment, and energy domains.
