Abstract: A method of magnetically fabricating a particle filled polymer having improved mechanical, electrical, or thermal surface characteristics. Finely divided ferrite particles are first mixed into a hardenable, liquid polymeric material. Next, the particles are magnetically oriented within the material along a selected pattern characterized by a gradient of increasing particle density toward a surface of the material. The polymeric material is then cured into a hardened state in order to affix the pattern of particles therein. The particles may be coated with a hardening material, such as diamond, and attracted to the surface of the material in order to impart desired wear and erosion resistance to the resulting composite. Alternatively, the particles may be coated with a electrically or thermally conducting material, such as silver, and magnetically pulled into intimate contact with one another to impart a high level of electrical or thermal conductivity to the resulting composite.

Abstract: An electromagnetic tagging system is provided for remotely detecting and locating polymeric and other non-conductive structures situated behind barriers, such as underground plastic pipes or containers. The system comprises a fluctuating magnetic field source, a pattern of tags embedded in discrete regions of the wall of the polymeric structure, each tag including an amorphous magnetic metal target for generating a Barkhausen response when exposed to the fluctuating magnetic field source, and a portable detection circuit movable along the ground or other control surface for remotely detecting the Barkhausen response. The amorphous magnetic material in each tag is preferably in the form of a plurality of elongated particles having aspect ratios of at least 3 to 1 and arranged end-to-end.

Abstract: A process for removing paint by high pressure waterjet blasting of painted surfaces wherein the waterjet comprises a ferrofluid or other liquid containing tiny magnetic particles suspended therein. The particles may be in colloidal suspension or be suspended by agitation and are preferably polymer coated. The liquid-magnetic particle mixture lends itself to electromagnetic process control, run-off maintenance and waste processing capabilities. Thereby, the process can employ process control and waste remediation options.

Abstract: A nondestructive method for determining the amount of deformation induced in a material by a compressive force is provided that includes the steps of uniformly dispersing a quantity of a particulate tagging substance in the material whose presence and distribution is detectable by a form of radiant energy, applying a compressive to the material, and then determining the extent to which the material is compressively deformed by transmitting the appropriate radiant energy through the material to determine changes in the density and distribution of the particulate tagging substance. The method may advantageously be applied to determine the extent to which a granular material such as asphalt concrete has been compacted over a roadbed, as well as to determine strain and wear patterns in gaskets formed from elastic materials.

Abstract: A robotic sampling device (32) for cutting part of a tube wall (12) for sampling, containing a cutting head (36), a retrieval assembly (38) and a drive mechanism (40), is used to cut a window or hole (60) in the tube wall (12) and retrieve the tube wall sample (56), where the sample can be mounted onto a separate tube for testing the physical properties of the cut wall portion, and where a video probe (62) and the like can be passed through the window (60) to monitor conditions near the support plates (14) and tube sheets (16).

Abstract: Both a system and method are provided for remotely heating a polymeric material to a selected temperature. The system generally comprises particulate ferromagnetic material dispersed throughout the polymeric material to form a composite, wherein the particulate material has a Curie temperature that corresponds to the selected heating temperature, and a source of microwave energy for remotely applying a beam of microwave energy to the polymeric composite material. Preferably, the particulate ferromagnetic material comprises only about 2 percent of the total composite by weight. The polymeric material may be compliant, thermosettable plastic, and the Curie temperature of the particulate ferromagnetic material dispersed therein may advantageously be above the curing temperature of the polymer, such that the beam from the source of microwave energy may be used to remotely join surfaces or construct joints in composite structures.

Abstract: Both a system and a method are provided which allows an eddy current probe to accurately determine both the proximity and dimensions of non-conductive structures which are normally invisible to such probes. The system comprises a portable target medium that is movable into a known position with respect to the non-conductive structure, and that includes a conductive material that couples strongly with a fluctuating magnetic field, and a movable eddy current probe that emanates a fluctuating magnetic field and which generates a signal indicative of the magnitude of the interaction between the field and the portable target medium from which the distance between the two may be computed. The system may be used to determine the proximity of non-conductive structures such as plastic pipes that have been buried under ground, as well as the dimensions of such non-conductive structures.

