Abstract:
According to some aspects, a method is provided of casting an object from a mold, the method comprising obtaining a mold comprising a hollow shell of rigid material, the material comprising a thermoset polymer having a plurality of pores formed therein, providing a metal and/or ceramic slurry into an interior of the mold, exposing at least part of the mold to a low pressure environment so that a net flow of gas is produced from the interior of the mold into the low pressure environment. According to some aspects, a method of forming a porous mold is provided. According to some aspects, a photocurable liquid composition is provided, comprising a liquid photopolymer resin, particles of a solid material, in an amount between 30% and 60% by volume of the composition, and a water-soluble liquid.
Abstract:
Solution casting a nanostructure. Preparing a template by ablating nanoholes in a substrate using single-femtosecond laser machining. Replicating the nanoholes by applying a solution of a polymer and a solvent into the template. After the solvent has substantially dissipated, removing the replica from the substrate.
Abstract:
The present invention discloses a method for preparing stable 3D polymer objects with surface micro-nanostructures. The method includes the following steps: Step (1): Synthesizing a thermoset 2D polymer object with surface microstructures. The polymer network contains reversible exchangeable bonds. Step (2): deforming synthesized polymer to an arbitrary desired shape above the reshaping temperature with an external force applied. The permanent reshaping temperature falls in the range of 50-130° C. and external stress is held for 5 min-24 hours Step (3): after cooling, a permanent 3D polymer object with surface microstructure is obtained. Step (2-3) can be repeated for many cycles and the 2D polymer object can be arbitrarily and cumulatively deformed to get a complex 3D structures. The polymer networks contain reversible exchangeable bonds and bond exchange catalysts in the present invention. The method disclosed in present invention is simple and efficient for preparing complex 3D polymer objects with surface micro-nanostructures.
Abstract:
A method and apparatus for forming elongated composite structural members with a desired cross-sectional geometry as taken transverse to the length of the member. An apparatus may include a base with a substantially elongated mandrel mounted thereon. One or more rollers configured to at least partially complementarily engage the mandrel are configure to roll over and press a plurality of plies of composite material onto the mandrel. The rollers may be configured to form intermediate structures which partially conform to the mandrel prior to forming the final structure which substantially completely conforms to the geometry of the mandrel. The rolls serve to both form and debulk the structure. The present invention enables the formation of elongated structural members from resin impregnated materials while maintaining the materials in a substantially uncured state. The formed members may then be cocured with a skin or other composite structure.
Abstract:
Solution casting a nanostructure. Preparing a template by ablating nanoholes in a substrate using single-femtosecond laser machining. Replicating the nanoholes by applying a solution of a polymer and a solvent into the template. After the solvent has substantially dissipated, removing the replica from the substrate.
Abstract:
Methods of forming an elongated composite structural member are provided. One method includes, providing a substantially elongated mandrel having an exterior surface exhibiting a desired geometry. Laying up a first ply of preimpregnated fiber reinforced material over the mandrel. Applying a force to the first ply to establish a desired amount of tension within the first ply and then pressing the first ply onto the mandrel in a conformal manner. This includes passing at least one roller over the mandrel and the first ply while maintaining the desired amount of tension within the first ply. The at least one roller is at least partially complementary in shape with the mandrel.
Abstract:
A composite structure is provided. In one embodiment, the structure includes at least one ply of preimpregnated material formed into a curved elongated member of continuous fibers onto a mandrel. The fibers have a select orientation and the curved elongated member has a defined length. The curved elongated member further has a cross-sectional geometry that varies along the length.
Abstract:
Method of forming a curved composite structure are provided. In one embodiment, the method includes contacting at least one ply of preimpregnated material on a first surface of a curved mandrel. The first surface of the mandrel has a first radius of curvature. The mandrel further has at least one second surface that has a second radius of curvature. A tension gradient is introduced on the ply adjacent to the first radius of curvature and the ply is then pressed over the curved mandrel to form the curved composite structure.
Abstract:
A method and apparatus are provided for forming elongated composite structural members with a desired cross-sectional geometry as taken transverse to the length of the member. An apparatus may include a base with a substantially elongated mandrel mounted thereon. One or more rollers configured to at least partially complementarily engage the mandrel are configured to roll over and press one or more plies of composite material onto the mandrel. The mandrel may be disposed on a rotary table and configured to exhibit a curved elongated geometry to form at least partially curved or arcuate elongated members. The present invention enables the formation of elongated structural members from resin impregnated materials while maintaining the materials in a substantially uncured state. The formed members may then be cocured with a skin or other composite structure.
Abstract:
A method and apparatus are provided for forming elongated composite structural members with a desired cross-sectional geometry as taken transverse to the length of the member. An apparatus may include a base with a substantially elongated mandrel mounted thereon. One or more rollers configured to at least partially complementarily engage the mandrel are configured to roll over and press one or more plies of composite material onto the mandrel. The mandrel may be disposed on a rotary table and configured to exhibit a curved elongated geometry to form at least partially curved or arcuate elongated members. The present invention enables the formation of elongated structural members from resin impregnated materials while maintaining the materials in a substantially uncured state. The formed members may then be cocured with a skin or other composite structure.