Abstract: A method of making a casting reinforced with a reinforcement insert, such as a fiber reinforced metal matrix composite insert or intermetallic insert therein, wherein a preformed fiber reinforced metal matrix composite reinforcement insert is clad or covered with a material that is effective to avoid the aforementioned adverse reactions between the insert/melt and any exposed insert fibers/matrix, the clad insert is suspended in the mold cavity, a melt is introduced into the mold cavity about the clad insert, and the melt is solidified about the clad insert to provide a casting of the solidified melt having the clad insert disposed therein to reinforce the casting.

Abstract: A preformed fiber reinforced metal matrix composite reinforcement insert is clad or covered with a material that is effective to avoid the adverse reactions between the insert/melt and any exposed insert fibers/matrix. The clad insert is suspended in the mold cavity and a melt is introduced into the mold cavity about the clad insert. The melt is solidified about the clad insert to provide a casting of the solidified melt having the clad insert disposed therein to reinforce the casting.

Abstract: A method of forming a fine grained equiaxed ingot by melting metal and placing it in a mold having a restriction at the entrance disposed to solidify the metal in the entrance to the mold prior to complete solidification of the metal in the mold such that a shrinkage void is formed below the entrance to the mold. The ingot is then hot isostatically pressed (HIPped) to fully densify the ingot and eliminate the shrinkage void.

Abstract: A method for the production of metal articles resistant to corrosion at elevated temperatures. The method involves the application of a first coating on an article surface, this coating comprising a cobalt, iron or nickel alloy which is compatible with the substrate and which is ductile in character. A second coating highly resistant to corrosion at elevated temperatures is applied over the first coating to form a composite coating, and an elevated temperature treatment follows to provide interfacial bonding and to minimize the detrimental effects of thermal and mechanical stresses encountered during use. The provision of a ductile first layer provides a barrier against degradation of the corrosion resistance of the outer layer and serves as a barrier against detrimental interdiffusion and crack propagation.

Abstract: A process for providing coatings on metal articles whereby the articles will be resistant to corrosion at elevated temperatures. The process involves the application of an overlay on an article surface, the overlay comprising a ductile metal of a composition normally resistant to corrosion at elevated temperatures. An outer layer of aluminide or metal which is resistant to corrosion at elevated temperatures but which is subject to embrittlement at such temperatures is applied to complete the coating. Porosity in the coating is then eliminated and a high integrity corrosion resistant coating not subject to cracking is obtained by heating the article in a gaseous atmosphere to elevated temperature and simultaneously applying isostatic pressure to the article.

Abstract: A turbine nozzle has inner and outer shrouds structurally connected by hollow core members which together with nose and tail inserts retained in the shrouds form airfoil-shaped vanes. Openings in one of the shrouds supply cooling air to the hollow vane cores whose walls have orifices to impinge air upon the inserts. Spent air from the nose insert film cools the core. Air directed at the tail insert divides to flow through holes in the insert and to film cool the insert. Orifices and holes are cast or readily drilled into the parts prior to their assembly. For superior resistance to high temperatures, the inserts are preferably columnar-grained or monocrystalline superalloy castings which are brazed or welded into the shrouds and are replaceable to extend nozzle service life. Alternatively, ceramic or metal inserts are mechanically retained in the shrouds.

Abstract: A method for treating investment cast superalloy castings wherein the portions of the castings which solidify directly against the mold walls comprise a substantially continuous or encapsulating skin of a metallic and/or nonmetallic composition. In such castings, defects in the form of material voids, including defects present immediately beneath the skin, are eliminated by the application of heat and pressure. The castings are heated to temperatures sufficient to achieve metal movement in the form of yield or creep, and a pressure of at least about 10,000 psi is applied by means of a surrounding gaseous atmosphere. The heat and pressure application deforms the material in the area of the voids and consolidates this material to substantially remove the voids and to thereby improve the performance characteristics of the castings.

Abstract: A process for providing coatings on metal articles whereby the articles will be resistant to corrosion at elevated temperatures. The process involves the application of an overlay on an article surface, the overlay comprising a ductile metal of a composition normally resistant to corrosion at elevated temperatures. An outer layer of aluminide or metal which is resistant to corrosion at elevated temperatures but which is subject to embrittlement at such temperatures is applied to complete the coating. Porosity in the coating is then eliminated and a high integrity corrosion resistant coating not subject to cracking is obtained by heating the article in a gaseous atmosphere to elevated temperature and simultaneously applying isostatic pressure to the article.