A process for molding prestressed slender and corrugated surface concrete bars to be used subsequently in casting concrete pieces or structures includes, placing them conveniently inside said pieces or structures, in order to also prestress said pieces or structures by gripping and relieving the tensions contained in said bar from the middle section of its longitudinal length.

A method for forming a hole within a ceramic matrix composite component includes forming a first core portion for a ceramic matrix composite component; embedding a hollow member into the first core portion at a desired location; wrapping the first core portion with a first ceramic matrix composite material; inserting a rod through the hollow member and into the first core portion; removing the hollow member; assembling a second core portion to the first core portion such that the rod extends into the second core portion; and wrapping the first core portion and the second core portion with a second ceramic matrix composite material.

A method for producing a ceramic core, and such a core, for preparing the production of a casting having hollow structures. The ceramic core configured to form, making use of a 3D model of digital geometric co-ordinates of the casting. The method involves unpressurized or low-pressure casting of a ceramic core blank, and specifically with an oversize relative to the core according to the geometric co-ordinates, and CNC processing of the core in accordance with the 3D model in a first CNC processing method.

An employed rear mold is comprised of a plurality of mold pieces. The plurality of mold pieces include a first mold piece which forms a first partial internal surface of the internal surface of the rear mold along the entire circumference of the internal surface, and a second mold piece which is located axially forward of the first mold piece and forms a second partial internal surface of the internal surface of the rear mold along the entire circumference of the internal surface. Releasing the molded body includes starting to move the first mold piece rearward in relation to a rear molded portion, and, subsequently to starting to move the first mold piece, starting to move the second mold piece rearward in relation to the rear molded portion, thereby disassembling the rear mold into the plurality of mold pieces.

The invention comprises a concrete form. The concrete form comprises a first panel having a first primary surface for contacting plastic concrete and a second primary surface opposite the first surface, wherein the first panel is made from a rigid plastic sheet or a metal sheet; and a second panel spaced from the second primary surface of the first panel, wherein the second panel is made from a rigid plastic sheet or a metal sheet. The concrete form also comprises a layer of insulating material disposed between the first panel and the second panel. A method of using the concrete form is also disclosed.

The invention comprises a concrete form. The concrete form comprises a first panel having a first primary surface for contacting plastic concrete and a second primary surface opposite the first surface, wherein the first panel is made from a rigid plastic sheet or a metal sheet; and a second panel spaced from the second primary surface of the first panel, wherein the second panel is made from a rigid plastic sheet or a metal sheet. The concrete form also comprises a layer of insulating material disposed between the first panel and the second panel. A method of using the concrete form is also disclosed.

A sprayed article is prepared by thermally spraying ceramic particles of rare earth oxide or fluoride or metal particles of W, Mo or Ta onto an outer or inner surface of a cylindrical carbon substrate to form a sprayed coating, and burning out the carbon substrate, thus leaving the ceramic or metal-base sprayed coating of cylindrical shape having a wall thickness of 0.5-5 mm.

The invention comprises a concrete form. The concrete form compises a first mold for concrete and a second mold for concrete, the first and second molds being in thermal communication with each other. The concrete form also comprises thermal insulating material substantially surrounding the first and second molds but not between the first and second molds. A method of using the concrete form is also disclosed.

The invention comprises a concrete form. The concrete form compises a first mold for concrete and a second mold for concrete, the first and second molds being in thermal communication with each other. The concrete form also comprises thermal insulating material substantially surrounding the first and second molds but not between the first and second molds. A method of using the concrete form is also disclosed.

A monolithic airflow testing mold suitable for mating with a workpiece includes a platform portion formed from a first material having a first hardness. The mold further includes a workpiece mating portion surrounding by the platform portion. The mating portion includes a support region abutting the platform portion and formed from a second material having a second hardness, and a sealing surface positioned above the support region and formed from a third material having a third hardness. The sealing surface is configured to mate with and extend into a hollow portion of the workpiece. The first hardness is different from at least one of the second and third hardnesses.