Ultra High Temperature Ceramics for Hypersonic Vehicle Applications


Book Description

HfB{sub 2} and ZrB{sub 2} are of interest for thermal protection materials because of favorable thermal stability, mechanical properties, and oxidation resistance. We have made dense diboride ceramics with 2 to 20 % SiC by hot pressing at 2000 C and 5000 psi. High-resolution transmission electron microscopy (TEM) shows very thin grain boundary phases that suggest liquid phase sintering. Fracture toughness measurements give RT values of 4 to 6 MPam{sup 1/2}. Four-pt flexure strengths measured in air up to 1450 C were as high as 450-500 MPa. Thermal diffusivities were measured to 2000 C for ZrB{sub 2} and HfB{sub 2} ceramics with SiC contents from 2 to 20%. Thermal conductivities were calculated from thermal diffusivities and measured heat capacities. Thermal diffusivities were modeled using different two-phase composite models. These materials exhibit excellent high temperature properties and are attractive for further development for thermal protection systems.




Ultra-High Temperature Ceramics


Book Description

The first comprehensive book to focus on ultra-high temperature ceramic materials in more than 20 years Ultra-High Temperature Ceramics are a family of compounds that display an unusual combination of properties, including extremely high melting temperatures (>3000°C), high hardness, and good chemical stability and strength at high temperatures. Typical UHTC materials are the carbides, nitrides, and borides of transition metals, but the Group IV compounds (Ti, Zr, Hf) plus TaC are generally considered to be the main focus of research due to the superior melting temperatures and stable high-melting temperature oxide that forms in situ. Rather than focusing on the latest scientific results, Ultra-High Temperature Ceramics: Materials for Extreme Environment Applications broadly and critically combines the historical aspects and the state-of-the-art on the processing, densification, properties, and performance of boride and carbide ceramics. In reviewing the historic studies and recent progress in the field, Ultra-High Temperature Ceramics: Materials for Extreme Environment Applications provides: Original reviews of research conducted in the 1960s and 70s Content on electronic structure, synthesis, powder processing, densification, property measurement, and characterization of boride and carbide ceramics. Emphasis on materials for hypersonic aerospace applications such as wing leading edges and propulsion components for vehicles traveling faster than Mach 5 Information on materials used in the extreme environments associated with high speed cutting tools and nuclear power generation Contributions are based on presentations by leading research groups at the conference "Ultra-High Temperature Ceramics: Materials for Extreme Environment Applications II" held May 13-19, 2012 in Hernstein, Austria. Bringing together disparate researchers from academia, government, and industry in a singular forum, the meeting cultivated didactic discussions and efforts between bench researchers, designers and engineers in assaying results in a broader context and moving the technology forward toward near- and long-term use. This book is useful for furnace manufacturers, aerospace manufacturers that may be pursuing hypersonic technology, researchers studying any aspect of boride and carbide ceramics, and practitioners of high-temperature structural ceramics.




Boron Rich Solids


Book Description

The objective of this book is to discuss the current status of research and development of boron-rich solids as sensors, ultra-high temperature ceramics, thermoelectrics, and armor. Novel biological and chemical sensors made of stiff and light-weight boron-rich solids are very exciting and efficient for applications in medical diagnoses, environmental surveillance and the detection of pathogen and biological/chemical terrorism agents. Ultra-high temperature ceramic composites exhibit excellent oxidation and corrosion resistance for hypersonic vehicle applications. Boron-rich solids are also promising candidates for high-temperature thermoelectric conversion. Armor is another very important application of boron-rich solids, since most of them exhibit very high hardness, which makes them perfect candidates with high resistance to ballistic impact. The following topical areas are presented: •Boron-rich solids: science and technology •Synthesis and sintering strategies of boron rich solids •Microcantilever sensors •Screening of the possible boron-based thermoelectric conversion materials; •Ultra-high temperature ZrB2 and HfB2 based composites •Magnetic, transport and high-pressure properties of boron-rich solids •Restrictions of the sensor dimensions for chemical detection •Armor




MAX Phases and Ultra-high Temperature Ceramics for Extreme Environments


Book Description

"This book investigates a new class of ultra-durable ceramic materials, which exhibit characteristics of both ceramics and metals, and will explore recent advances in the manufacturing of ceramic materials that improve their durability and other physical properties, enhancing their overall usability and cost-effectiveness"--




Spark Plasma Sintering: Current Status, New Developments and Challenges


Book Description

Spark Plasma Sintering: Current Status, New Developments and Challenges: A Review of the Current Trends in SPS looks at the progress made in the field of SPS. It includes a review of the scientific mechanisms, materials synthesis and industry applications for this processing technique. Chapters are written by leading experts in the field, encompassing topics surrounding the densification mechanism and microstructure evolution, the classification of high-performance materials, a review of numerical simulation, discussions of new technology advances, such as HP-SPS, flash sintering and related challenges. This book will be useful for researchers, engineers and students within the materials science and engineering fields. Provides significant information on the most relevant research topics currently being addressed by the SPS community Highlights the application of SPS techniques Reviews critical issues that still need to be overcome when utilizing SPS technology




