oxide/oxide composites (rus. композиты оксид-оксид) — composites, all ingredients of which are oxides.

Description

Oxide-oxide composites comprising of oxide fibres and oxide matrix, together with SiC-SiC composites, represent the most important type of highly heat-resistant composites that have been actively developed in the last decade.

As all the ingredients in such composites are brittle, methods typical for ceramic matrix composites can be used to prevent cracks under load, and, therefore, provide non-brittle behaviour. For this purpose ingredients forming a weak interface are added to the composite. Such an interface can be formed, for example, by applying a special coating to the fibre, which usually consists of either easily deformable ABO4-type oxides (for example, LaVO4, LaPO4), or highly anisotropic oxides, such as calcium hexaaluminate CaAl12O19. A similar result is achieved by specially organised matrix porosity.

The main efforts of the developers of this material type are focused on composites with nanostructured fibres. This limits the upper temperature of their applications (1,100 – 1,300°C) due to recrystallisation. In addition, there are developments of oxide-oxide composites with single-crystal fibres, whose operating temperature can be higher by 200-300°C.

Authors

  • Lourie Sergey
  • Mileiko Sergey T.

Source

  1. Tu W., Lange F. F., Evans A.G. Concept for a damage tolerant ceramic composite with «strong» interfaces // J. Am. Ceram. Soc. 1996. V. 79. P. 417–424.

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