4results about How to "Wide application temperature range" patented technology

This invention discloses a method for preparing high-temperature resistant polyimide foam material, comprising: preparing a foamable precursor powder using aromatic dianhydride and diamine; performing bilayer extrusion and foaming molding using two single-screw extruders, wherein one extruder extrudes and foams the foamable precursor powder, and the other extrudes fiber-reinforced thermoplastic resin; the two are compounded at a co-extrusion die, and shaped by a shaping die to obtain a polyimide foam composite material with a fiber-reinforced resin layer on the surface; cutting and collecting polyimide foam strips or foam particles of equal length, filling them into a die, and then hot-pressing to obtain the polyimide foam composite material. This invention significantly improves the operability of polyimide foam preparation and simplifies subsequent molding processes. This invention also provides a high-temperature resistant polyimide foam material obtained by the above preparation method, which can simultaneously provide high compressive strength, high modulus, and low density, and is easy to scale up for production.

This invention belongs to the fields of powder metallurgy and materials science and technology, specifically disclosing a preparation process for a high-wear-resistant WC-based composite material. The process involves preparing WC powder, second-phase powder, and graphene material; adding the graphene material to a dispersion medium and performing ultrasonic dispersion; mixing the graphene dispersion with the WC powder and second-phase powder and ball milling; drying the mixture using a vacuum rotary evaporation drying process; and densifying it using a hot-pressing sintering process. This invention enables the WC-based composite material to simultaneously achieve high hardness and high fracture toughness; effectively inhibits oxidative wear of the WC-based composite material at high temperatures, improving its high-temperature wear resistance; and achieves uniform and stable dispersion of the graphene reinforcing phase in the WC matrix, avoiding agglomeration, thereby fully utilizing its strengthening and lubrication effects. The composite material prepared by this invention is particularly suitable for use as high-speed cutting tools, high-temperature molds, and high-temperature moving parts in aerospace applications, and has broad application prospects.

This utility model relates to the field of busbar technology, and particularly to a high-temperature resistant insulating busbar. A high-temperature resistant insulating busbar includes a busbar conductor, the outer surface of which is coated with ceramic silicone, the outer surface of which is coated with fiberglass cloth or a polyimide film, and the outer surface of which is coated with a polyamide insulating layer. This utility model utilizes the complementary properties of polyamide and ceramic silicone to solve the problem of decreased mechanical properties and loss of insulation performance of traditional materials at high temperatures. Through the development of special pretreatment and composite processes, the interfacial bonding force between polyamide and ceramic silicone is enhanced, preventing delamination and peeling under high-temperature thermal stress. This achieves a uniform and dense coating of the insulating layer on the busbar surface, eliminating defects such as bubbles and impurities, and ensuring that the busbar still possesses reliable insulation performance and mechanical strength under high-temperature environments.

This invention discloses a method for preparing oriented long fiber reinforced polyimide foam material, comprising: adding fatty alcohol, aromatic dianhydride and end-capping agent to a solvent for esterification reaction; adding diamine to continue the reaction; drying to remove solvent and obtain RTM-type foamable precursor; mixing and extruding linear thermoplastic polyimide resin with RTM-type foamable precursor, uniformly distributing long fibers on the inner wall of a custom die head, achieving tight encapsulation of oriented long fibers during extrusion; cutting the material to a fixed length and completing volumetric foaming in a foaming mold. This invention also discloses an oriented long fiber reinforced polyimide foam material, using long fibers as reinforcement and a mixed extrudate of linear thermoplastic polyimide resin and RTM-type foamable precursor as the matrix, which improves the flexural strength, compressive strength and toughness of the polyimide foam material, and can be applied to foam sandwich materials in the aerospace field, radar dome sandwich materials, etc.