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Microstructure, Mechanical and Ablation Properties of Transpiration cooling Applied to c/c-Sic composite for Novel Anti-ablation Material

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APPLIED cOMPOSITE MATERIALS 2022年第6期29卷 2147-2163页

作者： Wang, Pei Guo, Yonggang Du, Sanming Jia, Yunchao Zhang, Hongbo Yin, Jian Henan Univ Technol Sch Mat Sci & Engn Zhengzhou 450001 Peoples R China Henan Univ Technol Sch Mech Engn Zhengzhou 450001 Peoples R China Henan Univ Sci & Technol Natl United Engn Lab Adv Bearing Tribol Luoyang 471000 Peoples R China Cent South Univ State Key Lab Power Met Changsha 410083 Peoples R China

Taking the advantages of porous ceramic (c/c-Sic composite) and transpiration cooling (copper alloy), c/c-Sic-cu composite was fabricated to attain a novel anti-ablation material for high temperature structure application of aerospace systems, via chemical vapor deposition and infiltration technologies. The effects of Sic content on microstructure, thermal conductivity, mechanical and ablation properties of c/c-Sic-cu composite were investigated. As the Sic content increases from 0 vol% to 25.12 vol%, thermal conductivity, flexural strength and ablation resistance are improved by 84.99%, 78.76% and 53.68%, respectively. Thermal conductivity and thermal diffusivity exhibit proportional linear correlation with Sic content. The high Sic content could shorten the yield stage and increase the breaking strength during the flexural fracture process. When the Sic content is 25.12 vol%, the formation continuous and compact anti-ablation (SiO2) layer is formed by oxidizing and melting fluidity processes during oxyacetylene ablation test, and the protective layer covers the ablation surface and slows down the oxidative ablation, which combines with the transpiration cooling effect of copper alloy to further improve ablation resistance of c/c-Sic-cu composite.

关键词： c c-Sic-cu composite chemical vapor deposition Transpiration cooling Ablation property

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Time-dependent creep fatigue damage evolution in c/Sic composite: Theory and analytical prediction

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cERAMIcS INTERNATIONAL 2022年第14期48卷 20731-20742页

作者： Li, Longbiao Reynaud, Pascal Fantozzi, Gilbert Nanjing Univ Aeronaut & Astronaut Coll Civil Aviat 29 Jiangjun Ave Nanjing 211106 Peoples R China Univ Lyon INSA Lyon MATEIS UO CNRS 5510 7 Ave Jean Capelle Villeurbanne Cedex F-69621 Lyon France

In this paper, the time-dependent damage evolution in carbon fiber-reinforced silicon carbide ceramic-matrix composites (c/Sic cMcs) under creep fatigue loading at elevated temperature was analyzed using a micromechanical approach. Synergistic effects of creep fatigue peak stress level and damage in the matrix and the interface on time-dependent damage evolution in c/Sic composites were analyzed. Next, relationships of timedependent creep fatigue damage mechanisms, damage parameters, environmental temperature and duration were determined. Then, the effects of composite constituent properties, creep fatigue damage state, environmental temperature, and duration on time-dependent damage evolution in c/Sic composites were analyzed. Furthermore, time-dependent composite strain response and interface debonding and oxidation state in c/Sic composite under different creep fatigue peak stress levels were predicted. Under creep fatigue loading, the composite internal damage evolution contributed to the increased time/temperature-dependent composite peak strain. Hysteresis-based damage parameters were developed and utilized to monitor c/Sic composite internal damage evolution. Under creep fatigue loading, the hysteresis area and width increased with oxidation duration to a peak value and remained constant, and the hysteresis modulus decreased with oxidation duration.

关键词： c Sic creep fatigue Damage evolution Time -dependent Interface debonding Matrix cracking

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Ablation behavior of thin-blade co-deposited c/cx-Sicy composites under the influence of the complex fluid conditions of the oxyacetylene torch

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cERAMIcS INTERNATIONAL 2022年第12期48卷 16923-16932页

作者： Liu, Ningkun Guo, Lingjun Kou, Gang Li, Yunyu Yin, Xuemin Northwestern Polytech Univ Shaanxi Key Lab Fiber Reinforced Light Composite M Xian 710072 Peoples R China

