摘要:
The present invention relates to the fabrication of low cost, in situ, porous metallic, ceramic and cermet foam structures having improved mechanical properties such as energy absorption and specific stiffness. Methods of fabricating the structures from compositions including ceramic and/or metallic powders are provided. The flowable compositions also include an immiscible phase that results in pores within the final structure. Furthermore, the structures may be shaped to have external porosity, such as with mesh-like structures.
摘要:
Methods for consolidation and densification of fibrous monolith composite structures are provided. Consolidation and densification of two- and three-dimensional fibrous monolith components having complex geometries can be achieved by pressureless sintering. The fibrous monolith composites are formed from filaments having at least a first material composition generally surrounded by a second material composition. The composites are sintered at a pressure of no more than about 30 psi to provide consolidated and densified fibrous monolith composites.
摘要:
Methods for consolidation and densification of fibrous monolith composite structures are provided. Consolidation and densification of two- and three-dimensional fibrous monolith components having complex geometries can be achieved by pressureless sintering. The fibrous monolith composites are formed from filaments having at least a first material composition generally surrounded by a second material composition. The composites are sintered in an inert gas or nitrogen gas at a pressure of no more than about 30 psi to provide consolidated and densified fibrous monolith composites.
摘要:
A process for continuous composite coextrusion comprising: (a) forming first a material-laden composition comprising a thermoplastic polymer and at least about 40 volume % of a ceramic or metallic particulate in a manner such that the composition has a substantially cylindrical geometry and thus can be used as a substantially cylindrical feed rod; (b) forming a hole down the symmetrical axis of the feed rod; (c) inserting the start of a continuous spool of ceramic fiber, metal fiber or carbon fiber through the hole in the feed rod; (d) extruding the feed rod and spool simultaneously to form a continuous filament consisting of a green matrix material completely surrounding a dense fiber reinforcement and said filament having an average diameter that is less than the average diameter of the feed rod; and (e) depositing the continuous filament into a desired architecture which preferably is determined from specific loading conditions of the desired object and CAD design of the object to provide a green fiber reinforced composite object.
摘要:
Fibrous monolith processing techniques to fabricate multifunctional structures capable of performing more than one discrete function such as structures capable of bearing structural loads and mechanical stresses in service and also capable of performing at least one additional non-structural function.
摘要:
Methods for preparing fibrous monolith composite materials include continuously extruding cell and boundary material compositions. A filament is formed from a cell material composition and passed through a chamber of an extrusion assembly. A boundary material composition is extruded generally about the cell material composition filament and the two material compositions are co-extruded to form an extruded coated filament.
摘要:
Fibrous monolith composites having architectures that provide increased flaw insensitivity, improved hardness, wear resistance and damage tolerance and methods of manufacture thereof are provided for use in dynamic environments to mitigate impact damage and increase wear resistance.
摘要:
Fibrous monolith composites suitable for use in high temperature environments and/or harsh chemical environments are provided, along with methods of preparation thereof. The fibrous monolith composites exhibit such beneficial properties as enhanced strength, corrosion resistance, thermal shock resistance and thermal cycling tolerance.
摘要:
The present invention relates to multilayered ceramic components (10) and methods of fabricating such multilayered architectures. More particularly, the present invention relates to multilayered components having a plurality of dielectric (12) and electrode material (14, 15) layers. The multilayered components are manufactured by coextrusion processes.
摘要:
The present invention provides an inexpensive, open cell, mechanically robust and graphitizable foam preform. The graphitizable foam is produced via a modified standard flower foam formulation. The invention provides a modified formula for such flower foams wherein a mesophase material is incorporated along with a corresponding reduction in the resole component. The mesophase material replaces 30-70% by weight (a target of 50% by weight) of the resole component of the formulation. The formulation is heated to effect foaming of the mixture, and then carbonized to produce an open cell, graphitizable foam preform.