Handbook of Advanced Ceramics and Composites


Book Description

This handbook presents an authoritative account of the potential of advanced ceramics and composites in strategic applications, including defense, national security, aerospace, and energy security (especially nuclear energy). It highlights how their unique combination of superior properties such as low density, high strength, high elastic modulus, high hardness, high temperature capability, and excellent chemical and environmental stability are optimized in technologies within these fields. The handbook is organized according to application type. It allows readers to learn about strategies that have been used in different fields and to transfer them to their own. The book addresses a wide variety of ceramics and their composites, including PZT ceramics, carbon nanotubes, aerogels, silica radomes, relaxor ferroelectrics, and many others.




ZrB2-SiC Based Ultra High Temperature Ceramic Composites


Book Description

In the present research the ZrB2-17vol%SiC, ZrB2-32vol%SiC, and ZrB2-45vol%SiC ultra-high temperature particulate ceramic composites were sintered using both Hot Pressing (HP) and Spark Plasma Sintering (SPS) techniques. The mechanical performance of the ZrB2-SiC composites was investigated using 3- and 4-point bending techniques for measurements of instantaneous fracture strength and fracture toughness. Resonant Ultrasound Spectroscopy was used for measurement of Young's, shear, and bulk moduli as well as Poisson's ratio of the composites. The distribution of thermal residual stresses and the effect of the applied external load on their re-distribution was studied using micro-Raman spectroscopy. Piezospectroscopic coefficients were determined for all compositions of ZrB2-SiC ceramic under study and their experimentally obtained values were compared with the piezospectroscopic coefficients both published in the literature and calculated using theoretical approach. Finally, the novel ZrB2-IrB2-SiC ceramic composites were also produced using Spark Plasma Sintering (SPS), where IrB2 powder was synthesized using mechanochemical route. It is expected that the IrB2 additive phase might contribute to the improved overall oxidation resistance of ZrB2 based ultra-high temperature ceramic composites.




Advanced Multifunctional Lightweight Aerostructures


Book Description

Offers a review of the newest methodologies for the characterization and modelling of lightweight materials and structures Advances in Multifunctional Lightweight Structures offers a text that provides and in-depth analyses of the thermal, electrical and mechanical responses of multi-functional lightweight structures. The authors, noted experts on the topic, address the most recent and innovative methodologies for the characterization and modelling of lightweight materials and discuss various shell and plate theories. They present multifunctional materials and structures and offer detailed descriptions of the complex modelling of these structures. The text is divided into three sections that demonstrate a keen understanding and awareness for multi-functional lightweight structures by taking a unique approach. The authors explore multi-disciplinary modelling and characterization alongside benchmark problems and applications, topics that are rarely approached in this field. This important book: • Offers an analyses of the thermal, electrical and mechanical responses of multi-functional lightweight structures • Covers innovative methodologies for the characterization and modelling of lightweight materials and structures • Presents a characterization of a wide variety of novel materials • Considers multifunctional novel structures with potential applications in different high-tech industries • Includes efficient and highly accurate methodologies Written for professionals, engineers and researchers in industrial and other specialized research institutions, Advances in Multifunctional Lightweight Structures offers a much needed text to the design practices of existing engineering building services and how these methods combine with recent developments.




Hypersonic and High Temperature Gas Dynamics


Book Description

This book is a self-contained text for those students and readers interested in learning hypersonic flow and high-temperature gas dynamics. It assumes no prior familiarity with either subject on the part of the reader. If you have never studied hypersonic and/or high-temperature gas dynamics before, and if you have never worked extensively in the area, then this book is for you. On the other hand, if you have worked and/or are working in these areas, and you want a cohesive presentation of the fundamentals, a development of important theory and techniques, a discussion of the salient results with emphasis on the physical aspects, and a presentation of modern thinking in these areas, then this book is also for you. In other words, this book is designed for two roles: 1) as an effective classroom text that can be used with ease by the instructor, and understood with ease by the student; and 2) as a viable, professional working tool for engineers, scientists, and managers who have any contact in their jobs with hypersonic and/or high-temperature flow.




MAX Phases and Ultra-High Temperature Ceramics for Extreme Environments


Book Description

Ceramics are a versatile material, more so than is widely known. They are thermal resistant, poor electrical conductors, insulators against nuclear radiation, and not easily damaged, making ceramics a key component in many industrial processes. MAX Phases and Ultra-High Temperature Ceramics for Extreme Environments investigates a new class of ultra-durable ceramic materials, which exhibit characteristics of both ceramics and metals. Readers will explore recent advances in the manufacturing of ceramic materials that improve their durability and other physical properties, enhancing their overall usability and cost-effectiveness. This book will be of primary use to researchers, academics, and practitioners in chemical, mechanical, and electrical engineering. This book is part of the Research Essentials collection.