This paper offers a new way of testing the ablation property of material under an oxyacetylene torch using a thinblade specimen, which costs much less time to reach the maximum temperature and provides a harsh turbulence fluid field that's closer to reality. The thin-blade specimen experiences a higher turbulent intensity than the traditional disk-like specimen, leading to more efficient heat exchange. The fluid field simulation agrees with the testing results. In addition, we manage to synthesize the c/cx-Sicy composites with the co-deposition chemical vapor infiltration (cVI) method. The c/cx-Sicy composites exhibit a similar anti-ablation property as c/c composites and consist of enough Sic phase simultaneously, combining the advantages of both c/c composites and c/Sic composites. The thin-blade c/cx-Sicy composites show a lower linear ablation rate (1.6 mu m/s) than c/ c composites (4.1 mu m/s) and c/Sic composites (19.6 mu m/s) during the oxyacetylene test. The glass layer formed on the surface of c/cx-Sicy could cling to the bulk material instead of peeling off due to the high Pyc content in the matrix could protect the SiO2 from blowing away.

关键词： Ablation Antioxidation c c composites Thin blade computational fluid dynamics

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Oxidation protection of B4c modified HfB2-Sic coating for c/c composites at 1073-1473 K

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cERAMIcS INTERNATIONAL 2022年第3期48卷 3206-3215页

作者： Wang, Peipei Zhang, Menglin Sun, Wanchang Ren, Xuanru Xian Univ Sci & Technol Coll Mat Sci & Engn Xian 710054 Shaanxi Peoples R China China Univ Min & Technol Coll Mat Sci & Engn Xuzhou 221116 Jiangsu Peoples R China

B4c modified HfB2-Sic coating for c/c substrate was designed to expand the application of HfB2-Sic based coating in low-medium temperature environment. The oxidation protection behavior of HfB2-Sic based ceramic coatings with and without B4c at 1073, 1273 and 1473 K was tested and analyzed. The experimental results reveal that the oxidative damage of HfB2-Sic coated c/c reduces by over 20% after introducing B4c, which may be due to the protection of borosilicate glass with more suitable viscosity during oxidation. Meanwhile, B4c can improve the oxidation protection ability of HfB2-Sic coating best at 1473 K. And the introduction of B4c can reduce the mass loss of HfB2-Sic coated c/c sample by 77.6% after oxidation for 58 h at 1473 K. The fluidity of glass film becoming better with temperature-rising, and the fluid borosilicate glass layer makes the coated samples have the best anti-oxidation properties at 1473 K among these three temperatures.

关键词： Oxidation protection HfB2-Sic-B4c coating c c substrate Glass film

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Preparation and characterization of monolayer oxidation resistant coating on c/Sic composites

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cERAMIcS INTERNATIONAL 2022年第16期48卷 23731-23739页

作者： Fan, Xizhi Huang, Wenzhi Mao, Weiguo Zhou, Zhe Zhang, Long Zhou, Xin Changsha Univ Sci & Technol Sch Mat Sci & Engn Changsha 410114 Peoples R China Natl Univ Def Technol Coll Aerosp Sci & Engn Sci & Technol Adv Ceram Fibers & Composites Lab Changsha 410073 Peoples R China Yantai Univ Inst Adv Studies Precis Mat Yantai 264005 Peoples R China

Ba0.25Sr0.75Al2Si2O8 (BSAS), Yb2SiO5 and Y2SiO5 are widely deposited as the main phase of composite coatings or as the functional layer in multilayer coatings. The investigation of monolayer coating can not only broaden the application of monolayer anti-oxidation coating, but also be an important basis for the design of multilayer and composite coatings. Monolayer BSAS, Yb2SiO5 and Y2SiO5 coatings were deposited on c/Sic composite by atmospheric plasma spraying (APS). Thermal physics and chemical properties, microstructure, bond stability and oxidation protection of the monolayer coatings were investigated. The results showed that the monolayer coating effectively improved the oxidation resistance of c/Sic composite. The microstructure and mechanical properties of the coatings play an important role in the bond stability and oxidation resistance of the coated sample. Among the tested coatings, the Y2SiO5 coating exhibited excellent mechanical properties and compact structure, which resulted in the highest bond stability and the best protection.

