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Tensile Mechanical Behavior and Failure Mechanism of a Plain-Woven SiCf/SiC Composites at Room and Elevated Temperatures

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Journal of Materials Science and Chemical Engineering 2024年第4期12卷 67-83页

作者： Jianze He Xuefeng Teng Xiao’an Hu Xiao Luo Qi Zeng xueqiang cao School of Aircraft Engineering Nanchang Hangkong University Nanchang China Jiangxi Key Laboratory of Micro Aeroengine Nanchang China Hunan Aviation Powerplant Research Institute Aero Engine Corporation of China Zhuzhou China State Key Laboratory of Silicate Profound Building Materials Wuhan University of Technology Wuhan China

Ceramic matrix composites (CMCs) are the preferred materials for solving advanced aerospace high-temperature structural components;it has the comprehensive advantages of higher temperature (~1500˚C) and low density. In service environments, CMCs exhibit complex damage mechanisms and failure modes, which are affected by constituent materials, meso-architecture and inhere defects. In this paper, the in-plane tensile mechanical behavior of a plain-woven SiCf/SiC composite at room and elevated temperatures was investigated, and the factors affecting the tensile strength of the material were discussed in depth. The results show that the tensile modulus and strength of SiCf/SiC composites at high temperature are lower, but the fracture strain increases and the toughness of the composites is enhanced;the stitching holes significantly weaken the tensile strength of the material, resulting in the material is easy to break at the cross-section with stitching holes.

关键词： Plain-Woven SiCf/SiC Composites Damage and Failure Analysis Stitching Hole

铝含量对镍铝合金在稀硫酸溶液中的腐蚀行为影响

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中国腐蚀与防护学报 2024年第4期44卷 1011-1021页

作者：杜广芦国强邓龙辉蒋佳宁曹学强武汉理工大学硅酸盐建筑材料国家重点实验室武汉430070 中国航发沈阳黎明航空发动机有限责任公司沈阳110043

镍基高温合金(NiCrAlY)常用于航空发动机的热端部件。热端部件如燃烧室、导向叶片和动叶片需要热障涂层(TBCs)保护。TBCs由抗氧化的金属粘结层(BC)和起隔热作用的陶瓷层(TC)组成。BC材料也是NiCrAlY合金,其Al和Cr含量比NiCrAlY基体高许... 详细信息

镍基高温合金(NiCrAlY)常用于航空发动机的热端部件。热端部件如燃烧室、导向叶片和动叶片需要热障涂层(TBCs)保护。TBCs由抗氧化的金属粘结层(BC)和起隔热作用的陶瓷层(TC)组成。BC材料也是NiCrAlY合金,其Al和Cr含量比NiCrAlY基体高许多,导致BC的腐蚀电位比基体低53mV,BC发生电偶腐蚀。本文采用了不同Al含量的NiAl合金,研究Al含量对NiAl合金在稀H_(2)SO_(4)中腐蚀行为的影响。研究表明,Ni95Al5的腐蚀电位最高,腐蚀电流密度最小;Ni_(75)Al_(25)腐蚀电位较低。研究证明,BC中Al含量高是导致BC在自然环境下发生腐蚀的原因。

关键词： NiAl合金稀硫酸电化学行为腐蚀产物

Application of Rare Earths in Thermal Barrier Coating Materials

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Journal of Materials Science & Technology 2007年第1期23卷 15-35页

作者： xueqiang cao Key Lab of Rare Earth Chemistry and Physics Changchun Institute of Applied Chemistry Chinese Academy of Sciences.Changchun 130022 China

Rare earths are a series of minerals with special properties that make them essential for applications including miniaturized electronics, computer hard disks, display panels, missile guidance, pollution controlling catalysts, H2-storage and other advanced materials. The use of thermal barrier coatings （TBCs） has the potential to extend the working temperature and the life of a gas turbine by providing a layer of thermal insulation between the metallic substrate and the hot gas. Yttria （Y203）, as one of the most important rare earth oxides, has already been used in the typical TBC material YSZ （yttria stabilized zirconia）. In the development of the TBC materials, especially in the latest ten years, rare earths have been found to be more and more important. All the new candidates of TBC materials contain a large quantity of rare earths, such as R2Zr207 （R=La, Ce, Nd, Gd）, CeO2-YSZ, RMeAI11019 （R=La, Nd; Me=Mg, Ca, Sr） and LAP04. The concept of double-ceramic- layer coatings based on the rare earth materials and YSZ is effective for the improvement of the thermal shock life of TBCs at high temperature.

