Ceramic lamellar composites

Patent metadata

Field	Value
Publication number	US-9796636-B2
Application number	US-201615150612-A
Country	US
Kind code	B2
Filing date	May 10, 2016
Priority date	Nov 7, 2008
Publication date	Oct 24, 2017
Grant date	Oct 24, 2017

Abstract

Disclosed herein is a method of: placing between a cooling element and an opposing surface a slurry of: a dielectric powder containing barium titanate, a dispersant, a binder, and water; maintaining the cooling element at a temperature below the opposing surface to cause the formation of ice platelets perpendicular to the surface of the cooling element and having the powder between the platelets; subliming the ice platelets to create voids; sintering the powder to form the dielectric material; and filling the voids with the polymeric material. The process can produce a composite having: a sintered dielectric material of barium titanate and platelets of a polymeric material embedded in the dielectric material. Each of the platelets is perpendicular to a surface of the composite.

First claim

What is claimed is:

1. A method of forming a ceramic/polymer composite, comprising:
providing a cooling element with a templated surface having a parallel template;
placing a ceramic slurry between the templated surface of the cooling element and an opposing surface parallel to the cooling element, the ceramic slurry comprising:
a powder of a dielectric material,
a dispersant,
a binder, and
water;

maintaining the templated surface of the cooling element at a temperature below the temperature of the opposing surface, resulting in a temperature gradient between the cooling element and the opposing surface, thereby forming ice platelets oriented parallel to the temperature gradient and perpendicular to the surface of the cooling element;
wherein the parallel template of the templated surface of the cooling element is configured to form ice platelets oriented parallel to each other, thereby forming ceramic aggregates aligned parallel to each other between the ice platelets;
subliming the ice platelets to create voids;
sintering the ceramic aggregates to form a ceramic dielectric material; and
filling the voids with a polymeric material, thereby forming a ceramic/polymer composite.

2. The method of claim 1 , wherein the dielectric material comprises barium titanate.

3. The method of claim 1 , wherein the polymeric material is a thermoplastic or a mixable thermoset polymer.

4. The method of claim 1 , wherein the opposing surface is a second cooling element.

5. The method of claim 1 , wherein the difference in temperature between the cooling element and the opposing surface is about 5 to about 70° C.

6. The method of claim 1 , wherein the cooling element is templated by directional abrasion.

7. The method of claim 1 , wherein angles of the ceramic aggregates aligned parallel to each other are within 5° of absolute parallel.

8. The method of claim 1 , wherein the ceramic/polymer composite comprises less than 65 vol % ceramic.

9. The method of claim 8 , wherein the ceramic/polymer composite comprises from 35 vol % to 45 vol % ceramic.

10. The method of claim 3 , wherein the polymeric material is selected from the group consisting of an epoxy, a polyurethane, a polypropylene, and a silicone.

Assignees

• Us Navy

Inventors

• Gorzkowski Iii Edward P
• Pan Ming-Jen

Classifications

• C04B38/0605 Primary

  by sublimating · CPC title

• C04B35/4682

  based on BaTiO3 perovskite phase · CPC title

• C04B35/6261

  Milling · CPC title

• C04B2235/6565

  Cooling rate · CPC title

• C04B38/00

  Porous mortars, concrete, artificial stone or ceramic ware; Preparation thereof (treating slag with gases or gas generating material C04B5/06 {; expanded graphite C04B35/536}) · CPC title