USA As Represented by Secretary of the Navy

Curtis A Martin

Inna G Talmy

Gilbert F Lee

Jeffry J Fedderly

Philip John Dudt

James A Zaykoski

Deborah A Haught

David P Owen

David E Johnson

Rodney O Peterson

Kurt P Scharnhorst

Anh H Le

Edward Balizer

Jon Williams Cofield

Bruce J Wells

Inventive manufacture of CrB&#x2014;AlOcomposites is based on pressureless sintering. According to typical inventive practice, CrBpowder and AlOpowder are mixed together in selected volumetric proportions so that the volume of the CrBdoes not exceed 50% of the overall volume of the CrB&#x2014;AlOmixture. The CrB&#x2014;AlOmixture is shaped into a green body. The green body is pressureless sintered in a non-oxidizing atmosphere at a firing temperature in the approximate range between 1600&#xb0; C. and 2050&#xb0; C. The present invention succeeds in preparing, via pressureless sintering, a proportionality-associated range of compositions in the CrB&#x2014;AlOsystem, which is a potentially 'advanced' ceramic system. A typical inventively fabricated CrB&#x2014;AlOcomposite is inventively configured in a complex shape, and has 'advanced' material (e.g., mechanical) properties that are favorable for a contemplated application. Inventive manufacture of ceramic-ceramic composites is thus dually attributed, and uncommonly so, with complex shape-ability and advanced capability.

Pressureless sintering-based method for making a two-phase ceramic composite body

A composite armor including a ballistic armor layer and a directly attached polyurea layer. The polyurea layer is the cured reaction product of an isocyanate curing agent and a mixture of diamines having the general formula:HN-Ph-(C&#x2550;O)&#x2014;O&#x2014;(CH&#x2014;CH&#x2014;CH&#x2014;CH&#x2014;O)&#x2014;(C&#x2550;O)-Ph-NH,wherein in the mixture n in the ranges from 3 to 14 and the weight average value of n is about 9 to 10. Ph represents phenyl. In a preferred embodiment, the polyurea layer is the strike face. The composite armor is useful for light armor applications in which weight is a factor such as military vehicle armor and military boat armor.

Polyurea composite armor

The present invention's stratified composite material system of armor, as typically embodied, comprises a strike stratum and a backing stratum. The strike stratum includes elastomeric matrix material and inventive ceramic-inclusive elements embedded therein and arranged (e.g., in one or more rows and one or more columns) along a geometric plane corresponding to the front (initial strike) surface of the strike stratum. More rigid than the strike stratum, the backing stratum is constituted by, e.g., metallic (metal or metal alloy) material or fiber-reinforced polymeric matrix material. Some inventive embodiments also comprise a spall-containment stratum fronting the strike stratum. The inventive ceramic-inclusive elements geometrically describe any of various inventive modes, including: first mode, having a flat front face and a textured back face; second mode, having a pyramidal front section and a prismatoidal (especially, prismoidal, e.g., truncated pyramidal or prismatic) body section; hybrid mode, combining features of first and second modes.

Composite armor system including a ceramic-embedded heterogeneously layered polymeric matrix

The present invention's stratified composite system of armor, as typically embodied, comprises a backing stratum and a strike stratum that includes elastomeric matrix material and low-density ceramic elements embedded therein and arranged (e.g., in one or more rows and one or more columns) along a geometric plane (or plural parallel geometric planes) corresponding to the front surface of the strike stratum. Some inventive embodiments also comprise a spall-containment stratum fronting the strike stratum. The density of the low-density ceramic material is in the approximate range 2.0-3.0 g/cm. In the strike stratum, the volume ratio of the low-density ceramic material to the elastomeric matrix material is in the approximate range 4-20. The present invention's emulative method for designing an inventive armor system typically involves configurative change of the inventive armor system's low-density ceramic material vis-&#xe0;-vis another armor system's high-density ceramic material so that the respective ceramic material areal densities are equal.

Method for designing and making a plural-layer composite armor system

According to typical inventive practice, precursor particulate is pressed and/or caste and/or molded and/or machined, thereby producing a porous green body of a desired shape. A gas is brought into contact with the porous green body so that, via reaction bonding between the gas and the porous green body, the porous green body becomes a porous reaction-bonded ceramic preform, geometrically corresponding to the porous green body. One or more infiltrant materials, at least one of which is glass or polymer, is/are caused to infiltrate the pores of the RB ceramic perform. The infiltrants are selected from glass, polymer, and metal. The infiltrated preform is permitted to cool and solidify, resulting in an embodiment of an inventive non-ceramic-infiltrated reaction-bonded-ceramic structure. Because of their potential material attributes such as strength, energy dissipation, and low density, the present invention's non-ceramic-infiltrated reaction-bonded-ceramic structures are especially favorable for inclusion in personal/personnel ballistic armor systems.

Lightweight ballistic armor including non-ceramic-infiltrated reaction-bonded-ceramic composite material

Method for making ballistic armor using low-density ceramic material

Composite armor including geometric elements for attenuating shock waves

A method and device for protecting a surface. The device includes modular spaced armor assemblies having a ceramic face plate, a composite backing plate, and a lightweight low-density module therebetween. The modular spaced armor assemblies may be tiled to form a protective arrangement for protecting a desired surface. The lightweight low-density module includes one or more gas filled cavities.

Modular spaced armor assembly

Composite ballistic armor having geometric ceramic elements for shock wave attenuation

A method of preventing thermite reactions during the high temperature incineration (slag temperature greater than 1200.degree. C.) of waste material streams containing aluminum and iron (steel) by mixing a low melting SiO.sub.2 containing material such as water glass or a mixture of sand with NaHCO.sub.3 or Na.sub.2 CO.sub.3 with the waste material.

Method of suppressing thermite reactions in plasma arc waste destruction

A ceramic electromagnetic window made of Si.sub.3 N.sub.4 particles which are bonded together by a metal phosphate binder that is an AlPO.sub.4 binder, a ZrP.sub.2 O.sub.7 binder, or mixtures thereof, wherein the Si.sub.3 N.sub.4 particles comprise from 55 to 85 volume percent of the ceramic material of the electromagnetic window with the metal phosphate binder comprising the remainder. By substituting Si.sub.3 N.sub.4 whiskers for some of the Si.sub.3 N.sub.4 particles a discontinuous fiber composite ceramic electromagnetic window is produced. The electromagnetic window may be a simple shape such as a flat or slightly curved sheet or a more complex shape such as a conical or spherical radome.

Electromagnetic window

A ceramic material made from raw coal fly ash or raw municipal solid waste fly ash and (1) sodium tetraborate or (2) a mixture of sodium tetraborate and a calcium containing material that is triple superphosphate, lime, dolomitic lime, or mixtures thereof.

Ash-based ceramic materials

There is disclosed herein an invention for beneficiation of powered material having superconducting characteristics and processes for carrying it out. The invention involves introducing powdered superconducting material into the vertical field of a magnet wherein particles thereof are levitated according to the Meissner Effect. Particles which are more superconducting levitate at higher elevations or states above the magnet than do particles containing phases that are non-superconducting. Particles that are non-superconducting do not react at all in the magnetic field. Levitated particles are selectively harvested from whatever states desired.

Growing community of inventors

Damascus, MD, United States of America

Curtis A Martin