Abstract: The invention provides novel binder, slurry and dry mix compositions for use in the production of investment casting moulds. These compositions comprise water insoluble fibers and significant amounts of uncalcined clay. The compositions display favorable separation characteristics and short drying times. The moulds formed using the compositions have a favourable green strength and conform closely to the wax pattern on which the mould is coated. Also provided are methods of producing the compositions, methods of investment casting mould production utilising the compositions and investment casting coating shells produced using the compositions of the invention.

Abstract: The invention provides novel binder, slurry and dry mix compositions for use in the production of investment casting moulds. These compositions comprise water insoluble fibers and significant amounts of uncalcined clay. The compositions display favourable separation characteristics and short drying times. The moulds formed using the compositions have a favourable green strength and conform closely to the wax pattern on which the mould is coated. Also provided are methods of producing the compositions, methods of investment casting mould production utilising the compositions and investment casting coating shells produced using the compositions of the invention.

Abstract: The present invention relates to improvements in and relating to investment casting. In particular, the invention provides a method of investment casting, comprising the steps of mixing a binder, a refractory material, and a quantity of water-insoluble organic fibres to form a slurry; coating an expendable pattern with a coat of said slurry; and drying said coat or allowing said coat to dry to form a shell. The present invention further provides a refractory slurry for use in the method of the invention, and a kit of ingredients for putting the method of the invention into effect.

Abstract: A method of investment casting is disclosed, which comprises the preparation of a refractory slurry by mixing a binder, a refractory material, and a quantity of water-insoluble organic fibres, and the application of one or more coats of this slurry to an expendable pattern, so as to build up a shell. It has been found that each coat of the slurry thus formed is surprisingly thick, and that a relatively short drying time is required for each coat, hence enabling a shell of desirable thickness to be rapidly built in a small number of “dipping cycles”. The invention also encompasses a kit of ingredients for putting the method of the invention into effect; a shell produced in accordance with this method; and a refractory slurry for use in this method.

Abstract: The present invention relates to improvements in and relating to investment casting. In particular, the invention provides a method of investment casting, comprising the steps of mixing a binder, a refractory material, and a quantity of water-insoluble organic fibres to form a slurry; coating an expendable pattern with a coat of said slurry; and drying said coat or allowing said coat to dry to form a shell. The present invention further provides a refractory slurry for use in the method of the invention, and a kit of ingredients for putting the method of the invention into effect.

Abstract: A method of investment casting is disclosed, which comprises the preparation of a refractory slurry by mixing a binder, a refractory material, and a quantity of water-insoluble organic fibres, and the application of one or more coats of this slurry to an expendable pattern, so as to build up a shell. It has been found that each coat of the slurry thus formed is surprisingly thick, and that a relatively short drying time is required for each coat, hence enabling a shell of desirable thickness to be rapidly built in a small number of “dipping cycles”. The invention also encompasses a kit of ingredients for putting the method of the invention into effect; a shell produced in accordance with this method; and a refractory slurry for use in this method.

Abstract: The present invention relates to improvements in and relating to investment casting. In particular, the invention provides a method of investment casting, comprising the steps of mixing a binder, a refractory material, and a quantity of water-insoluble organic fibers to form a slurry; coating an expendable pattern with a coat of said slurry; and drying said coat or allowing said coat to dry to form a shell. The present invention further provides a refractory slurry for use in the method of the invention, and a kit of ingredients for putting the method of the invention into effect.

Abstract: The present invention relates to improvements in and relating to investment casting. In particular, the invention provides a method of investment casting, comprising the steps of mixing a binder, a refractory material, and a quantity of water-insoluble organic fibers to form a slurry; coating an expendable pattern with a coat of said slurry; and drying said coat or allowing said coat to dry to form a shell. The present invention further provides a refractory slurry for use in the method of the invention, and a kit of ingredients for putting the method of the invention into effect.

Abstract: The present invention relates to a refractory binder that comprises a mixture of aqueous phosphate and silica sol. The silica sol has been found to gel and set in a surprisingly effective and useful way. Preferably, the refractory binder further incorporates a small amount of magnesia as an accelerator. The present invention also provides a method of binding a refractory material such, for example, as alumina, zirconia mullite or aluminium silicate by using a refractory binder according to the invention.

Abstract: The present invention provides a nozzle for teeming molten metal, particularly molten steel, from a tundish or other receptacle, which nozzle comprises an inlet, an outlet, and inner and outer tubular members which define a bore through the nozzle between the inlet and outlet. The nozzle is characterised in that both of said inner and outer tubular members are constructed from refractory materials, and in that the inner member extends within the outer member to the inlet. The inner and outer ceramic layers thus form a "double-layer" of refractory material up to the extremity of the nozzle at the inlet end.

Abstract: A refractory shape is molded on a pattern by pouring over the pattern a mixture of two slurries each of which is stable but which together react to gell. The mixture is formed by merging two slurry streams immediately above the pattern.