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Facile preparation of a SiC@SiO_(2)nanowire-toughened ZrB_(2)-SiC/SiC bilayer coating with good interfacial bonding,high toughness,and excellent cyclic ablation resistance on C/CA composites

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Journal of Advanced Ceramics 2024年第4期13卷 486-495页

作者： Meng Yan Chenglong Hu Jian Li Shengyang Pang Bohui Sun Rida Zhao Bin Liang Rui Luo sufang tang Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China

Preparing antioxidant coatings to address the inherent oxidation sensitivity of carbon fiber-reinforced carbon aerogel(C/CA)composites is a feasible way to promote their application in oxidizing environments as thermal insulation ***,preparing the coatings with excellent oxidation and ablation resistance while avoiding evident damage to the C/CA substrate still remains a ***,a SiC@SiO_(2)nanowire-toughened ZrB2–SiC/SiC bilayer coating with a large thickness of 500μm was prepared on C/CA using a one-step low-temperature reaction sintering method,which simultaneously formed a sintered outer layer with even-distributed nanowires and a siliconized gradient inner *** courtesy of the synergic thermal response of the layers and the crack deflection induced by the nanowires,the resulting coating has moderate residual compressive stress of 0.08–1.22 GPa in the interface,high interfacial bonding strength of 6.02 MPa,and good fracture toughness of 4.36 MPa·m^(1/2).Benefited from the optimum components and improved structure,the coating shows excellent cyclic ablation resistance with linear ablation rates of 0.1μm/s at 1650℃for 1500 s(300 s×5 cycles)and 0.4μm/s at 1850℃for 900 s(300 s×3 cycles).The one-step preparation strategy contributes to little damage to the substrate,thus showing the well-preserved mechanical and thermal insulation properties.

关键词： coating carbon fiber reinforced carbon aerogel(C/CA)composites toughness interface residual stress

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多孔碳陶瓷化改进反应熔渗法制备陶瓷基复合材料研究进展

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无机材料学报 2024年第6期39卷 623-633页

作者：赵日达汤素芳中国科学院金属研究所前沿材料研究部沈阳110016

连续纤维增强陶瓷基复合材料具有高强韧、耐氧化的特性,现已成为航空航天领域重要的高温结构候选材料。反应熔渗法可实现陶瓷基复合材料的大规模、短周期和低成本制备,是目前最具有商业化前景的技术之一。然而,传统反应熔渗法制得陶瓷... 详细信息

连续纤维增强陶瓷基复合材料具有高强韧、耐氧化的特性,现已成为航空航天领域重要的高温结构候选材料。反应熔渗法可实现陶瓷基复合材料的大规模、短周期和低成本制备,是目前最具有商业化前景的技术之一。然而,传统反应熔渗法制得陶瓷基复合材料存在着基体碳残留、纤维刻蚀等问题,导致材料力学与氧化-烧蚀性能不佳。为突破传统碳基体陶瓷化程度低的局限性,相关研究人员采用碳基体孔结构构筑方法,通过多孔碳基体取代传统熔渗预制体中致密碳基体,以促进碳基体的陶瓷化转变及反应熔体的消耗,进而实现陶瓷基复合材料的性能优化。本综述介绍了采用多孔碳陶瓷化策略制备SiC陶瓷、SiC/SiC复合材料、C/SiC复合材料及超高温陶瓷基复合材料的相关研究进展,并且通过与传统反应熔渗法对比,验证了多孔碳陶瓷化策略的优势,同时总结了相关多孔碳基体制备方法的发展演变过程,最后针对先进陶瓷基复合材料的基础理论与工艺技术需求,对多孔碳陶瓷化改进反应熔渗法的未来发展方向进行了展望。

关键词：陶瓷基复合材料反应熔渗法多孔碳陶瓷化综述

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C/SiC-BN复合材料的制备及氧化行为

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无机材料学报 2024年第7期39卷 779-786页

作者：姜灵毅庞生洋杨超张悦胡成龙汤素芳沈阳工业大学材料科学与工程学院沈阳110870 中国科学院金属研究所沈阳110016

C/SiC复合材料作为一种高温结构材料,在航空航天热防护领域具有广泛的应用前景。然而,该材料的中低温抗氧化性能相对较差,制约了其在更广泛领域的应用。本研究采用料浆抽滤工艺,通过调节料浆中陶瓷含量在纤维增强体中引入不同含量的抗... 详细信息

