US Patent 6913064 Refractory metal core

A casting system for forming a gas turbine engine component is provided. The casting system, in a first embodiment, comprises a shaped refractory metal sheet having a plurality of features for forming a plurality of film cooling passages, which features are formed from refractory metal material bent out of the sheet. The casting system for forming a gas turbine engine component in a second embodiment comprises a metal wall having an airfoil shape and a refractory metal core adjacent the metal wall and having a shape corresponding to the shape of the metal wall.