Abstract: Composite shaped articles, well adapted for aerospace applications, include a vitreous matrix and an effective amount of a reinforcing agent therefor, preferably a fibrous and ceramic reinforcing agent, such vitreous matrix being based on silica, alumina, zirconia, an alkali metal oxide and an alkaline earth metal oxide, in the following proportions by weight relative to the total weight of the matrix:______________________________________ (1) 50% .ltoreq. SiO.sub.2 .ltoreq. 80% (2) 7% .ltoreq. Al.sub.2 O.sub.3 .ltoreq. 20% (3) 2% .ltoreq. ZrO.sub.2 .ltoreq. 10% (4) 2% .ltoreq. .SIGMA.A.sub.2 O .ltoreq. 7% (5) 4% .ltoreq. .SIGMA.BO .ltoreq. 10% ______________________________________wherein .SIGMA.A.sub.2 O and .SIGMA.BO represent the respective total amounts by weight of the alkali metal oxides and the alkaline earth metal oxides present in said matrix.

Abstract: Composite shaped articles, well adapted for aerospace applications, include a glass-ceramic and an effective amount of a reinforcing agent therefor, preferably a fibrous and ceramic reinforcing agent, such glass-ceramic matrix being based on silica, alumina, an alkaline earth metal oxide and a rare earth oxide, in the following proportions by weight relative to the total weight of the matrix:5%.ltoreq.MO.ltoreq.40%25%.ltoreq.SiO.sub.2 .ltoreq.70%15%.ltoreq.Al.sub.2 O.sub.3 .ltoreq.70%5%.ltoreq.rare earth oxide.ltoreq.70%wherein M represents an alkaline earth metal.

Abstract: An improved method of manufacturing a composite structure of ceramic material reinforced by refractory fibers is disclosed, whereby the fibers are first embedded in a slip of the ceramic material containing a synthetic resin with good ceramic and fiber wetting properties and a solvent of said resin, the liquid phase is thereafter eliminated from the slip by drying, the synthetic resin is driven from the formed structure by heating, and the fiber-reinforced ceramic material is sintered. The improvement consists in avoiding the use of costly aluminum-nitride powder by initially incorporating an aluminum powder in the slip along with the resin solvent and nitriding the powder in the structure, after drying and firing, but before sintering.

Abstract: A method of manufacturing a sintered silicon carbide ceramic part in which is formed a mixture of carbide powder with a sintering additive based on boron, beryllium or aluminium, and an injection moulding additive comprising a mixture of polystyrene and a wax. A moulded part is manufactured by injection moulding and is then baked and is finally sintered.Polystyrene is used simultaneously as a moulding agent and as a carbonizable substance. When the moulded part is baked it is heated in air to a temperature between 230.degree. C. and 330.degree. C. and is then kept at that temperature for a fairly long time to remove the wax and to reticulate and oxidize the polystyrene.Application to manufacturing dense sintered parts.