Making a metal shape by casting

A pattern when made by a method according to any one of the preceding claims.

A method of making a ceramic shell mould comprising providing a pattern of flexible elastically deformable material of a required shape and supported on a mandrel, applying at least one coating of hardenable refractory material to said pattern to form a rigid shell and removing the mandrel from supporting relationship with the pattern and subsequently removing the pattern from the shell by elastically deforming the pattern and wherein the mandrel is provided with a plurality of retaining elements which extend into the pattern from the outer surface of the mandrel so as to be embedded in the pattern.

A method of making a ceramic shell mould comprising providing a pattern of flexible elastically deformable material of a required shape and supported on a mandrel, applying at least one coating of hardened refractory material to said pattern to form a rigid shell and removing the mandrel from supporting relationship with the pattern and subsequently removing the pattern from the shell by elastically deforming the pattern, wherein the pattern is made by a method comprising the steps of moulding said material in a master mould of a required shape which has a mould cavity defined between inner and outer parts and removing the pattern from the master mould, after the pattern has set, by removing the inner part from within the outer part and then removing the pattern from the outer part, wherein the mandrel is provided by the inner part of the mould.

A method of making a ceramic shell mould comprising providing a pattern of flexible elastically deformable material of a required shape and supported on a mandrel, applying at least one coating of hardenable refractory material to said pattern to form a rigid shell and removing the mandrel from supporting relationship with the pattern and subsequently removing the pattern from the shell by elastically deforming the pattern, wherein the pattern is made by a method comprising the steps of moulding said material in a master mould of a required shape which has a mould cavity defined between inner and outer parts and removing the pattern from the master mould, after the pattern has set, by removing the inner part from within the outer part and then removing the pattern from the outer part, wherein the mandrel is provided separately from the inner part of the mould.

In a centrifugal casting process, including the steps of supplying molten metal into a ceramic shell mould mounted in a container, spinning the container and the shell mould therein about an axis and permitting the metal to solidify in the shell mould and thereafter removing, for example by breaking, the shell mould to expose the metal shape, wherein the ceramic shell mould is made by a method comprising the steps of:

• providing a pattern of flexible elastically deformable material of a required shape and supported on a mandrel,
• applying at least one coating of hardenable refractory material to said pattern to form a rigid shell and removing the mandrel from supporting relationship with the pattern and subsequently,
• removing the pattern from the shell by elastically deforming the pattern and wherein the mandrel is provided with a plurality of retaining elements which extend into the pattern from the outer surface of the mandrel so as to be embedded in the pattern.