Howmet Research Corporation

Howmet Corporation

Mark L Soderstrom

John R Brinegar

Dale A Grumm

Lester G Striker

Dennis J Thompson

Christopher R Hanslits

Bart M Kilinski

Brad J Murphy

Bradley Donaldson

Bradley S Donaldson

Apparatus and method for DS casting using one or more thermal baffle members positionable at a lower open end of a directional solidification casting furnace by movement of a ram on which a mold to be cast is moved relative to the casting furnace. A unique thermal baffle member can be used for each particular series or run of molds to be cast.

Directional solidification method and apparatus

Molten metallic material is cast into a mold that is made with a barrier to reduce gas permeability through a mold wall that forms on its innermost side a mold surface for contacting the molten metallic material. The molten metallic material is gravity cast into the mold residing in a furnace in a casting chamber under a first pressure, such as subambient pressure. Then, a gaseous pressure is provided in the casting chamber higher than the first pressure rapidly enough to reduce or eliminate the presence of localized voids in the casting solidified in the mold.

Investment casting with improved melt filling

Apparatus and method for casting metals and alloys using a pyrometer positioned outside or inside of a casting chamber and relative to a mold heating element in the casting chamber to view a region of a hot melt-filled refractory mold to improve accuracy of the mold temperature readings. The pyrometer is disposed at an elevation outside the casting chamber to view the mold along a viewing path above an induction coil and through an opening in a tubular susceptor disposed about the mold. Alternatively, the tubular susceptor and induction coil both include horizontal openings through which the pyrometer views the melt-filled mold from outside the casting chamber. The pyrometer is positioned to view a uniform profile region of the melt-filled mold having multiple mold cavities as the mold and susceptor are relatively moved.

Casting using pyrometer apparatus and method

Method and apparatus for investment casting wherein a ceramic investment mold is disposed in a chamber and communicates with a melt reservoir connected to the mold and having a reservoir volume for holding enough melt to fill the mold. The melt pour cup reservoir is communicated to the mold via an inverted loop feed gate so that the melt is fed from a lower region of the reservoir through the inverted loop feed gate to the mold upon gas pressurization of the melt in the reservoir. The loop feed gate is configured to have a loop region above the melt level in the reservoir so as to prevent melt flow from the reservoir to the more mold cavities in the absence of pressurization. While residing in the reservoir, oxides and other inclusion-forming particles in the melt can float to the upper surface of the melt, whereby the melt fed from the lower region of the reservoir to the mold via the inverted loop melt feed gate includes reduced amount of inclusion-forming particles.

Investment casting using melt reservoir loop

Method and investment shell mold for casting comprising introducing molten metallic material into an investment shell mold to fill a mold cavity and provide an upper surface of the molten metallic material above the mold cavity. An initially closed, destructible region of the mold then is broken to provide an entry opening through which exothermic material is placed on the upper surface of the molten metallic material to provide a source of molten metallic material to accommodate shrinkage of a casting as it solidifies in the mold cavity.

Investment casting with exothermic material

A gas permeable ceramic investment mold is disposed in a casting chamber and filled with melt to be solidified via a mold melt inlet, such as for example a mold pour cup adapted to receive the melt from a melting crucible in the casting chamber. After the melt is cast into the hot investment mold in the vacuum casting chamber, a pressure cap is positioned in sealing engagement with the mold melt inlet, and gas pressure is introduced through the pressure cap to provide selective or local gas pressure on the melt in the mold without pressure cracking or other damage to the relatively fragile investment mold, while the casting chamber is maintained under relative vacuum or a different pressure from that in the mold.

Investment casting using pressure cap sealable on gas permeable

A ceramic investment mold is disposed in a casting chamber and communicates with a pour cup melt reservoir connected to the mold and having a reservoir volume for holding enough melt to fill the mold. The melt pour cup reservoir is communicated to the mold via an inverted loop feed gate so that the melt is fed from a lower region of the reservoir through the inverted loop feed gate to the mold upon gas pressurization of the reservoir. The loop feed gate is configured to have a loop region above the melt level in the reservoir so as to prevent melt flow from the reservoir to the more mold cavities in the absence of reservoir pressurization. While residing in the pour cup reservoir, oxides and other inclusion-forming particles in the melt can float to the upper surface of the melt, whereby the melt fed from the lower region of the reservoir to the mold via the inverted loop melt feed gate includes reduced amount of inclusion-forming particles. After the melt is introduced into the pour cup, a pressure cap can be positioned in sealing engagement with the pour cup to provide selective or local gas pressure on the melt in the pour cup reservoir to force the melt in the reservoir through the inverted loop feed gate into the mold cavities to fill same.

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Fruitport, MI, United States of America

Mark L Soderstrom