| 摘要 |
<p>A method for casting long thin metal articles (10) is described. A particular embodiment is directed to the casting of seals that are used in the low pressure turbine section of a gas turbine engine. The method first involves forming a mold (38), and then preheating the mold (38) so that the temperature towards the upper portion (84) of the mold (38) is closed to the liquidus temperature of the metal composition being cast. The temperature of the bottom portion (82) of the mold (38) is below the solidus temperature of the metal cavity, the mold heating system (68) preferably is moved at a selected rate so that the portion of the mold (38) being heated by the furnace (68) is slowly decreased. Withdrawal rates slower than about 30 inches per hour produce satisfactory casting results.</p> |
