Howmet Corporation

Howmet Turbine Components Corporation

William R Freeman

Gregory N Colvin

Donald E Larsen, Jr

Stewart J Veeck

Louis E Dardi

John R Brinegar

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.

Method of making composite castings using reinforcement insert cladding

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.

In making a dual alloy gas turbine rotor, a plurality of superalloy components are formed to include an airfoil having a directionally solidified columnar grain structure or a single crystal grain structure. A boron-bearing melting point depressant material is applied to the inner surface and a side surface of the components. The components are arranged side-by-side in an annular array with the first side surface of one component juxtaposed to the second side surface of an adjacent component and with the inner surfaces defining a spray-receiving surface. The airfoils extend in a radial axis or direction of the array while the spray-receiving surface extends in a circumferential direction of the article. A sealing member is positioned adjacent an axial end of the array of the components to close off that end and form a spray-receiving cavity. Boron-bearing melting point depressant material is provided between the sealing member and the end of the array. The array/sealing member is heated to form an exposed liquid layer on the spray-receiving surface at the onset of plasma spraying of a molten metal and also to form a fusion joint between the juxtaposed first and second surfaces of the components and between the sealing member and the end of the array. A superalloy hub material is plasma sprayed onto the exposed liquid layer to buildup up a deposit in the cavity that forms a hub precursor of the rotor. The array/deposit is hot isostatically pressed using pressurized gas and then heated treated to develop desired properties in the components and the hub precursor.

Method of making a dual alloy article

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.

Method of forming dense ingots having a fine equiaxed grain structure

A high temperature alloy displaying excellent elevated temperature properties as well as low strategic metals content. Based on the iron/aluminum system, the alloy contains about 10 to 19% aluminum, 2 to 8% titanium, from about 0.5 to 10% molybdenium, from 0.1 to 1% hafnium and the balance substantially iron.

Heat resistant alloys with low strategic alloy content

A method for producing cast, superalloy, ferrous and titanium articles comprising the formation of a material void in the cast article, for example by utilizing a core during the casting operation or by machining a void after casting. The void is sealed relative to the surrounding atmosphere and the article is then subjected to an elevated temperature and pressure treatment in a gaseous atmosphere whereby the metal in the area of the void will yield so that the void is partially or totally eliminated. The pressure application is carried out at a temperature such that local deformation of the cast structure occurs in the region previously occupied by, and adjacent to, the void whereby a fine-grained recrystallized structure is developed in this section. Grain refined cast articles are characterized by superior low-cycle fatigue and tensile properties.

Growing community of inventors

Easton, CT, United States of America

William R Freeman