Journal ArticleDOI
Microstructure Evolution and Reaction Mechanism of Biomorphous SiSiC Ceramics
Cordt Zollfrank,Heino Sieber +1 more
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TLDR
The evolution of the microstructure during reactive Si melt infiltration was assessed by infiltration experiments at various times and investigated by X-ray diffraction as well as light scanning electron and transmission electron microscopy in combination with elemental analysis by energy-dispersive Xray spectrometry.Abstract:
Liquid Si infiltration (LSI) of beech wood-derived biocarbon (CB) templates at 1550°C yields biomorphous SiSiC ceramics with the morphology of the initial biological preform. The biomorphous SiSiC ceramic consists of solidified Si in the cell lumina, polycrystalline β-SiC and residual carbon islands located at the position of former wood cell walls. The evolution of the microstructure during reactive Si melt infiltration was assessed by infiltration experiments at various times and investigated by X-ray diffraction as well as light scanning electron and transmission electron microscopy in combination with elemental analysis by energy-dispersive X-ray spectrometry. Four different stages of the reactive infiltration process could be distinguished, starting with a heterogeneous nucleation of nano-grained SiC on the pore surfaces of the CB template by a Si vapor phase reaction below the Si melting temperature. After spontaneous Si melt infiltration, a stepwise reaction results in the simultaneous formation of a nano-grained SiC layer and a coarse-grained SiC phase on the inner pore surfaces. Further reaction proceeds slowly by diffusion of the reactants through the formed SiC layer and the microstructure evolution is dominated by dissolution and re-crystallization processes.read more
Citations
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Journal ArticleDOI
Microstructural evolution during the infiltration of boron carbide with molten silicon
TL;DR: In this paper, the core-rim structure of reaction-bonded boron carbide composites (RBBCs) was investigated and validated by additional experimental observations and by a thermodynamic analysis of the ternary B-C-Si system.
Journal ArticleDOI
Microstructure and tribological properties of advanced carbon/silicon carbide aircraft brake materials
Shangwu Fan,Litong Zhang,Yongdong Xu,Laifei Cheng,Guanglai Tian,Shaochang Ke,Fang Xu,Haiping Liu +7 more
TL;DR: In this paper, the structural characteristics of carbon/silicon carbide (C/SiC) aircraft brake materials were studied by means of optical microscopy, SEM, XRD and TEM, and their frictional properties were investigated using a full-size aircraft wheel and brake assembly on a fullscale dynamometer.
Journal ArticleDOI
Fabrication and characterization of carbon fiber reinforced SiC ceramic matrix composites based on 3D printing technology
TL;DR: In this paper, a novel method has been developed to fabricate carbon fiber reinforced SiC (Cf/SiC) composites by combining 3D printing and liquid silicon infiltration process.
Journal ArticleDOI
Thermal Conductivity of Porous Silicon Carbide Derived from Wood Precursors
TL;DR: In this article, the thermal conductivity of bioSiC from five different precursors was experimentally determined using flash diffusivity and specific heat measurements at temperatures ranging from room temperature to 1100°C.
Journal ArticleDOI
Precursor selection and its role in the mechanical properties of porous SiC derived from wood
TL;DR: In this article, the compressive strength, elastic modulus, and fracture toughness of porous SiC derived from wood precursors were measured, and the amount of unreacted carbon was found to be a function of porosity and pore size distribution, which are dependent on the precursor wood.
References
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BookDOI
Wood: chemistry, ultrastructure, reactions.
Dietrich Fengel,Gerd Wegener +1 more
TL;DR: The anatomy and chemistry of wood are described in detail, and with extensive reference to the literature, under the following headings: Introduction; Structure and ultrastructure; Chemical composition and analysis of wood; Cellulose; Polyoses (hemicelluloses); Lignin; Extractives; Distribution of the components within the wood cell wall; Constituents of bark; Reactions in acidic medium; reactions in alkaline medium; Influence of temperature; Degradation by light and ionizing rays; Microbial and enzymatic degradation; Aging and fossilization; Pul
Journal ArticleDOI
Carbonization and graphitization
TL;DR: In this paper, a review of recent electron microscope observations relating to the carbonization and graphitization of a variety of carbonaceous precursors is made and the different behaviors of graphitizing and non-graphitizing carbons are elucidated, and the effect of sulphur as a crosslinker is determined.
Journal ArticleDOI
Biomorphous ceramics from lignocellulosics
TL;DR: In this article, fundamental aspects of anatomy of wood and molecular structure of wood cell wall affecting the bio-organic-inorganic conversion process are reviewed, and basic approaches to convert the native biopolymeric materials into non-oxide as well as oxide ceramic products include pyrolytic decomposition resulting in a porous carbon replica (template) which may subsequently be reacted to form carbide phases or may be infiltrated with non-reacting sols or salts which can further be processed to yield oxide reaction products.
Journal ArticleDOI
C/C-SiC Composites for Advanced Friction Systems
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.
Journal Article
Fiber-reinforced silicon carbide
TL;DR: In this article, the fabrication de composites de SiC renforces de fibres ceramiques par impregnation de vapeur chimique, liaison reactive par improglobalisation subsequente et decomposition thermique des composes organosilicies.