Abstract: A nondestructive method for determining the thickness of a non-electrically conductive material is provided that comprises the steps of uniformly dispersing a quantity of a ferromagnetic particulate tagging substance in the material whose presence and distribution is detectable by a form of radiant energy, such as the high-frequency electromagnetic field emanated from an eddy current probe, and then calibrating the output of the eddy current probe with a sample material having a known thickness that has been tagged with the same tagging substance at the same density. The thickness of the material is then determined by comparing the amplitude of electromagnetic coupling with the material with that obtained with the sample. The method may advantageously be applied to determine the thickness of a granular material such as asphalt concrete over a roadbed, as well as the strain and wear patterns in gaskets formed from elastic materials.

Abstract: Both a system and method are provided for remotely heating a polymeric material to a selected temperature. The system generally comprises particulate ferromagnetic material dispersed throughout the polymeric material to form a composite, wherein the particulate material has a Curie temperature that corresponds to the selected heating temperature, and a source of microwave energy for remotely applying a beam of microwave energy to the polymeric composite material. Preferably, the particulate ferromagnetic material comprises only about 2 percent of the total composite by weight. The polymeric material may be compliant, thermosettable plastic, and the Curie temperature of the particulate ferromagnetic material dispersed therein may advantageously be above the curing temperature of the polymer, such that the beam from the source of microwave energy may be used to remotely join surfaces or construct joints in composite structures.

Abstract: Both a system and method are provided for remotely heating a polymeric material to a selected temperature. The system generally comprises particulate ferromagnetic material dispersed throughout the polymeric material to form a composite, wherein the particulate material has a Curie temperature that corresponds to the selected heating temperature, and a source of microwave energy for remotely applying a beam of microwave energy to the polymeric composite material. Preferably, the particulate ferromagnetic material comprises only about 2 percent of the total composite by weight. The polymeric material may be compliant, thermosettable plastic, and the Curie temperature of the particulate ferromagnetic material dispersed therein may advantageously be above the curing temperature of the polymer, such that the beam from the source of microwave energy may be used to remotely join surfaces or construct joints in composite structures.

Abstract: Both a system and a method are provided which allows an eddy current probe to accurately determine both the proximity and dimensions of non-conductive structures which are normally invisible to such probes. The system includes a portable target medium that is movable into a known position with respect to the non-conductive structure, and that includes a conductive material that couples strongly with a fluctuating magnetic field, and a movable eddy current probe that emanates a fluctuating magnetic field and which generates a signal indicative of the magnitude of the interaction between the field and the portable target medium from which the distance between the two may be computed. The system may be used to determine the proximity of non-conductive structures such as plastic pipes that have been buried under ground, as well as the dimensions of such non conductive structures.

Abstract: A device and method for guided testing of an object, and in particular, an internal structural component in an object, using non-destructive ultrasonic techniques is provided. A housing containing at least one ultrasonic transducer probe is adapted to be placed directly on the surface of the object to be tested. Eddy current probes are provided in the housing to guide the ultrasonic probe such that the ultrasonic energy will be directed at the appropriate internal structural design component of the object to be inspected. A microcomputer is then used to record the data obtained using ultrasonic signals and the position on the object using the information designed from the eddy current probes.

Abstract: A method and apparatus for securing or attaching a rotor blade with a turbine rotor cavity by disposing an expanding material between the blade root and the cavity walls. The expanding material comprises a naturally occurring mineral which expands to a great degree when exposed to elevated temperatures. The expanding material may be provided in the form of shims made directly from the expanding material or made from a composition of the expanding material and a binder such as a polymer or elastomer. Alternatively, the expanding material may be provided in the form of a liquid vehicle applied to surfaces of the cavity walls. The expanding material is located at specific positions within the cavity to urge certain surfaces of the blade root against certain surfaces of the cavity walls. In this manner, the blade can be forced into a tight fit and an aligned position, with respect to the rotor, upon expansion of the expanding material.