关键词： Rare earth Thermal barrier coatings Gas turbine

(Yb_(0.25)Lu_(0.25)Er_(0.25)Y_(0.25))_(2)Si_(2)O_(7)高熵硅酸盐热环境障涂层的性能研究

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中国稀土学报 2024年第4期42卷 752-761,I0004页

作者：王泽通董淑娟毛传勇蒋佳宁邓龙辉曹学强武汉理工大学硅酸盐建筑材料国家重点实验室湖北武汉430070

通过高熵化设计制备了一种新型焦硅酸盐涂层材料(Yb_(0.25)Lu_(0.25)Er_(0.25)Y_(0.25))_(2)Si_(2)O_(7),采用大气等离子喷涂(APS)在碳化硅纤维增强碳化硅陶瓷复合材料(SiC_(f)/SiC-CMCs)表面制备了(4RE_(0.25))_(2)Si_(2)O_(7)一体化热环境障涂层(TEBCs)体系和LaMgAl_(11)O_(19)/Lu_(2)Si_(2)O_(7)热/环境障涂层(T/EBCs)体系。通过研究两种涂层体系的微观结构、热物理性能、水氧腐蚀性能以及热循环寿命等结果发现:APS制备的(4RE_(0.25))_(2)Si_(2)O_(7)涂层从室温到1500℃为稳定的β相,(4RE_(0.25))_(2)Si_(2)O_(7)涂层不存在成分偏析,热导率和热膨胀系数相对Lu_(2)Si_(2)O_(7)涂层有所降低,更适合作为一体化TEBCs使用;(4RE_(0.25))_(2)Si_(2)O_(7)TEBCs体系的水氧腐蚀寿命高于80 h,LaMgAl_(11)O_(19)/Lu_(2)Si_(2)O_(7)T/EBCs体系的水氧腐蚀寿命低于80 h;(4RE_(0.25))_(2)Si_(2)O_(7)TEBCs体系的热循环寿命为168次;高熵化设计使焦硅酸盐涂层CTE适配度提高,断裂韧性增强,进而增加了TEBCs体系的热循环寿命。

关键词：高熵化设计热环境障涂层(TEBCs) 相稳定性高温水氧腐蚀热循环焦硅酸盐稀土

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碳化硅复合材料的水氧腐蚀机理

硅酸盐学报 2024年第6期52卷 1978-1986页

作者：曾雨琪李归宋阁罗潇黄晶琪陈文博李坚徐友良曹学强中国航发湖南动力机械研究所湖南株洲412000 武汉理工大学硅酸盐建筑材料国家重点实验室武汉430070

为阐明碳化硅复合材料(SiC_(f)/SiC)航空发动机燃气环境中被H_(2)O和O_(2)的腐蚀机理,本工作研究了SiC_(f)/SiC复合材料在水热(无氧)和水氧耦合环境的腐蚀行为。结果表明,SiC_(f)/SiC复合材料连通孔隙是腐蚀介质/产物的进出通道;在200... 详细信息

为阐明碳化硅复合材料(SiC_(f)/SiC)航空发动机燃气环境中被H_(2)O和O_(2)的腐蚀机理,本工作研究了SiC_(f)/SiC复合材料在水热(无氧)和水氧耦合环境的腐蚀行为。结果表明,SiC_(f)/SiC复合材料连通孔隙是腐蚀介质/产物的进出通道;在200℃无氧水热环境中,Si C被水腐蚀是一个体积膨胀过程,形成乳白色产物H_(2)Si O_(3);在1300℃水氧耦合腐蚀环境中,SiC_(f)/SiC复合材料的纤维与界面层被腐蚀,结构变疏松,腐蚀中间产物为H_(2)SiO_(3),最终产物为方石英SiO_(2)。