关键词： c Sic composite Monolayer coating Bond stability Oxidization resistance Atmospheric plasma spraying

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A new method to improve the laser-ablation resistance of Si-Sic coating on c/c composites: Laser cladding

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JOURNAL OF THE EUROPEAN cERAMIc SOcIETY 2022年第14期42卷 6425-6434页

作者： Teng, Liu Shi, Xiao-Hong Wang, Han-Hui Li, Wei Yin, Xue-Min Li, He -Jun Northwestern Polytech Univ Shaanxi Prov Key Lab Fiber Reinforced Light Compos Xian 710072 Shaanxi Peoples R China

New method to prepare Si-Sic coating on c/c composites by laser cladding (Lc-Si-Sic) was established to improve the laser ablation resistance of the coating. Results showed that the Lc-Si-Sic coating had lower roughness, better mechanical properties and superior laser-ablation resistance compared with the Si-Sic coating fabricated by the traditional coating preparation process: pack cementation (Pc-Si-Sic). Due to the shorter heat treatment and less Si infiltration, the flexural strength of the Lc-Si-Sic coated sample was 111.32 MPa, which was 144% higher than that of the Pc-Si-Sic coated sample. confirmed by finite element simulation, the Lc-Si-Sic coating exhibited better laser-ablation resistance because of the "sweating cooling" mechanism. Under 23.89 MW center dot m � 2 ablation for 7 s, the surface temperature of the Lc-Si-Sic coated sample was 3046 K, which was 157 K lower than that of the Pc-Si-Sic, causing the mass loss rate of the Lc-Si-Sic coating (0.10%) was only 45.45% of the Pc-Si-Sic coating.

关键词： c c composites Laser cladding Pack cementation Laser -ablation Mechanical properties

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Experiment-based numerical evaluation of the surface recession of c/c-Sic composites under the high-energy laser

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cERAMIcS INTERNATIONAL 2022年第23期48卷 34550-34563页

作者： Ge, Jian Li, Wei chao, Xujiang Wang, Hanhui Wang, Zhaowei Qi, Lehua Northwestern Polytech Univ Sch Mech Engn Xian 710072 Shaanxi Peoples R China Northwestern Polytech Univ Shaanxi Prov Key Lab Fiber Reinforced Light Compos Xian 710072 Shanxi Peoples R China China Acad Launch Vehicle Technol Beijing 100076 Peoples R China

In this paper, we developed a multi mechanism coupling finite element model to predict the surface recession of c/c-Sic composites on the basis of the ablation phenomena. In particular, we took into account temperaturedependent properties of component materials, heat convection, and radiation in the ultra-high temperature range. By combining a user-defined subroutine and arbitrary Lagrangian-Eulerian adaptive meshing technique, the surface recession of c/c-Sic composites was captured. The predicted ablation depth agreed well with experimental results. The trend of the ablation rate between simulations and experiments was almost the same. Meanwhile, the effects of the laser powers on ablation behaviors of c/c-Sic composites were investigated. It was found that low laser powers had little effect on the ablation rate while the ablation rate increased first and then decreased for high laser powers.

关键词： c c-Sic composites Thermal properties Finite element analysis Surface recession

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Nanoplastics cause transgenerational toxicity through inhibiting germline microRNA mir-38 in c. elegans

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JOURNAL OF HAZARDOUS MATERIALS 2022年 437卷 129302页

作者： Hua, Xin Zhao, Yue Yuan, Yujie Zhang, Le Bian, Qian Wang, Dayong Southeast Univ Med Sch Key Lab Environm Med Engn Minist Educ Nanjing 210009 Peoples R China Jiangsu Prov Ctr Dis Control & Prevent Inst Toxicol & Risk Assessment Nanjing 210009 Peoples R China Shenzhen Ruipuxun Acad Stem Cell & Regenerat Med Shenzhen 518122 Peoples R China

Nanoplastic exposure potentially caused the induction of transgenerational toxicity. Nevertheless, the molecular basis for nanoplastic exposure-induced transgenerational toxicity remains largely unclear. Using caenorhabditis elegans as an animal model, we examined the role of germline microRNA (miRNA) mir-38 in regulating the transgenerational toxicity of polystyrene nanoparticles (PS-NPs). After the exposure, 1-100 mu g/L PS-NP decreased expression of germline mir-38. Meanwhile, germline mir-38 overexpression conferred a resistance to transgenerational PS-NP toxicity, which suggested that the decrease in germline mir-38 mediated the induction of transgenerational PS-NP toxicity. In the germline, mir-38 regulated transgenerational PS-NP toxicity by inhibiting activity of downstream targets (NDK-1, NHL-2, and WRT-3). Among these three downstream targets, germline NDK-1 further controlled transgenerational PS-NP toxicity by suppressing the function of KSR-1/2, two kinase suppressors of Ras. Therefore, in the germline, the decrease in mir-38 mediated induction of trans generational PS-NP toxicity by at least inhibiting signaling cascade of NDK-1-KSR-1/2 in nematodes. The findings in this study are helpful for providing relevantly molecular endpoints to assess potential transgenerational toxicity of nanoplastics.

