Casting method for turbine blade

摘要

In order to more effectively utilise seed crystals 35, 55 to achieve a single crystal grain orientation for a component without the problems of utilising a helix constriction previously necessary to avoid epitaxial grain competition and growth. The present invention creates a wax component pattern 30. This pattern 30 comprises integral sections of wax for a mould component section and for a spacer section with the seed crystal 35 or holder for that crystal therebetween. This pattern 30 is then utilised in order to form a final refractory mould within which the component is formed. By appropriate choice of the spacer section 32, an appropriate spacing between an upper surface of the seed 55 which will be the initial interface with molten castable material to form the component and a chiller surface through which heat is transferred can be determined in order to achieve successful transfer of the seed 55 orientation to the formed component.