Rolls-royce Corporation

Martin Richard Perry

Kevin Goodwin

Neil John D'Souza

Neil Dsouza

A mould for casting a component in a directional solidification casting process having a preferred direction of grain growth (non-axial &#x3c;001&#x3e;) comprises a shell defining a cavity for receiving molten material. The cavity defines a three dimensional shape made up of a finished component geometry portion () and a sacrificial geometry portion () wherein the sacrificial geometry portion () includes a notch () which is shaped and positioned so as to, in use, contain high angle grain boundaries between dendritic growth in the preferred direction (non-axial &#x3c;001&#x3e;) and dendritic growth in a competing direction to the preferred direction (axial &#x3c;001&#x3e;) within the sacrificial geometry portion of a casting solidifying in the mould.

Mould for casting a monocrystalline component

Producing a Ni superalloy component in which the superalloy has a &#x3b3; phase matrix containing intermetallic &#x3b3;' precipitates. Providing a Ni superalloy casting of the component; solutioning the component by heat treating the casting under vacuum and/or in an inert atmosphere at a temperature above the &#x3b3;&#x2032; solvus to homogenize the &#x3b3; phase; quenching and ageing the solutioned component to grow intermetallic &#x3b3;&#x2032; precipitates in the homogenized &#x3b3; phase. Before the solutioning step: heat treating the casting to produce a thermally grown oxide on the surface, oxide adherent to supress volatilization of Ni from the surface of the casting during the solutioning heat treatment. Performing the solutioning step under a Ni vapor pressure which is sufficient to supress volatilization of Ni from the surface of the casting during the solutioning heat treatment. During the solutioning heat treatment the component is encapsulated in a container protecting the casting from Si-doped contaminants.

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Derby, United Kingdom

Martin Richard Perry