高超声速飞行器陶瓷复合材料与热结构技术研究进展

高超声速飞行器热防护材料与结构是关系高超声速飞行器安全的关键热防护技术.陶瓷复合材料具有耐高温和稳定性好等优点,成为高超声速飞行器高温区和大面积区域所用的最重要的热防护结构材料.回顾了陶瓷复合材料在高超声速飞行器热防护系统中的应用,从材料制备、抗氧化以及物理性能等方面综述了美国陶瓷隔热材料和陶瓷防热材料技术研究进展与应用现状,详细介绍了陶瓷材料与结构的最新研究进展,特别是新型的防热-隔热一体化陶瓷瓦,总结了陶瓷瓦所采用的热防护技术的改进升级,指出了高超声速飞行器陶瓷材料与结构面临的挑战,最后展望了应用于高超声速飞行器中的陶瓷复合材料与结构的未来发展方向.     

二氧化硅体系透波材料的透波机理及研究现状

本文阐述了天线罩材料对二氧化硅体系透波材料的性能要求,分析了二氧化硅体系透波材料的透波机理,论述了二氧化硅体系透波材料的研究现状,并指出了其发展方向.     

航天飞机及高超飞行器用刚性隔热材料研究进展

航天飞机及高超飞行器热防护材料是关系航天飞机及高超飞行器安全的关键之一。刚性高效隔热材料具有耐高温和稳定性好等优点，成为航天飞机和高超声速飞行器高温区和大面积区域所用的重要的热防护结构材料。本文回顾了刚性高效隔热材料在高超声速飞行器热防护系统中的应用，综述美国刚性隔热材料技术研究进展与应用现状，介绍了刚性隔热材料在美国航天飞机及飞行器中的应用，特别是新型的防热-隔热一体化陶瓷瓦的应用。此外，概括了国内刚性隔热材料的研究情况，最后展望了应用于高超声速飞行器中的隔热材料未来发展。     

FRP透波窗性能设计研究

本研究针对FRP透波窗在使用频段范围实现透波率和结构性能的需求，通过材料选择、透波性能设计、仿真分析和结构设计，采用夹层结构形式，制造了FRP透波窗试验件，进行了结构试验和透波试验。试验结果表明，FRP透波窗的结构设计满足承载和密封性要求，同时在1.0GHz～3.0GHz频段范围内的透波率均大于80%,满足透波性要求。实现了对FRP透波窗的承载、密封和透波的设计要求，可以对内部设备的运行状态实现监测。     

透波复合材料的研究进展

介绍了我国通用透波复合材料、特种透波复合材料、隐身透波复合材料的性能水平,概括地总结了我国雷达罩用功能透波复合材料的研究进展,并对今后的发展方向进行了预测。     

纤维增强树脂基复合材料透波板的研制和试验

本文介绍了一种新型的天线窗用纤维增强树脂基复合材料透波板的研制过程,并对研制的透波板在透波率、抗高低温能力、抗震动冲击能力和承载能力等几方面进行了试验验证。结果表明,新研制的透波板具有良好的透波性能和力学性能。     

微波加热用透波材料的研究进展

微波加热技术因其绿色环保、体积加热、选择性加热等优势,已被广泛应用于化工强化、金属冶炼、陶瓷烧结、食品加工等众多领域,但微波在反应器内普遍存在透波效果差、微波利用率低等问题。随着微波加热技术的不断发展,微波加热设备中透波材料的选用越来越受到大家的关注。本文主要针对透波材料在微波加热领域中的应用现状进行综述,对透波材料的种类进行简要介绍,分别从微波加热用容器和保温材料两方面进行论述。详细介绍了氧化物、氮化物、硅酸盐、磷酸盐等高温透波材料及聚四氟乙烯、玻纤增强树脂基、环氧树脂等中、低温透波材料的研究进展,并具体论述了目前微波加热常用纤维棉、纤维毯和纤维板等各种陶瓷纤维制品的介电特性和透波性能,最后指出了目前微波加热用透波材料普遍存在的问题,并对透波材料的应用和发展作出了展望。     

氮化硅陶瓷在四大领域的研究及应用进展

氮化硅陶瓷不仅具有较高的力学性能还具有良好的透波性能、导热性能以及生物相容性能,是公认的综合性能最优的陶瓷材料。作为轴承球的致密氮化硅陶瓷广泛应用在机械领域;作为透波材料的多孔氮化硅陶瓷广泛应用在航空航天领域;随着对氮化硅陶瓷材料的深入研究,其在导热性和生物相容性方面的优异特性逐渐被科研工作者认识并得到开发和应用。本文详细阐述了氮化硅粉体的制备方法,并综述了氮化硅陶瓷作为结构陶瓷在机械领域和航空航天领域的研究进展,此外还介绍了其作为功能陶瓷在半导体领域、生物制药领域的研究和应用现状,最后对其未来发展进行了展望。     

