Abstract: A magnetic field sensing device comprising at least one magnetic sensor attached to a base structure, rotating member; and at least one flux concentrator mounted on the rotating member; whereby as the rotating member turns, the at least one flux concentrator shields the magnetic sensor so as to modulate the output of the at least one magnetic sensor. A second embodiment comprises a rotating member that rotates about an axis with at least one flux concentrator positioned thereon having a longitudinal axis in the radial direction of the rotating member; and at least one vector-type magnetic sensor fixedly mounted in the near proximity to the axis of the rotating member such that the magnetic field detected is modulated due to the rotation of the rotating member. Optionally, at least one fixed flux concentrator may be positioned along the periphery of the rotating member so as to increase magnetic flux input.

Abstract: A process for producing ceramic flake, fiber and grain materials comprising solidifying a hydrated alumina sol, freeze drying the solidified sol and thereafter sintering the freeze dried material is disclosed. Novel ribbed flake material made by the process of the present invention is also disclosed.

Abstract: A grinding tool is described which comprises self-bonded particles of a ceramic abrasive and has a voids volume of from 5 to 65%.

Abstract: A grinding tool is described which comprises self-bonded particles of a ceramic abrasive and has a voids volume of from 5 to 65%.

Abstract: Zirconia ceramics containing substantial amounts of metastable tetragonal phase crystallites, so that they are tougher than most other ceramics, can be completely comminuted to powders, without applying any mechanical force, by treatment with water or steam at temperatures well above room temperature. This type of comminution is particularly useful for small, often hollow, spheres produced by rapidly solidifying melts of zirconia and a stabilizing oxide such as yttria. These spheres can be almost completely comminuted to a size suitable for wet vibratory milling by treatment for twenty-four hours at 250 C under sufficient steam pressure to maintain some liquid water in equilibrium.

Abstract: The present invention is a fibrous monolithic ceramic product of high deny and a process for making the product. The product has a microstructure of coated fibers with planes of weakness between a core of each coated fiber and its respective coat or between each coated fiber and adjacent coated fibers, thereby toughening the product. The planes of weakness are sufficiently weak to deflect a crack from normal to the plane of weakness to a direction parallel to the plane of weakness. The green body from which the product is formed, can be plastically deformed at room temperature, formed in near-net-shape, and densified by pressureless sintering.

Abstract: A method of reoxidizing a partially-reduced ceramic. The partially reduced eramic is heated in a chamber having a non-oxidizing atmosphere. An oxidizing gas is then introduced into the chamber at a rate which is sufficiently slow that cracking will not occur.

Abstract: BN toughened bodies having isotropic properties are produced by reacting ub.2 O.sub.3, H.sub.3 BO.sub.3 or a mixture thereof with a metal nitride or a mixture of metal nitrides. The process described may be carried out using metal tooling.

Abstract: A particulate mixture of .beta.-silicon carbide, boron carbide and a carbonaceous additive is formed into a green body and sintered producing a sintered body with a density of at least about 85% containing boron carbide in an amount ranging from about 10% to about 30% by weight of the total amount of silicon carbide and boron carbide present.