C/SiC复合材料作为一种高温结构材料,在航空航天热防护领域具有广泛的应用前景。然而,该材料的中低温抗氧化性能相对较差,制约了其在更广泛领域的应用。本研究采用料浆抽滤工艺,通过调节料浆中陶瓷含量在纤维增强体中引入不同含量的抗氧化组元BN,再通过反应熔体渗透法制备C/SiC-BN复合材料。系统研究了不同BN含量对复合材料结构组成及抗氧化行为的影响,并分析相关氧化机理。研究结果表明:引入BN颗粒显著降低了C/SiC的开口孔隙率,并明显提高了C/SiC的起始氧化温度。引入质量分数3%BN时,C/SiC-BN复合材料(B3样品)的抗氧化性能最优,其在900、1200和1500℃静态氧化1 h的质量损失率分别为0.009%、–0.301%、–0.596%,显著优于C/SiC。1500℃氧化后,B3样品的强度保持率最高,达到52%。900℃氧化时,C/SiC-BN复合材料主要经历C相和BN相的氧化,以O_(2)扩散反应控制的缓慢失重为主;1200℃氧化时,C相和BN相氧化速率加快,SiC发显著氧化,生成的B_(2)O_(3)、硼硅酸盐和SiO_(2)等氧化产物减缓了O_(2)的扩散速率,减小了基体碳的损伤;1500℃氧化时,SiC氧化速率加快,生成的SiO_(2)在复合材料表面形成的连续氧化膜阻碍了O_(2)的向内扩散。B_(2)O_(3)、CO等气体产物溢出及持续生成SiO_(2)主导了整个氧化过程。

关键词：料浆浸渍 C/SiC BN 微观结构氧化行为

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Capillary infiltration of liquid silicon in carbon nanotubes:A molecular dynamics simulation

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Journal of Materials Science & Technology 2023年第13期144卷 219-223页

作者： Kangyu Zhang Rida Zhao Yongqiang Yang Lichang Yin sufang tang Shenyang National Laboratory for Materials Science Institute of Metal ResearchChinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang 110016China Department of Physics and Electronic Information Huaibei Normal UniversityAnhuiHuaibei 235000China

In this work,by simplifying the nanopores of porous C/C preform with single-walled carbon nanotubes(SWCNT)or double-walled carbon nanotubes(DWCNTs),the infiltration of liquid Si in the SWCNTs and DWCNTs was studied by molecular dynamics(MD)*** a result,a quantitative relationship between tube diameter and liquid Si infiltration rate was established,which has been successfully ap-plied to reproduce the available experiment *** obtained relationship indicates that the capillary infiltration of liquid Si at the nanoscale still conforms to the classic Lucas-Washburn law,however,the liquid Si infiltration quickly stops in small tubes with a diameter of less than 3 nm due to an obvious contraction of the tube *** work may provide theoretical guidance for pore structure optimization of porous C/C preform to fabricate high-density C/SiC composites.

关键词： Silicon carbide Molecular dynamics Capillary infiltration,Liquid silicon,Carbon nanotube

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Mechanical Properties and Oxidation Behaviors of Self-Healing SiCf/SiC-SiBCN Composites Exposed to H_(2)O/O_(2)/Na_(2)SO_(4)Environments

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Acta Metallurgica Sinica(English Letters) 2023年第11期36卷 1909-1923页

作者： Suya Ji Bin Liang Chenglong Hu Shengyang Pang Rida Zhao Jian Li sufang tang Shi-Changxu Innovation Center for Advanced Materials Institute of Metal ResearchChinese Academy of SciencesShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaShenyang110016China

The oxidation behaviors and their influence on the mechanical properties of self-healing SiCf/SiC-SiBCN composites were investigated in H_(2)O/O_(2)and H_(2)O/O_(2)/Na_(2)SO_(4)environments at 1200‒1350℃for 100 *** the temperatures increase from 1200 to 1350℃,the oxidation rate constants increase from 0.45×10^(–7)to 1.58×10^(–7)mg^(2)/(mm^(4) h)in H_(2)O/O_(2),and from 1.02×10^(–7)to 3.42×10^(–7)mg^(2)/(mm^(4) h)in H_(2)O/O_(2)/Na_(2)SO_(4).The involvement of Na_(2)SO_(4)leads to the formation of a loose lamellar oxide layer,the breakage of the SiBCN/CVI-SiC interface and the decrease in the oxide viscosity,thus accelerating the oxidation of the *** composites show the maximum retention rate of strength(102%,535.71 MPa)after oxidation in H_(2)O/O_(2)at 1200℃due to the good self-healing capacity of the produced glass,while the minimum(82%,430.56 MPa)in H_(2)O/O_(2)/Na_(2)SO_(4)at 1350℃caused by the severe microstructural corrosion derived from Na_(2)SO_(4).

