Abstract: A ceramic armor is disclosed in several embodiments. In a first embodiment, a metal base plate has a metal frame assembled on it having a central opening into which the ceramic material is placed. A cover plate is placed over the frame to enclose the ceramic material on all sides. In a second embodiment, the frame has an open central area that has two crossing walls that define four sub-chambers. Four pieces of ceramic material are placed in the respective sub-chambers and a covering plate is placed over it. In a further embodiment, the frame has a plurality of cavities mechanically formed in it. A ceramic tile or plate is placed in each cavity and a cover plate is placed over the frame. The metal used to encapsulate the ceramic material may, if desired, comprise a Titanium alloy such as Ti-6Al-4V, and the ceramic material may comprise Silicon Carbide, Boron Carbide, Tungsten Carbide, Titanium Diboride or Aluminum Nitride.

Abstract: A ceramic armor is disclosed in several embodiments. In a first embodiment, a metal base plate has a metal frame assembled on it having a central opening into which the ceramic material and stiffening plate are placed. A cover plate is placed over the frame to enclose the ceramic material on all sides. In a second embodiment, the frame has an open central area that has two crossing walls that define four sub-chambers. Four sets of ceramic material and stiffening plate are placed in the respective sub-chambers and a covering plate is placed over them. In a further embodiment, the frame has a plurality of cavities mechanically formed in it. A stiffening plate and a ceramic tile or plate are placed in each cavity and a cover plate is placed over the frame. The metal used to encapsulate the ceramic material may, if desired, comprise a Titanium alloy such as Ti-6Al-4V, and the ceramic material may comprise Silicon Carbide, Boron Carbide, Tungsten Carbide, Titanium Diboride, Aluminum Oxide or Aluminum Nitride.

Abstract: In-situ Si.sub.3 N.sub.4 whisker growth mechanisms have enhanced the microstructure of ceramic materials such as SiC through controlled growth of elongated beta-type Silicon Nitride grains. During liquid phase sintering at temperatures not exceeding 1850.degree. C., alpha-type Silicon Nitride dissolves into the liquid phase and reprecipitates as an elongated or acicular beta modification. The Si.sub.3 N.sub.4 reinforced microstructures can be formed by the controlled recrystallization of beta-type Silicon Nitride. In-situ whisker growth is enhanced or optimized through the use of thermal treatments and/or additions of seed materials. Finely divided beta-type Silicon Nitride particles which are insoluble in the liquid phase during sintering, and therefore have been used to provide nucleation sites for whisker growth are employed. Thermal treatments have been designed to promote directional growth (elongation) as opposed to development of less elongated type grains.

Abstract: A ceramic susceptor with an embedded metal electrode. The metal electrode has multiple apertures, and the ceramic material is cross-linked through the apertures. An electrical connection to the electrode protects the electrode from the environment in the processing chamber. The ceramic may be aluminum nitride, and the metal electrode may be a mesh of molybdenum wires. To form the electrical connection, the susceptor may be heated until an eutectic forms between a conductive connector and the metal electrode. Alternately, a brazing material may be placed between the metal layer and a conductive connector.

Abstract: In-situ Si.sub.3 N.sub.4 whisker growth mechanisms have enhanced the microstructure of ceramic materials such as SiC through controlled growth of elongated beta-type Silicon Nitride grains. During liquid phase sintering at temperatures not exceeding 1850.degree. C., alpha-type Silicon Nitride dissolves into the liquid phase and reprecipitates as an elongated or acicular beta modification. The Si.sub.3 N.sub.4 reinforced microstructures can be formed by the controlled recrystallization of beta-type Silicon Nitride. In-situ whisker growth is enhanced or optimized through the use of thermal treatments and/or additions of seed materials. Finely divided beta-type Silicon Nitride particles which are insoluble in the liquid phase during sintering, and therefore have been used to provide nucleation sites for whisker growth are employed. Thermal treatments have been designed to promote directional growth (elongation) as opposed to development of less elongated type grains.

Abstract: A new silicon carbide material is made following a procedure including hot pressing to provide a finished product having a microstructure with an optimal grain size of less than 7 micrometers. The material exhibits a dominant failure mode of intergranular fracture requiring significant energy for crack propagation. The method of manufacturing is cost-effective by allowing the use of "dirty" raw materials since the process causes impurities to segregate at multi-grain boundary junctions to form isolated pockets of impurities which do not affect the structural integrity of the material. End uses include use as protective projectile-resistant armor.

Abstract: A new silicon carbide material is made following a procedure including hot pressing to provide a finished product having a microstructure with an optimal grain size of less than 7 micrometers. The material exhibits a dominant failure mode of intergranular fracture requiring significant energy for crack propagation. The method of manufacturing is cost-effective by allowing the use of "dirty" raw materials since the process causes impurities to segregate at multi-grain boundary junctions to form isolated pockets of impurities which do not affect the structural integrity of the material. End uses include use as optical and electronic substrate materials.

Abstract: A silicon carbide material is made following a procedure including hot pressing to provide a finished product having a microstructure with an optimal grain size of less than 7 micrometers. The material exhibits a dominant failure mode of intergranular fracture requiring significant energy for crack propagation. The method of manufacturing is cost-effective by allowing the use of "dirty" raw materials since the process causes impurities to segregate at multi-grain boundary junctions to form isolated pockets of impurities which do not affect the structural integrity of the material. End uses include use as protective projectile-resistant armor.

Abstract: A new silicon carbide material is made following a procedure including hot pressing to provide a finished product having a microstructure with an optimal grain size of less than 7 micrometers. The material exhibits a dominant failure mode of intergranular fracture requiring significant energy for crack propagation. The method of manufacturing is cost-effective by allowing the use of "dirty" raw materials since the process causes impurities to segregate at multi-grain boundary junctions to form isolated pockets of impurities which do not affect the structural integrity of the material. End uses include use as optical and electronic substrate materials.