Development of oxidation/corrosion-resistant composite materials and interfaces

Technical Report · Thu Jun 01 04:00:00 EDT 1995

DOI:https://doi.org/10.2172/115401· OSTI ID:115401

Stinton, D. P.; Besmann, T. M.; Shanmugham, S. ^[1]

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1. and others

Continuous fiber ceramic composites (CFCCs) are being developed for high temperature structural applications, many of which are in oxidative environments. Such composites are attractive since they are light-weight and possess the desired mechanical properties at elevated temperature and in aggressive environments. The most significant advantage is their toughness and their non-catastrophic failure behavior. The mechanical properties of CFCCs have been characteristically linked with the nature of the interfacial bond between the fibers and the matrix. Weakly bonded fiber-matrix intefaces allow an impinging matrix crack to be deflected such that the fracture process occurs through several stages: Crack deflection, debonding at the interface, fiber slip and pull-out, and ultimately fiber failure. Such a composite will fail in a graceful manner and exhibit substantial fracture toughness. Currently, carbon interface coatings are used to appropriately tailor interface properties, however their poor oxidation resistance has required a search of an appropriate replacement. Generally, metal oxides are inherently stable to oxidation and possess thermal expansion coefficients relatively close to those of Nicalon and SiC. However, the metal oxides must also be chemically compatible with the fiber and matrix. If the fiber/interface/matrix system is chemically compatible, then the interfacial bonding stress is influenced by the thermal residual stresses that are generated as the composite is cooled from processing to room temperature. In the current work, thermomechanical computational results were obtained from a finite element model (FEM) for calculating the thermal residual stresses. This was followed by experimental evaluation of Nicalon/SiC composites with carbon, alumina, and mullite interfacial coatings.

• Research Organization: Oak Ridge National Lab., TN (United States)
• OSTI ID: 115401
• Report Number(s): ORNL--6874; ON: DE95015441
• Country of Publication: United States
• Language: English

Related Subjects

01 COAL, LIGNITE, AND PEAT
36 MATERIALS SCIENCE
ALUMINIUM NITRIDES
ALUMINIUM OXIDES
CARBON
COMPOSITE MATERIALS
CORROSION PROTECTION
FABRICATION
FINITE ELEMENT METHOD
MECHANICAL PROPERTIES
MULLITE
NICKEL COMPOUNDS
OXIDATION
PROGRESS REPORT
PROTECTIVE COATINGS
SILICON CARBIDES