关键词： SiCf/SiC-SiBCN composite Mechanical property Oxidation Chemical vapor infiltration and polymer infiltration and pyrolysis(CVI-PIP) Self-healing

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Deposition kinetics and mechanism of pyrocarbon for electromagnetic-coupling chemical vapor infiltration process

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Journal of Materials Science & Technology 2022年第6期101卷 118-127页

作者： Chenglong Hu Rida Zhao Sajjad Ali Yuanhong Wang Shengyang Pang Jian Li sufang tang Institute of Metal Research Chinese Academy of SciencesShenyang 110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei 230026China Department of Physics Southern University of Science and TechnologyShenzhen 518055China The 31st Research Institute of China Aerospace Science and Industry Corp Beijing 100074China

Although the electromagnetic-coupling chemical vapor infiltration(E-CVI)has been proven of a highefficiency technique for producing carbon fiber reinforced pyrocarbon(Py C)matrix(C/C)composites,a deep understanding of the deposition kinetics and mechanism of Py C matrix is still *** this work,a deposition model with uniform electric field but gradient magnetic field was set up by using unidirectional carbon fiber bundles as the substrates to investigate the deposition kinetics and ***,the polarizability,and the chemical adsorption and dehydrogenation barriers of hydrocarbon were simulated based on the density functional theory(DFT)and the Climb-image nudged elastic band method,*** E-CVI process exhibited extremely high Py C deposition rates of 8.7,11.5,16.5 and 22.7 nm/s at 700,750,800 and 850℃,respectively,together with a significantly low apparent activation energy of 57.9 k J/mol within the first 5 *** Py C deposited at different temperatures with different time shows a smooth laminar structure with low coherent length and graphitization *** theoretical calculation and simulation results indicated that the electrons existing on the carbon fibers and the accelerated motion of radicals with preferred orientation forced by the derived magnetic field have reduced the energy barrier for the deposition process,thereby resulting in low apparent activation energy and high Py C deposition *** results of this work may shed a light on how to better direct the preparation of C/C composites by E-CVI process with high quality and efficiency.

关键词： Electromagnetic-coupling chemical vapor infiltration CVI C/C composites Deposition mechanism

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注射用头孢他啶的质量分析

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中国抗生素杂志 2024年第3期49卷 273-282页

作者：杜旭刘海玲郭艳娟张琳王悦雯鲁瑞娟杨倩唐素芳天津市药品检验研究院天津300070

目的评价国内注射用头孢他啶的质量现状。方法采用调研、文献检索、法定标准检验结合探索性研究的方式,对国内36家企业生产的177批次的注射用头孢他啶和原研制剂的质量进行比较分析;通过对杂质谱、配伍稳定性、包材相容性等关键质量... 详细信息

目的评价国内注射用头孢他啶的质量现状。方法采用调研、文献检索、法定标准检验结合探索性研究的方式,对国内36家企业生产的177批次的注射用头孢他啶和原研制剂的质量进行比较分析;通过对杂质谱、配伍稳定性、包材相容性等关键质量属性进行考察,分析不同企业产品的质量差异。结果 177批次注射用头孢他啶按法定标准检验均符合规定;但质量标准仍然存在部分项目检验方法和限度不统一,药品说明书表述不一致等问题。探索性研究中,优化了有关物质分析方法,采用LC/MS对产品中杂质的可能结构进行了推断,对其来源进行了分析。配伍稳定性结果表明,部分企业药品说明书不合理,存在风险隐患。结论注射用头孢他啶总体质量较好,现行标准有待统一和提高。

关键词：注射用头孢他啶国家药品抽检质量分析

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Effect of C/SiC Volume Ratios on Mechanical and Oxidation Behaviors of C_(f)/C-SiC Composites Fabricated by Chemical Vapor Infiltration Technique

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Acta Metallurgica Sinica(English Letters) 2022年第5期35卷 801-811页

