Abstract: An article having a thin wall portion with a thickness of 0.050 of an inch or less, and a surface area of at least 16 square inches is cast as one piece. A mold for the article has a pair of surface areas with a configuration corresponding to the configuration of the thin wall portion of the article and spaced apart by a distance of 0.050 of an inch or less. The mold surface areas have an extent of at least four inches along orthogonal axes with a total surface of at least 16 square inches. Although the extent of the surfaces may vary, depending upon the design of the article to be cast, the thin wall forming portion of the mold has a minimum extent or length, as measured from a center of the thin wall forming portion to the closest edge of the thin wall forming portion, such that the ratio of this minimum distance divided by the thickness is equal to at least 40.

Abstract: A method of forming a mold for use in casting is disclosed. The method includes as a first step forming a positive pattern having a surface the shape of a part to be cast. Next a negative partial pattern is formed having a casting surface complimentary to a selected portion of the surface of the positive pattern and also having a reference surface in a fixed spatial relationship with the casting surface. The casting surface of the negative partial pattern is placed in complimentary engagement with the selected portion of the surface of the positive pattern to form a pattern assembly. A first mold section having a surface complimentary to the reference surface and to the surface of the part is formed by dipping the assembly formed in the preceding step in a ceramic material.

Abstract: A method for bonding graphite sheets to a metallic substrate. The metallic substrate is provided with a coating of low melt metal which forms an intermetallic phase or zone at the interface between the substrate and coating. The coated substrate while in solidified condition is placed in a press between a pair of graphite sheets. Heat is applied to the substrate and graphite sheets while under pressure to a temperature slightly above the melting point of the substrate coating but below the temperature which will destroy the intermetallic interface. The substrate and graphite sheets are cooled while maintained under pressure in the press with the graphite sheets becoming firmly bonded to the metallic substrate by the resolidified metal coating.

Abstract: Coating apparatus for applying a coating liquid to a moving roll. The apparatus has a trough-like pan, longer than the width of the roll surface to be coated, for holding a supply of the coating liquid. A pair of weirs is mounted on the pan which holds the coating liquid partially impounded therebetween. The weirs are spaced closer than the ends of the roll and the width of the roll surface to be coated. The weirs each are formed with a curved concave central portion having a radius the same or slightly larger than the radius of the roll, and with at least one overflow end portion to serve as a spillway. Coating liquid is supplied continuously to the central portion of the pan between the weirs and is drained continuously from the weir overflow end portions. The level of the coating liquid between the weirs is maintained at a higher level than coating liquid outside the weirs.