关键词：碳化硅复合材料水氧腐蚀

碳化硅陶瓷基复合材料表面环境障涂层结合强度

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材料工程 2024年第2期52卷 198-206页

作者：苏超群邓龙辉刘若愚蒋佳宁云海涛李归苗小锋陈文博易出山刘俐董淑娟曹学强中国航发南方工业有限公司湖南株洲412002 武汉理工大学硅酸盐建筑材料国家重点实验室武汉430070

SiC陶瓷基复合材料(SiC-based ceramic matrix composites,SiC-CMC)是发展高推重比航空发动机理想的高温结构材料。为了防止发动机服役环境下燃气(富含H2O和O_(2))对SiC-CMC的腐蚀,需要在其表面制备抗水氧腐蚀、抗燃气冲刷和抗热冲击性... 详细信息

SiC陶瓷基复合材料(SiC-based ceramic matrix composites,SiC-CMC)是发展高推重比航空发动机理想的高温结构材料。为了防止发动机服役环境下燃气(富含H2O和O_(2))对SiC-CMC的腐蚀,需要在其表面制备抗水氧腐蚀、抗燃气冲刷和抗热冲击性能优异的环境障涂层(environmental barrier coatings,EBCs)。在评价EBCs性能的诸多因素中,其与SiC-CMC基体之间的结合强度是一个重要技术指标,但结合强度的极限值一直未被探究清楚。本工作研究影响结合强度的主要因素,包含SiC-CMC基体状态、单晶Si的拉伸强度极限,以及Si黏结层的制备工艺等,获得了制备最高结合强度的有效途径。在EBCs与SiC-CMC组成的体系中,基体内部SiC纤维布之间的界面是结合强度最薄弱的部位,其次是EBCs的Si层。整个体系的结合强度极限值是15 MPa,它是单晶Si在[400]晶向的拉伸强度极限。采用大气等离子喷涂或者超音速火焰喷涂的Si黏结层结合强度相似,均低于同样工艺制备的莫来石或Yb2Si2O7涂层。

关键词：碳化硅复合材料环境障涂层结合强度

Nanocrystalline La2Mo2O9 and Its Characterization

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Journal of Rare Earths 2004年第Z2期22卷 102-106页

作者： Li Qin Xia Tian Li Jiayan Liu Xiangdong Ma Xianfeng Meng Jian cao xueqiang Key Laboratory of Rare Earth Chemistry and Physics Changchun Institute of Applied ChemistryChinese Academy of Sciences.Changchun 130022China Key Laboratory of Rare Earth Chemistry and PhysicsChangchun Institute of Applied ChemistryChinese Academy of Sciences.Changchun 130022China Key Laboratory of Rare Earth Chemistry and PhysicsChangchun Institute of Applied ChemistryChinese Academy of Sciences.Changchun 130022China Key Laboratory of Rare Earth Chemistry and PhysicsChangchun Institute of Applied ChemistryChinese Academy of Sciences.Changchun 130022China Key Laboratory of Rare Earth Chemistry and PhysicsChangchun Institute of Applied ChemistryChinese Academy of Sciences.Changchun 130022China Key Laboratory of Rare Earth Chemistry and PhysicsChangchun Institute of Applied ChemistryChinese Academy of Sciences.Changchun 130022China Key Laboratory of Rare Earth Chemistry and PhysicsChangchun Institute of Applied ChemistryChinese Academy of Sciences.Changchun 130022China

In this work, both the thermal expansion and electrical conductivity of nanocrystalline La2Mo2O9 were *** nanocrystalline powder of La2Mo2O9 was obtained by sol-gel method, and with the help of SHP (superhigh pressure)up to 4.5 × 104 atm at 700 ℃ for a short time, and the nanocrystalline powder was densified without obvious particle size growth. The electrical conductivity of nanocrystalline La2Mo2O9 was one orderof magnitude lower than that of the microcrystalline sample at the same temperature. Owing to the phase transition, the microcrystalline La2Mo2O9 has an abrupt increase of thermal expansion with a peak value of 48 × 10-6 K-1 at 556 ℃. For the nanocrystalline material, the peak value increases to 112 × 10-6 K-1 at 520 ℃. On the other hand, above 600 ℃ the significant growth of particle size of the nanocrystalline La2Mo2O9 was observed, accompanying by a tremendous increase of thermal expansion with a peak value of third higher than that of La2Mo2O9.