作者： Jinjin Yao Shengyang Pang Yuanhong Wang Chenglong Hu Rida Zhao Jian Li sufang tang Hui-Ming Cheng Institute of Metal Research Chinese Academy of SciencesShenyang110016China School of Materials Science and Engineering University of Science and Technology of ChinaHefei230026China The 31St Research Institute of China Aerospace Science and Industry Corp Beijing100074China Shenzhen Institute of Advanced Technology Chinese Academy of SciencesShenzhen518055China

C/SiC volume ratios in carbon fiber-reinforced carbon-silicon carbide(C_(f)/C-SiC)composites may influence greatly mechanical and oxidation properties of the composites,but have not been well investigated ***,C_(f)/C-SiC composites with different C/SiC volume ratios were fabricated by chemical vapor infiltration(CVI)technique through alternating the thickness of a pyrocarbon(PyC)*** composites with C/SiC volume ratios of 0.37 and 0.84 exhibited the better comprehensive mechanical *** CS0.37 showed the highest flexural strength of 340.6 MPa,and CS0.84 had the maximum tensile strength of 139.1 *** excellent mechanical properties were closely related to the relatively low C/SiC volume ratios and porosities,optimum interfacial bonding and reduced matrix *** composite with a low C/SiC volume ratio of 0.10 showed the best anti-oxidation performance due to its high SiC *** oxidation mechanisms at 1100℃and 1400℃were discussed by considering the effect of the C/SiC volume ratios,pores and matrix micro-cracks,oxidation of carbon phase and SiC.

关键词： C_(f)/C-SiC composites Chemical vapor infiltration Mechanical properties Oxidation properties

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Design, Preparation and Properties of Carbon Fiber Reinforced Ultra-High Temperature Ceramic Composites for Aerospace Applications： A Review

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Journal of Materials Science & Technology 2017年第2期33卷 117-130页

作者： sufang tang Chenglong Hu Institute of Metal Research Chinese Academy of Sciences Shenyang 110016 China

Carbon fiber reinforced ultra-high temperature ceramic （UHTC） composites, consisting of carbon fibers embedded in a UHTC-matrix or a C-SiC-UHTC-matrix, are deemed as the most viable class of materials that can overcome the poor fracture toughness and thermal shock resistance of monolithic UHTC ma- terials, and also improve the oxidation resistance and ablation resistance of C/C and C/SiC composites at ultra-high temperatures. In this review, we summarize the different processing routes of the compos- ites based on the UHTC introducing methods, including chemical vapor infiltration/deposition （CVI/D）, precursor infiltration and pyrolysis （PIP）, reactive melt infiltration （RMI）, slurry infiltration （SI）. in-sito reaction, hot pressing （HP）, etc; and the advantages and drawbacks of each method are briefly dis- cussed. The carbon fiber reinforced UHTC composites can be highly tailorable materials in terms of fiber. interface, and matrix. From the perspective of service environmental applications for engine propul- sions anti hypersonic vehicles, the material designs （mainly focusing on the composition, quantity, structure of matrix, as well as the architecture of carbon fibers, UHTCs and pores）, their relevant processing routes and properties （emphasizing on the mechanical and ablation properties） are discussed in this paper. In addition, we propose a material architecture to realize the multi-function through changing the distri- bution of carbon fibers, UHTCs and pores, which will be an important issue for future development of carbon fiber reinforced UHTC composites.

关键词： Carbon fiber composites Ceramic matrix composites (CMC) Ultra-high temperature ceramic (UHTC) Ablation

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Classification of positive solutions to an integral system with the poly-harmonic extension operator

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Science China Mathematics 2018年第9期61卷 1603-1616页

作者： sufang tang Jingbo Dou School of Statistics Xi'an University of Finance and Economics School of Mathematics and Information Science Shaanxi Normal University

In this paper, we investigate the positive solutions to the following integral system with a polyharmonic extension operator on R^+_n:{u(x)=c_n,a∫_?R_+~n(x_n^(1-a_v)(y)/|x-y|^(n-a))dy,x∈R_+~n,v(y)=c_n,a∫_R_+~n(x_n^(1-a_uθ)(x)/|x-y|^(n-a))dx,y∈ ?R_+~n,where n 2, 2-n 0. This integral system arises from the Euler-Lagrange equation corresponding to an integral inequality on the upper half space established by Chen(2014). The explicit formulations of positive solutions are obtained by the method of moving spheres for the critical case κ =n-2+a/n-a,θ =n+2-a/ n-2+a. Moreover,we also give the nonexistence of positive solutions in the subcritical case for the above system.

关键词：不可分系统 poly 操作符分类泛音操作员空格

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