透波复合材料研究进展

介绍透波材料的选用原则及其介电特性，探讨了树脂基、无机非金属基通用透波复合材料和人工介质材料、耐高温有机材料等特种透波复合材料的研究进展，简介湿度、树脂含量、孔隙率、吸水性、后处理温度及时间、纤维表面处理等因素对复合材料常温透波性能的影响及结构／微结构、成分／微成分、物态相变等材料的本征因素对复合材料高温透波性能的影响。     

透波材料在微波冶金领域的应用进展

综述了透波材料的研究现状,探讨了目前在不同的微波冶金温度区间所需的微波透波材料。聚四氟乙烯等可作为低温微波透波材料,xMeO.yAl2O3.zSiO2陶瓷体系已经作为高温微波冶金透波材料,继续研究适合微波加热不同温段的透波材料体系是目前微波冶金发展的迫切需要。     

High-enthalpy test environments,flow modeling and in situ diagnostics for characterizing ultra-high temperature ceramics

Ultra-high temperature ceramic materials and composites under development as nose-tip and wing leading edge components for hypersonic flight vehicles must operate in extreme aerothermal heating environments. The performance of ultra-high temperature ceramics for this application is ultimately evaluated using high-enthalpy, long duration flow facilities that simulate the reactive gas environment encountered in hypersonic flight. In this paper, we describe the test environments generated by two types of these ground test facilities – subsonic inductively coupled plasma tunnels and supersonic arc-jet tunnels – and discuss the important roles of computational fluid dynamics modeling and in situ optical diagnostics for interpreting test results from a materials science perspective.     

高超音速导弹天线罩透波材料研究进展

高超音速导弹用天线罩材料须同时具有力学、介电、耐烧蚀及抗冲击等综合性能.本文简述了天线罩材料的发展历程,着重综述了连续纤维增强陶瓷基透波复合材料的研究现状,分析了高超音速导弹天线罩材料的关键技术,包括材料体系和制备工艺选择、材料加工技术,指出了高超音速导弹天线罩材料的发展方向.     

Experimental and computational analysis of thermo‐oxidative‐structural stability of ZrB2–SiC–Ti during arc‐jet testing

The development of new ultra‐high temperature ceramics for thermal protection system (TPS) of hypersonic cruise and re‐entry vehicles requires performance‐qualification testing under simulated flight conditions. The present work, encompassing experiments and computational analysis, critically analyzes the thermo‐oxidative‐structural stability of flat surface disks of spark plasma sintered ZrB₂–18SiC–xTi composites (x=0, 10, 20; composition in wt%) under arc jet flow with heat flux of 2.5 MW/m² for 30 seconds. Such testing conditions effectively simulate the aero‐thermal environment in ground facility, as experienced by hypersonic vehicles. Based on the extensive XRD, SEM‐EDS and electron probe microanalyzer based analysis of the surface/sub‐surface of arc jet exposed ceramics, the oxidation mechanisms are qualitatively discussed. Importantly, thick oxide layers (~400‐950 μm) were found to be adherent, thereby providing good structural stability of such ceramics for reusable TPS. The careful finite element (FE) analysis with high quality structural elements, being generated using HyperMesh, was conducted to understand the underlying reasons for observed oxidation. Such analysis allows us to determine the temporal evolution of through‐thickness temperature distribution. FE‐based calculations were subsequently validated using experimentally measured backwall temperatures. The thermodynamic feasibility of competing oxidation reactions at the analytically computed front wall temperatures was thereafter realistically assessed to support the oxidation mechanisms. Taken together, the present work provides guidelines for better understanding of the thermo‐oxidative‐structural stability of ceramics under arc jet testing and also establishes the good stability of ZrB₂–18SiC–20Ti composites for potential application in TPS of hypersonic space vehicles.     

陶瓷刀具材料的现状与发展

本文阐述了陶瓷刀具材料的发展现状 ,着重论述了氧化铝系陶瓷和氮化硅系陶瓷材料技术。对陶瓷刀具材料的发展趋势进行了综述。指出超微粉刀具、复相陶瓷刀具、涂层刀具及金属陶瓷是陶瓷刀具材料的研究方向。     

The two-tier tissue reinforcing and toughening mechanism caused by dual-granularity Si powders ingredient,and dielectric properties in reaction bonded and sintered reaction bonded Si3N4 porous ceramics

