Ceramic matrix composite

About: Ceramic matrix composite is a research topic. Over the lifetime, 7807 publications have been published within this topic receiving 117020 citations.

The Mechanical Behavior of Ceramic Matrix Composites

Abstract: This article summarizes the current understanding of relationships between microstructure and mechanical properties in ceramics reinforced with aligned fibers. Emphasis is placed on definition of the micromechanical properties of the interface that govern the composite toughness. Issues such as the debond and sliding resistance of the interface are discussed based on micromechanics calculations and experiments conducted on both model composites and actual composites.

Flow-Induced Alignment in Composite Materials

Abstract: All chapters end with a section of References. Preface Flow-induced alignment in composite materials: current applications and future prospects A brief survey of composites: Brief history of composite materials, An overview of aligned-fiber composites, Benefits of aligned short-fiber reinforcements, Flow-induced fiber alignment, Applications of aligned-fiber composite, Types of fiber reinforcement, Critical fiber length, Processing issues for producing aligned-fiber composites - Flow processes for producing aligned-fiber polymer matrix composites: Processing of thermoplastic polymer composites, Thermosets, Aligned fiber mats, Blends of liquid crystal polymers and thermoplastics - Flow processes for producing aligned-fiber metal-matrix composites - Flow processes for producing aligned-fiber ceramic matrix composites - Future prospects Fiber-fiber and fiber-wall interactions during the flow of non-dilute suspensions Introduction - Single fiber motion - Orientation characterization - Fiber-fiber interactions: Early work, Diffusion models, Slender body theory-based solution, Stokesian dynamics, Computer simulation/full numerical solutions - Concentrated suspensions - Fiber-wall interactions Summary and outlook Macroscopic modelling of the evolution of fibre orientation during flow Introduction - Theory: Evolution equations, Anisotropic fluid models - Numerical methods: The boundary element method, Solution of the evolution equations - Applications: Flow past a sphere, Injection moulding - Conclusions Flow-induced alignment in injection molding of fibre-reinforced polymer composites Introduction - The injection molding process: Overview, Modeling of mold filling, Velocity profiles in molding filling - Experimental observations of fiber orientation in injection molding: Filling patterns with fiber-reinforced melts, Skin-core structure, Other influences - Prediction of fiber orientation in injection molding: Modeling strategies: prediction of fiber orientation, Modeling strategies: effect of fibres on flow kinematics, Parametric sensitivity studies - Conclusion Control and manipulation of fibre orientation in large scale processing Introduction - Application of SCORIM for welding strength enhancement: Copolyester LCP-containing glass fibres, High temperature cure DMC - Application of SCORIM for physical property enhancement: Glass fibre-reinforced polypropylene, Glass fibre filled copolyester - Control of porosity in thick-section mouldings: Control of porosity and fibre orientation in a variable cross-section bar, Moulding and characterization of a thick-section moulding representing an actuation support structure - Control of fibre orientation in a selection of mould geometries: Injection moulded plaque, Injection moulded fin, Multicavity SCORIM for the production of moulded rings - Extensions of the shear controlled orientation concept Theory and simulation of shear flow-induced microstructure in liquid crystalline polymers Introduction - Shear flow-induced orientation phenomena in rod-like nematic polymers: Leslie-Ericksen continuum theory of nematics, Orientation modes and multistability, Pattern formation under forced convection, Non-equilibrium defect structures - Shear flow-induced molecular alignment phenomena in rod-like nematic polymers: Tensor continuum theory, Alignment-orientation coupling - Conclusions Mesostructural characterisation of aligned fibre composites Introduction: Definition of the measurement problem, Comparison of measurement techniques, Characterisation parameters of fibre orientation states - Optical reflection microscopy: Sample preparation, Overview of microscope and image analyser, An automated large area high spatial resolution design - Confocal laser scanning microscopy: Basic principles, Operational modes for three-dimensional reconstruction - Measurement errors in optical microscopy: Noise in pixellated images, Intrinsic fibre ellipticity, Minimising orientation errors by large angle sectioning, Confocal laser scanning microscope and the apparent depth problem, Stereological issues - Characterisation studies of fibre reinforced composites: Geometrical coefficients, Fibre length distributions, Nearest neighbor angular anisotropy, Fibre misalignments and fibre curvature, Power spectral density of fibre waviness - Future developments: Low level voidage determination, Pattern matching between successive two-dimensional sections, Automation of three-dimensional CLSM for large volume studies, Automated ultrasonic testing for elastic constants determination, Concluding remarks Materials property modelling and design of short fibre composites Introduction - Modelling the stiffness of fully aligned materials: Bounds on moduli, Self-consistent models, Mori-Tanaka model, Halpin-Tsai model, Comparison between models - Effect of fibre aspect ratio on stiffness - Effect of constituent properties on stiffness - Modelling the effect of fibre orientation: Introduction, Transversely isotropic subunit, Transformation of properties and the aggregatge model, Orientation averaging using tensors - Application in design and some results - Conclusions Micromechanical modelling in aligned-fibre composites: prediction of stiffness and permeability using the boundary element method Introduction - Boundary element method: Consideration of dispersed fibres, Massively parallel implementation - Representative results: Stiffness of an elastic rod reinforced with short fibres, Stokes flow across arrays of aligned fibres - Conclusion

Tensile mechanical properties of SiC whiskers

Abstract: An initial evaluation has been made of the tensile mechanical properties of SiC whiskers synthesized by a vapour-liquid-solid process. A micro-tensile tester and associated testing techniques were developed for this purpose. The SiC whiskers exhibit an average tensile strength of 8.40 GPa (1 220 000 psi) and an average elastic modulus of 581 GPa (84 300 000 psi), and were considerably stronger and stiffer than continuous, polycrystalline SiC fibres. These results indicate the significant potential of SiC whiskers as short-fibre reinforcement elements for ceramic matrix composites.

Oxidation Embrittlement Probe for Ceramic-Matrix Composites

Abstract: A test method for probing oxidation embrittlement in ceramic-matrix composite has been devised and demonstrated for three composites: SiC/magnesium aluminosilicate, SiC/SiC, and SiC/Al{sub 2}O{sub 3}. The method identifies a pest temperature T{sub p}. The growth of an embrittled region from the surface, at T{sub p}, has been illustrated. The embrittlement mechanism involves oxygen ingress through matrix cracks and silicate formation at the fibers, causing fiber failure.