Abstract: A method and apparatus for cleaning internal channels in an article are presented, with the method comprising providing an article that comprises at least one internal channel. The at least one internal channel comprises at least one inlet port and at least one outlet port. The method further comprises providing a cleaning apparatus, and this cleaning apparatus comprises a cleaning fluid, a reservoir containing the cleaning fluid, a transmitter of vibrational energy projecting into the reservoir the transmitter comprising a transmitter tip and a source of vibrational energy coupled to the transmitter, with the vibrational energy comprising a frequency and a wavelength. The reservoir of the provided apparatus comprises an interface adapted to accommodate attachment of the reservoir to the article, and this interface comprises an orifice to allow fluid communication between the reservoir and the at least one internal channel of the article.

Abstract: A method and apparatus for cleaning internal channels in an article are presented, with the method comprising providing an article that comprises at least one internal channel. The at least one internal channel comprises at least one inlet port and at least one outlet port. The method further comprises providing a cleaning apparatus, and this cleaning apparatus comprises a cleaning fluid, a reservoir containing the cleaning fluid, a transmitter of vibrational energy projecting into the reservoir the transmitter comprising a transmitter tip and a source of vibrational energy coupled to the transmitter, with the vibrational energy comprising a frequency and a wavelength. The reservoir of the provided apparatus comprises an interface adapted to accommodate attachment of the reservoir to the article, and this interface comprises an orifice to allow fluid communication between the reservoir and the at least one internal channel of the article.

Abstract: A nondestructive evaluation method is described for ultrasonic evaluation and detection of features in polycrystalline materials, such as grain orientation (e.g. texturing) or grain boundary orientation. The method may, for example, be employed to detect diffusion bonds that contain undesirable planar grain boundary arrays. The method utilizes time of flight statistics gathered from reflections associated with incident ultrasonic signals directed into a plurality of locations within the material.

Abstract: The method of producing a binary flaw-no flaw image of an object, including employing an ultrasonic data acquisition system to obtain data values f(i,j) which define a C-scan image (F) of the object, dividing the C-scan image (F) into a plurality of subimages (G.sub.k for k=1,2, . . . ,K), determining regional threshold levels y(k) for each of the plurality of subimages, using said regional threshold levels y(k) to determine pixel threshold levels t(i,j) for each pixel (i,j) of the image (F) by interpolation, and generating a binary flaw-no flaw image (B) by assigning binary values thereto based on a comparison between the pixel threshold levels t(i,j) and data values f(i,j), thereby providing a method which achieves a high probability of flaw detection and a low probability of false flaw indications.

Abstract: A method and circuit for improved digitization of waveforms having a large dynamic range, including selecting a signal threshold value which partitions the dynamic range of the waveform into a small signal region and a large signal region; sampling the waveform to obtain a sampled signal therefrom at a given sampling frequency; for each sampled signal, comparing the sampled signal with the signal threshold value to determine whether the sampled signal is within the small signal region or the large signal region; and directly digitizing the sampled signal if the sampled signal is within the small signal region or differentially digitizing the sampled signal if the sampled signal is within the large signal region, wherein differentially digitizing the sampled signal includes digitizing a value representing the difference between the sampled signal at a present sampling instant and a previous sampling instant.

Abstract: A multizone ultrasonic inspection apparatus and method of employing the apparatus for inspecting titanium billets is provided, in which a plurality of ultrasonic transducers having focal zones of increasing depth are positioned to examine a cylindrical billet of titanium through the thickness of the billet. The focal zones partially overlap the adjacent focal zones, thus assuring complete examination through the thickness of the entire billet. The reflected signals from the transducer receivers are processed into digital form in order to be used in generating an image of the billet undergoing inspection, and to be used in storing the image data in, for example, a hard disk or an optical disk.

Abstract: A system and method for using the detector to differentiate neutron attenuating material from high x-ray attenuating material in an object. The inspection system is used to detect the presence of nitride in titanium sponge nuggets or residual core material in a hollow-cast turbine engine blades. The inspection system uses a dual radiation source to alternately emit neutrons and x-rays or gamma rays at the object under inspection. A dual modality gas ionization detector detects the radiation passing through the object and sends the detected radiation to a processing means for image generation. The generated image is displayed on a display, enabling objects formed with low and high attenuating material to be distinguished.

