Patent ID: 7942188

Claim:
A method of making a cast metal article in which a space is disposed, said method comprising the steps of shaping a body of refractory metal particles in a first mold cavity to form a one piece molded refractory metal article having a configuration which is a function of the desired configuration of the space in the cast metal article, removing the one piece molded refractory metal article from the first mold cavity, sintering the one piece molded one piece refractory metal article to form a one piece refractory metal core, positioning the one piece refractory metal core in a second mold cavity having a configuration which is a function of the desired configuration of the metal article to be cast, shaping wax in the second mold cavity with at least a portion of the wax in engagement with at least a portion of the one piece refractory metal core, removing the one piece refractory metal core from the second mold cavity with wax disposed around at least a portion of the one piece refractory metal core, enclosing at least a portion of the wax and at least a portion of the one piece refractory metal core with a covering of mold material, removing the wax from the covering of mold material to form an article mold cavity, filling the article mold cavity with molten metal, solidifying the molten metal in the article mold cavity to form a cast metal article, removing the covering of mold material from around the cast metal article which at least partially encloses the one piece refractory metal core, and removing the one piece refractory metal core from the cast metal article to form the cast metal article in which the space is disposed.