关键词： nanocrystalline electrical conductivity lanthanum molybdate superhigh pressure rare earths

Quantitative analysis modeling for the Chem Cam spectral data based on laser-induced breakdown spectroscopy using convolutional neural network

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Plasma Science and Technology 2020年第11期22卷 81-90页

作者： xueqiang cao Li ZHANG Zhongchen WU Zongcheng LING Jialun LI Kaichen GUO School of Mechanical Electrical&Information EngineeringShandong UniversityWeihai 264209People's Republic of China Shandong Provincial Key Laboratory of Optical Astronomy and Solar-Terrestrial Environment Institute of Space SciencesShandong UniversityWeihai 264209People's Republic of China

Laser-induced breakdown spectroscopy(LIBS)has been applied to many fields for the quantitative analysis of diverse *** the prediction accuracy of LIBS regression models is still of great significance for the Mars exploration in the near *** this study,we explored the quantitative analysis of LIBS for the one-dimensional Chem Cam(an instrument containing a LIBS spectrometer and a Remote Micro-Imager)spectral data whose spectra are produced by the Chem Cam team using LIBS under the Mars-like atmospheric *** constructed a convolutional neural network(CNN)regression model with unified parameters for all oxides,which is efficient and *** that has the excellent capability of feature extraction can effectively overcome the chemical matrix effects that impede the prediction accuracy of regression ***,we explored the effects of four activation functions on the performance of the CNN *** results show that the CNN model with the hyperbolic tangent(tanh)function outperforms the CNN models with the other activation functions(the rectified linear unit function,the linear function and the Sigmoid function).Secondly,we compared the performance among the CNN models using different optimization *** CNN model with the stochastic gradient descent optimization and the initial learning rate?=?0.0005 achieves satisfactory performance compared to the other CNN ***,we compared the performance of the CNN model,the model based on support vector regression(SVR)and the model based on partial least square regression(PLSR).The results exhibit the CNN model is superior to the SVR model and the PLSR model for all *** on the above analysis,we conclude the CNN regression model can effectively improve the prediction accuracy of LIBS.

关键词： laser-induced breakdown spectroscopy convolutional neural network activation function optimization method quantitative analysis

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新型热障涂层材料研究进展(英文)

硅酸盐学报 2020年第10期48卷 1622-1635页

作者：曹学强武汉理工大学硅酸盐建筑材料国家重点实验室武汉430070

热障涂层是高温下具有良好隔热性能的陶瓷涂层,在燃气轮机、内燃机、火箭发动机和其他高温热防护方面有重要应用。稀土或碱土金属氧化物稳定的氧化锆热障涂层材料已应用近60 a,其中最常用的是氧化钇稳定的氧化锆(YSZ)。近20 a,国内外发... 详细信息

热障涂层是高温下具有良好隔热性能的陶瓷涂层,在燃气轮机、内燃机、火箭发动机和其他高温热防护方面有重要应用。稀土或碱土金属氧化物稳定的氧化锆热障涂层材料已应用近60 a,其中最常用的是氧化钇稳定的氧化锆(YSZ)。近20 a,国内外发现了许多新材料,如稀土锆酸盐、铝酸盐和钽酸盐等。与YSZ相比,新材料在高温稳定性、热导率、抗烧结或热膨胀性能方面有优势,但断裂韧性低、成分复杂、单一陶瓷层的热循环寿命短。为了提高新型热障涂层的寿命,要严格控制涂层的制备过程、保持化学计量比,采用双陶瓷层结构的涂层。

关键词：热障涂层稀土氧化锆锆酸盐铝酸盐