关键词： Nanoplastics Germline mir-38 Transgenerational toxicity c elegans

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Influence of the fiber orientation on 3D c/c-Sic composite material and its formation mechanism of the machining surface

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INTERNATIONAL JOURNAL OF ADVANcED MANUFAcTURING TEcHNOLOGY 2022年第7-8期118卷 2725-2743页

作者： Li, Wei Long, Gui Shi, Feng Zhou, Shenlei Yin, Jia Yang, Jun Hunan Univ Coll Mech & Vehicle Engn Changsha 410082 Hunan Peoples R China Hunan Univ Natl Engn Technol Res Ctr High Efficiency Grindin Changsha 410082 Hunan Peoples R China Natl Univ Def Technol Coll Intelligent Sci Changsha 410073 Hunan Peoples R China Chinese Acad Sci Shanghai Inst Opt & Fine Mech Shanghai 201800 Peoples R China

carbon/carbon (c/c)-Sic composite materials attained much attention due to its unique properties like immense thermal conductivity, high corrosion, and abrasive resistance. Few scholars have systematically studied the grinding machinability of 3D c/c-Sic composite material. In this paper, the grinding experiment of 3D c/c-Sic composite material was carried out with a resin-bonded diamond grinding wheel. The effect of machining conditions on the grinding force, micromorphology, surface quality, and residual stress was studied, and the material removal mechanism was analyzed in-depth aimed at the three typical fiber orientations. The result shows that the surface roughness of different fiber areas follows the order: 90 degrees fiber > 0 degrees fiber > Normal fiber. The fiber's orientation showed a significant effect on the mechanism of material removal. The residual thermal stress of c/c-Sic composite material increases from 32.25 to 207.43 MPa during the grinding process. Polishing the ground surface not only can remove the crack layer and residual stress layer but also can introduce residual compressive stress layer, which can effectively enhance the material strength. The 3D c/c-Sic composite material removal process is distinct from the composite material 2D c/c-Sic and the traditional brittle material. The main removal of c/c-Sic composite material is recognized as brittle fracture mode. Because of the different mechanical properties of carbon fiber, Sic matrix, and the pyrocarbon interface, the damage of material during grinding is asynchronous. The present work provides a comprehensive understanding for processing 3D c/c-Sic composite material parts with high quality.

关键词： c c-Sic Grinding carbon fiber Surface roughness The material removal mechanism

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Ablation mechanism of c/c-Sic and c/c-Sic-Zrc composites in hypersonic oxygen-enriched environment

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cERAMIcS INTERNATIONAL 2022年第16期48卷 22985-22993页

作者： Gao, Yong Zha, Bai-Lin Wang, Jin-Jin Sun, Zhen-Sheng Zhang, Zhao-Fu Shi, Yi-Ang Rocket Force Univ Engn Xian 710025 Peoples R China Xian Aerosp Composites Res Inst Xian 710025 Peoples R China Project Management Ctr Beijing 100085 Peoples R China 2 Tongxin Rd Xian Peoples R China

In this study, c/c-Sic and c/c-Sic-Zrc composites were prepared via chemical vapor infiltration and polymer infiltration pyrolysis, and the ablation mechanism under hypersonic oxygen-rich environmental conditions was investigated. The c/c-Sic composites demonstrate an excellent ablation resistance in a hypersonic oxygen-rich environment with a relatively low temperature and speed of approximately 1800 K and 1100 m/s, respectively. It is only in the ablation center area with higher temperatures that a certain degree of thermochemical ablation was observed. The mass and linear ablation rates of c/c-Sic composites (0.027 g/s and 0.117 mm/s, respectively) showed a significant increase in a hypersonic oxygen-rich environment with a temperature and velocity of approximately 2050 K and 2000 m/s, respectively. The high-temperature ablation resistance of Zrc-modified c/ c-Sic-Zrc composites improved significantly. However, the Zrc ceramic component had a considerable impact on the ablation resistance of the material. The structural integrity of c/c-20Sic-30Zrc composites was relatively high in hypersonic oxygen-rich environments with a jet temperature and velocity of 2050 K and 2000 m/s, respectively, and mass and linear ablation rates were 0.012 g/s and 0.015 mm/s, respectively. When the Zrc content increased by 40%, the ablation resistance of the composite reduced significantly, whereas the mass and linear ablation rates increased to 0.043 g/s and 0.130 mm/s, respectively.

关键词： c c-Sic composites Hypersonic Oxygen-enriched ablation Ablation mechanism

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