Abstract: Both a system and a method for determining the length of a discontinuity such as a crack or other fault in the interior wall of a steam generator heat exchanger tube is disclosed herein. The apparatus generally comprises an elongated probe assembly which includes a plurality of eddy current coils mutually separated at known distances with respect to each other along the longitudinal axis of the probe, and an eddy current coil actuating device for separately and independently actuating each of the coils to provide an adjustable electromagnetic sensing field. In the method of the invention, the probe assembly is positioned adjacent a discontinuity and then each eddy current coil, separated by a known distance, is independently actuated and its reading recorded to determine which of the coils actually detects the discontinuity.

Abstract: A diagnostic filter device for monitoring electrically conductive and semiconductive particles entrained by a fluid, composed of:a filter element (4) disposed to receive the fluid and to permit passage of the fluid while retaining particles entrained in the fluid;a component (8) disposed for producing an alternating electromagnetic field which extends across at least one region of the filter element (4); andan eddy current detecting instrument (12) connected to the electromagnetic field producing component (8) for detecting the influence on the field of particles in the filter element region.

Abstract: Both an apparatus and a method for simultaneously inspecting the walls of a tube with both ultrasonic and eddy current probes is disclosed herein. The apparatus generally comprises a cylindrical housing assembly insertable within the tube to be inspected, and a probe carrier rotatably mounted within and helically movable with respect to the housing. The probe carrier holds three ultrasonic probes for transmitting ultrasonic beams which are directly oriented radially, chordally, and axially with resepect to the longitudinal axis of the tube, as well as an eddy current probe for simultaneously inspecting the walls of the tube with electromagnetic lines of flux. The apparatus further includes a helical drive train formed from a lead screw assembly having a motor means, a drive shaft, and a drive sleeve for imparting a helical scanning motion to the probe carrier with respect to the housing.

Abstract: A system and method for nondestructively inspecting and monitoring materials that indicates the structural integrity of the material is disclosed. The inspection method includes the following steps. First, the material to be subsequently monitored, is tagged by dispersing a small amount of finely divided particles throughout the material. The tagged material is then applied in accordance with its application, such as adhesive material to two pieces to be joined to form an adhesive joint. When the adhesive joint or other material is to be inspected, the tagged particles are activated to cause an inherent structural resonance in the tagged material. The activation and structural resonance of the material is then monitored and measured with a probe. Finally, the structure resonance of the material is related to the structural integrity of the adhesive joint, the matrix-reinforcement interface integrity of a composite material, or the state of cure of a resin.

Abstract: Both an apparatus and a method for simultaneously inspecting the walls of a tube with both ultrasonic and eddy current probes is disclosed herein. The apparatus generally comprises a cylindrical housing assembly insertable within the tube to be inspected, and a probe carrier rotatably mounted within and helically movable with respect to the housing. The probe carrier holds three ultrasonic probes for transmitting ultrasonic beams which are directly oriented radially, chordally, an axially with respect to the longitudinal axis of the tube, as well as an eddy current probe for simultaneously inspecting the walls of the tube with electromagnetic lines of flux. The apparatus further includes a helical drive train formed from a lead screw assembly having a motor means, a drive shaft, and a drive sleeve for imparting a helical scanning motion to the probe carrier with respect to the housing.

Abstract: An improved eddy current probe system and method for simultaneously detecting different types of flaws at different depths within a metallic wall, such as a section of Inconel tubing, is disclosed herein. The system comprises a current generator for generating alternating currents of substantially different frequencies, a probe head including first, second and third concentrically arranged coils in separate communication with the current generator, shielding material disposed between the coils for preventing cross talk between each coil and the pulsating magnetic field of the coils adjacent to it, and a detector circuit which may include an inductive bridge for providing an electrical output representative of the impedance changes in the respective coils. In operation, each of the coils conduct currents having substantially different frequencies, the highest frequency being conducted by the smallest-diametered coil and the lowest frequency being conducted by the largest-diametered coil.

Abstract: A process provides a method for attaching a turbine blade to a blade support such as a rotor or rotor disc of a turbine. The root portion of the blade is formed to a shape approximately that of a groove in the surface of the rotor or rotor disc and the root portion of the blade is inserted within the groove. A composition comprising a particulate compound selected from the group consisting of a ceramic, graphite metal, metal alloy and mixtures thereof is positioned between the root portion of the blade and steeples, located one on either side of the groove.