With the rapid development of hypersonic vehicles and broadband wave-transparent radome, Si₃N₄ porous ceramics (Si₃N₄-PC) have attracted attention due to their excellent intrinsic properties of Si₃N₄ and high porosity. However, its high porosity results in low strength and toughness, which are fundamental properties for radome. Reaction bonded (RB) Si₃N₄-PC has advantages of dielectric properties and cost over general phase transformation sintering (PTS) and sintered reaction bonded (SRB) Si₃N₄-PC while it has been neglected in recent years. In this study, RB and SRB Si₃N₄-PC prepared by non-aqueous gelcasting and the influence of Si powders ingredient on their properties are discussed in order to illuminate the potential of RB Si₃N₄-PC in wave-transparent materials. The results show that RB Si₃N₄-PC with dual-granularity ingredients of 5 μm & 45 μm produces a two-tier tissue of framework of coarse whiskers enhanced by a network of tiny whiskers. SRB Si₃N₄-PC evolves into a two-tier tissue of framework of columnar and rod-like grains joining together to brace each other. The two-tier microscopic tissue strongly reinforces and toughens the structure and results in higher σ_F and γ_wof. As a result, the RB and SRB Si₃N₄-PC of dual-granularity of 5 μm & 45 μm obtain the maximum σ_F of 109.94 MPa and 119.56 MPa as well as maximum γ_wof of 990.74 J m^-2 and 1167.88 J m^-2, respectively. Furthermore, the ε′ and tanδ of RB and SRB Si₃N₄-PC of dual-granularity of 5 μm & 45 μm are about 4.20 and 4.52 as well as 7.01 × 10^-3 and 22.90 × 10^-3, respectively. It is concluded that RB Si₃N₄-PC of dual-granularity has good mechanical and dielectric properties, which are favorable for radome.     

Evaluation and design methods for high-efficiency charring composite under complex coupling mechanisms in both material and boundary layer

With the development of hypersonic vehicles, reentry vehicles are facing a more severe aerothermodynamic heating environment. It is necessary to design high-efficiency charring composite used as the heat shield in the thermal protection system (TPS) of reentry vehicles. By taking the material responses (volume-surface coupled ablation), exothermic gas-phase reactions of pyrolysis gases in the boundary layer and the flow behavior of chemical nonequilibrium inflow coupling ablative mechanism into consideration, a developed thermal/fluid/chemical/ablation coupling model with the key influencing factor on thermal protection performance of charring composites is built to evaluate the material responses and the chemical responses in boundary layer near its surface. Based on this model, the key factor (fiber volume fraction) influencing on the thermal protection performance is analyzed by using a coupling numerical calculation strategy. By designing the distribution of this parameter along the thickness of the material, a gradient design for charring composite is given. The numerical results indicate that the gradient charring composite can control the temperature distribution and the amount of surface ablation recession. This study will be a guidance for the design of charring composites for thermal protection application in reentry vehicles in a quantitative and efficient manner.     

Progress and perspectives on composite laser ceramics: A review

Solid-state laser has been widely used in industrial production, military weapons and scientific research because of its compact structure, convenient use and high output power. As the core material of solid-state laser, gain media are the key to its further development. Therefore, the design of appropriate composite structure gain media has attracted extensive attention. Especially for laser ceramics with excellent structural designability, the research on their composite structures has developed rapidly, such as surface gain structure that can improve thermal conductivity; concentration gradient doping structure that can improve energy storage capacity and temperature gradient; clad-core structure which can suppress ASE effect and optical waveguide structure which can improve thermal effect and facilitate device miniaturization. In this paper, the structure design, materials preparation and performance advantages of different composite laser ceramics have been introduced systematically. Finally, the progress of composite laser ceramics is summarized, and the prospect is put forward.     

产品设计在陶瓷材料中的应用

从产品设计者的角度出发,以新产品的开发和创造为目的,充分发掘陶瓷材料的特性和潜能,从构成陶瓷产品的功能、形态、情感等因素入手,阐述了产品设计在工艺美术陶瓷、日用陶瓷以及功能陶瓷及其复合材料中的应用。在此基础上探讨了陶瓷产品设计是以陶瓷材料为主体,以形成功能效用和形式美感与物质技术融为一体为目的的系统设计,是科学技术和文化艺术相结合的产物,是一个创造性的构思、行为和实现的过程,在这一过程中产品设计和陶瓷材料在相互促进中共同发展。     

Dielectric and mechanical properties of hypersonic radome materials and metamaterial design: A review

This review paper examines ten current ceramic radome materials under research and development and provides a comprehensive overview of available high temperature and high frequency data from literature. An examination of metamaterials for radio-frequency transparent radomes is given and our preliminary experimental results of a high-temperature metamaterial design are presented. The next-generation hypersonic vehicles’ radome temperatures will exceed 1000℃ and speeds will exceed Mach 5. An ideal radome material will have a high flexural strength, low dielectric constant and loss tangent, and high resistance to thermal shock and corrosion. The microstructural effect on the dielectric and mechanical properties and the effects of environmental factors such as rain are discussed. The impact of metamaterial structure on key radome factors such as boresight error, gain, and polarization is examined. After examining the associated benefits with the use of metamaterials, our preliminary results for a potential high-temperature metamaterial design are presented.     

可加工陶瓷材料研究进展

介绍了国内外可加工陶瓷材料的研究现状,包括可加工玻璃陶瓷、可加工Ti_3SiC_2陶瓷、可加工SiC、Si_3N_4陶瓷、可加工复相陶瓷以及可加工陶瓷的各种加工技术,并对其发展趋势进行了展望。