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US 7,243,700 B2Granted
Method for casting core removal
AssigneeUnited Technologies Corporation
InventorsJames T. Beals, Gary M. Lomasney, Joseph J. Parkos, Jr.
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Abstract
To destructively remove a refractory metal casting core from a cast part the part is exposed to a combination of nitric acid and sulfuric acid.
Claims6
A method for removing a ceramic first casting core and a refractory metal-based second casting core from a cast part comprising:
- a first leaching step for removing a major portion of the first casting core and comprising alkaline leaching and including a plurality of first intervals at a pressure of 0.5 MPa to 1.37 MPa interposed with a plurality of second intervals at ambient pressure;
- and
- a second leaching step for removing a major portion of the second casting core and comprising acid leaching, the second leaching step including:
- immersing in a solution containing nitric acid and sulfuric acid;
- and
- an interval at a temperature of 38-49° C.
3 more elements
Dependencies are inferred from the claim text.