Internal Crystallisation Method to Produce Oxide Fibres and Heat Resistant Composites

Abstract

At present, at least three families of heat resistant materials of an enhanced use temperature are developing: 1. Ceramic matrix composites (CMCs); 2. Metal matrix composites (MMCs);

Composite Oxide Fibres Grown by Internal Crystallisation Method

“…The X-ray diffraction pattern taken from a cross-section of a specimen with α = 0.032 obtained at a pulling rate of 50 mm/min shows the existence of three oxides, Al 2 O 3 , CaAl 12 O 19 (CA6), and Ca 3 Al 2 O 6 . This is in accordance with the observations just described.…”

“…The aim of the present work was to obtain sapphire/CA6 composite oxide fibres by using the internal crystallisation method, which is actually the crystallisation of an appropriate melt in the cylindrical continuous channels of a molybdenum matrix [6,12]. The molybdenum matrix is normally made by diffusion bonding of an assemblage of molybdenum foil and wires, so that two surfaces of the fibre are flat.…”

“…This remains to be carried out. It should be noted that in the Al 2 O 3 -CaO system, there are a number of the complex oxides in addition to CaAl 12 [4]. An occurrence of these oxides in the fibres is not to be excluded.…”

“…The method has been successfully used to produce a large family of single crystalline and eutectic oxide fibres [6]. The state of the art of ICM technology is described in a recent review paper [12].…”

“…A usual way to organise such a kind of the interface is by coating a continuous fibre with an appropriate material. For example, in the case of oxide-fibre/oxide-matrix composites, polycrystalline fibres are often coated with calcium hexaaluminate CaAl 12 O 19 (CA6) [3]. The values of lattice parameters of CA6 are a = 0.47597 nm, c = 2.29918 nm [4], which make the substance mica-like.…”