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Walter Krenkel

Bio: Walter Krenkel is an academic researcher from University of Bayreuth. The author has contributed to research in topics: Ceramic matrix composite & Ceramic. The author has an hindex of 28, co-authored 253 publications receiving 3801 citations. Previous affiliations of Walter Krenkel include German Aerospace Center & American Ceramic Society.


Papers
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Journal ArticleDOI
TL;DR: In this article, C/C-SiC composites are considered as the primary materials for hot structures of future launch vehicles and their suitability under extreme thermo-mechanical environments in different structural parts like nose caps, nozzle jet vanes and engine flaps.
Abstract: Ceramic matrix composite materials are being considered the primary materials for hot structures of future launch vehicles. Melt infiltrated composites based on the liquid silicon infiltration process have proven their suitability under extreme thermo-mechanical environments in different structural parts like nose caps, nozzle jet vanes and engine flaps. Considerable progress has been achieved within the last few years to mature the manufacture technology and to tailor the properties of the materials. Among low densities and high damage tolerance behaviour C/C–SiC composites show superior tribological properties predestining these materials for advanced friction systems.

492 citations

Book
01 Jan 1993
TL;DR: High temperature ceramic matrix composites as mentioned in this paper, a.k.a., HVMC composites, have been used in the past for a variety of applications in the field of computer graphics.
Abstract: High temperature ceramic matrix composites , High temperature ceramic matrix composites , مرکز فناوری اطلاعات و اطلاع رسانی کشاورزی

280 citations

Journal ArticleDOI
TL;DR: Ceramic Matrix Composites (CMC) as discussed by the authors is a type of composite material based on carbon fibres and silicon carbide matrices, which have superior tribological properties in comparison to grey cast iron or carbon/carbon.
Abstract: Ceramic Matrix Composites (CMC), based on reinforcements of carbon fibres and matrices of silicon carbide, show superior tribological properties in comparison to grey cast iron or carbon/carbon. In combination with their low density, high thermal shock resistance and good abrasive resistance, these Si-infiltrated carbon/carbon materials, called C/SiC or C/C-SiC composites, are promising candidates for advanced friction systems. Generally, the carbon fibres lead to an improved damage tolerance in comparison to monolithic SiC, whereas the silicon carbide matrix improves the wear resistance compared to carbon/carbon. In combination with new design approaches cost-efficient manufacturing processes have been developed and have lead to successfully tested prototypes of brake pads and disks, especially for passenger cars and emergency brake systems.

268 citations

Journal ArticleDOI
TL;DR: An overview of the design, manufacture, properties, and applications of C/C-SiC ceramics, produced with the liquid silicon infiltration (LSI) process, is given in this article.
Abstract: The demands in space technology originally played the decisive role in the development of carbon fiber reinforced ceramic matrix composites (CMC). Within the last few years, the properties and the manufacturing methods were consistently improved, so that now the industry in general can share in the profits of this new class of composite materials. The liquid silicon infiltration (LSI) process is regarded as one of the most promising processes for industrial products, especially if the aspect of cost is considered. An overview of the design, manufacture, properties, and applications of C/C-SiC ceramics, produced with the LSI process, is given in this paper.

181 citations

Journal ArticleDOI
TL;DR: In this paper, a mathematical technique based on the structure tensor is used to determine the local orientation of fibres in fiber-reinforced materials such as ceramic matrix composites, glass fiber reinforced plastics or reinforced concrete.
Abstract: Computed tomography is a non-destructive testing technique based on X-ray absorption that permits the 3D-visualisation of materials at micron-range resolutions. In this article, computed tomography is used to investigate fibre orientation and fibre position in various fibre-reinforced materials such as ceramic matrix composites, glass fibre-reinforced plastics or reinforced concrete. The goal of this article is to determine the quantitative orientation of fibres in fibre-reinforced materials. For this purpose, a mathematical technique based on the structure tensor is used to determine the local orientation of fibres. The structure tensor is easy to implement and results in a fast algorithm relying solely on local properties of the given reconstruction. In addition, the local X-ray transform is used to denoise fibres and to segment them from the matrix.

147 citations


Cited by
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Reference EntryDOI
31 Oct 2001
TL;DR: The American Society for Testing and Materials (ASTM) as mentioned in this paper is an independent organization devoted to the development of standards for testing and materials, and is a member of IEEE 802.11.
Abstract: The American Society for Testing and Materials (ASTM) is an independent organization devoted to the development of standards.

3,792 citations

Journal ArticleDOI
TL;DR: SiC-based ceramic matrix composites, consisting of carbon or SiC fibers embedded in a SiC-matrix, are tough ceramics when the fiber/matrix bonding is properly optimized through the use of a thin interphase.

1,358 citations

Journal ArticleDOI
TL;DR: X-ray microtomographic imaging is a non-destructive technique for quantifying these processes in three dimensions within individual pores, and as reported here, with rapidly increasing spatial and temporal resolution.

968 citations

Journal ArticleDOI
12 Oct 2019-Polymers
TL;DR: An overview of a diverse range of fibers, their properties, functionality, classification, and various fiber composite manufacturing techniques is presented to discover the optimized fiber-reinforced composite material for significant applications.
Abstract: Composites have been found to be the most promising and discerning material available in this century. Presently, composites reinforced with fibers of synthetic or natural materials are gaining more importance as demands for lightweight materials with high strength for specific applications are growing in the market. Fiber-reinforced polymer composite offers not only high strength to weight ratio, but also reveals exceptional properties such as high durability; stiffness; damping property; flexural strength; and resistance to corrosion, wear, impact, and fire. These wide ranges of diverse features have led composite materials to find applications in mechanical, construction, aerospace, automobile, biomedical, marine, and many other manufacturing industries. Performance of composite materials predominantly depends on their constituent elements and manufacturing techniques, therefore, functional properties of various fibers available worldwide, their classifications, and the manufacturing techniques used to fabricate the composite materials need to be studied in order to figure out the optimized characteristic of the material for the desired application. An overview of a diverse range of fibers, their properties, functionality, classification, and various fiber composite manufacturing techniques is presented to discover the optimized fiber-reinforced composite material for significant applications. Their exceptional performance in the numerous fields of applications have made fiber-reinforced composite materials a promising alternative over solitary metals or alloys.

619 citations

Journal ArticleDOI
TL;DR: In this article, C/C-SiC composites are considered as the primary materials for hot structures of future launch vehicles and their suitability under extreme thermo-mechanical environments in different structural parts like nose caps, nozzle jet vanes and engine flaps.
Abstract: Ceramic matrix composite materials are being considered the primary materials for hot structures of future launch vehicles. Melt infiltrated composites based on the liquid silicon infiltration process have proven their suitability under extreme thermo-mechanical environments in different structural parts like nose caps, nozzle jet vanes and engine flaps. Considerable progress has been achieved within the last few years to mature the manufacture technology and to tailor the properties of the materials. Among low densities and high damage tolerance behaviour C/C–SiC composites show superior tribological properties predestining these materials for advanced friction systems.

492 citations