R. G. Cooke - Storming Media

Sol-Gel Processing of Fibre-Reinforced Ceramic Shapes

Authors: R. S. Russell-Floyd; B. Harris; R. W. Jones; R. G. Cooke; T. H. Wang; BATH UNIV (UNITED KINGDOM) SCHOOL OF MATERIALS SCIENCE*

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This paper reviews the current joint research program between the School of Materials Science of the University of Bath and Ceramic Developments (Midlands) Ltd, Corby, into the manufacture of ceramic matrix composites by the sol-gel technique. Development of low shrinkage (< 4%) sol-gel derived matrices has allowed near-net size and shape components to be fabricated by the use of conventional fiber-reinforced plastics technology such as filament winding, resin transfer and ...

Fatigue Damage in SiC/CAS Composites

Authors: F. A. Habib; R. A. J. Taylor; R. G. Cooke; B. Harris; BATH UNIV (UNITED KINGDOM) ZYMOLOGY LAB

While ceramic-matrix composites exhibit none of the fatigue mechanisms that are familiar in metals and polymers, they are, nevertheless, susceptible to reduced working performance under cyclic loading. The main source of this deterioration is the matrix cracking which occurs at low strain levels in brittle/brittle systems where the fibers and matrix possess different stiffnesses. As a result of this cracking, the apparent elastic modulus and Poisson's ratio of the composite ...

Characterization of Damage Onset in Glass-Ceramic Matrix Composite Angle-Ply Laminates

Authors: C. M. A. Davies; B. Harris; R. G. Cooke; BATH UNIV (UNITED KINGDOM) ZYMOLOGY LAB

The tensile mechanical properties of a series of model 0/THETA/O glass-ceramic matrix composite angle-ply laminates have been measured at room temperature in an attempt to characterize the onset of damage in this class of material as a function of fiber orientation. The material selected for this study was a silicon carbide fiber-reinforced calcium aluminosilicate composite. The experimentally determined values of composite elastic modulus, strength and first ply failure stress have ...

Application of Sol-Gel Processing Techniques for the Manufacture of Fiber-Reinforced Ceramics

Authors: R. S. Russell-Floyd; B. Harris; R. G. Cooke; J. Laurie; F. W. Hammett; BATH UNIV (UNITED KINGDOM) SCHOOL OF MATERIALS SCIENCE*

This paper discusses the application of freeze gelation of silica sols for the manufacture of low-cost, net-shape components in ceramic-matrix composites (CMCs). A brief analysis is made of the central features which determine the stiffness, strength, and toughness of composite materials insofar as they may be applied to this particular class of CMCs. The critical processing parameters, relating mainly to the matrix phase, are reviewed and the results of the ...

Interfacial Stress Measurements on Ceramic Matrix Composites

Authors: G. P. Pearson; S. M. Bleay; R. G. Cooke; BATH UNIV (UNITED KINGDOM) SCHOOL OF MATERIALS SCIENCE

A recently published method of quantitative interfacial friction stress analysis was used to characterize the interfaces of a number of composite types, including Pyrex-Nicalon, calcium aluminosilicate (CAS)-Nicalon and barium osumulite (BMAS)-Nicalon. The test involved the compression of a polished slice of the composite cut normal to its reinforcement. The bottom surface of the slice was compressed at constant strain, by being placed on a flat polished silicon carbide plate, while ...

Surface Residual Stresses in Thermal Barrier Coatings

DEC 87

Authors: M. K. Hobbs; R. G. Cooke; B. Harris; H. Reiter; BATH UNIV (ENGLAND) SCHOOL OF MATERIALS SCIENCE*

Insulation of diesel engine combustion chamber components with low conductivity engineering ceramic materials should provide useful benefits in terms of increased engine efficiency and reliability. The low thermal conductivity and high strength and toughness of partially stabilized zirconia has made it a strong candidate for this purpose. Such a material can be applied as an insulating thermal barrier coating or as a monolithic insert component. This paper discusses the application ...

Failure Mechanisms in Silicon Carbide Fibre Reinforced Borosilicate Glass

DEC 87

Authors: B. Ford; R. G. Cooke; S. Newsam; BATH UNIV (ENGLAND) SCHOOL OF MATERIALS SCIENCE*

A study has been made of unidirectional silicon carbide fiber- reinforced borosilicate (Pyrex) glass. Mechanical properties have been determined for three grades of this material: tough, brittle and delaminating. The differences between the materials arose from the different processing parameters employed in their manufacture.