Abstract: An eddy current surface inspection array probe and method for detecting cracks and flaws in aircraft skin metal immediately surrounding rivets, without requiring rivet removal or manual scanning. The array probe includes a circular array of small sense coils positioned beneath a much larger drive coil encased in ferrite. The sense coils are differentially connected in pairs such that the signals from two sense coils located on opposite sides of the rivet (180.degree. apart) subtract to produce a resultant output signal. During operation, the probe is positioned concentrically over the rivet and data acquired from all sense coil pairs. If no cracks or other defects are present, all sense coil pairs produce a null (zero) signal. If a crack exists, some sense coil pairs (the exact number depending on the crack length, number of sense coils, and sense coil spacing) produce a non-zero signal.

Abstract: A dual modality gas ionization detector for differentiating neutron attenuating material from high x-ray attenuating material in an object. The dual modality gas ionization detector uses .sup.3 He and Xe gases pressurized in an ionization chamber to detect neutrons x-rays or gamma rays. The dual modality gas ionization detector is used in an inspection system for detecting, characterizing, or differentiating small amounts of neutron attenuating materials in objects composed primarily of materials of large attenuating x-ray material.

Abstract: A method of making metal alloy articles having inclusions which are predetermined and controlled with respect to their size, shape, composition, crystal structure and location and orientation within the article is disclosed. In a preferred embodiment, the method of making is directed toward titanium alloy articles containing synthesized hard-alpha inclusions of titanium/nitrogen, titanium/oxygen and titanium/oxygen/nitrogen alloys.

Abstract: An ultrasonic measurement device and a method for a non-destructive evaluation of polymer composites having discontinuous fibers distributed therein. The device has one or a plurality of substantially matched pairs of transducers disposed on wedge shaped focuser and a relay, the focuser and relay each have their impedances substantially matched to that of the polymer composite being analyzed. The device is placed on a surface of the composite with the apexes of the focuser and relay in close contact with the surface.

Abstract: An improved two membered substantially crack-free water jet mixing tube of an abrasive water jet cutting device and a method of its preparation. The method comprises chemically vapor depositing diamond layer on a funnel shaped support member to form an inner member of the mixing tube, separating the inner member from the support member, depositing and then cooling an outer member on the outer side of the inner member to produce a compressive stress on the inner member that substantially prevents formation cracks on the inner member. The inner side of the inner member has a smooth bore having a microcrystalline structure and the outer member has a higher coefficient of thermal expansion than diamond. The invention is also directed to a water jet cutting device that incorporates the aforementioned improved substantially crack-free water jet mixing tube.

Abstract: Nuclear fuel cladding tube end plug welds are ultrasonically scanned to develop data indicative of weld thickness, weld penetration, and the existence and size of any included feature, such as pores. A computer analyzes the data to determine critical weld characteristics which are then tested against established quality assurance standards to see if the end plug weld is acceptable, all on an automated production line basis.

Abstract: Nuclear fuel cladding tube end plug welds are ultrasonically scanned to develop data indicative of weld thickness, weld penetration, and the existence and size of any included feature, such as pores. A computer analyzes the data to determine critical weld characteristics which are then tested against established quality assurance standards to see if the end plug weld is acceptable, all on an automated production line basis.

Abstract: Wafers which are direct bonded to each other in accordance with prior art processes suffer from voids at their bonded interface. Annealing such composite structures at high temperature and high pressure (for silicon wafers preferably about 1,100.degree. C. and 15,000 psi) eliminates all voids which are not a result of the presence of a particle on one of the wafers at the time of mating.

Abstract: An apparatus for monitoring the curing of a fiber reinforced composite plastic which is cured at temperatures of the order of 350.degree. C. and an ultrasonic transducer assembly useful in the apparatus. The transducer assembly comprises a lithium niobate piezoelectric element having anisotropic coefficients of thermal expansion which is mounted on a metal base of the transducer assembly by means of a layer of structured copper. The structured copper is thermo-compression diffusion bonded to the lithium niobate element and to the metal base, and is compliant in a transverse direction to compensate for differential thermal expansions while affording good electrical and thermal conductivity and good acoustic coupling between the lithium niobate element and metal base.

Abstract: A broadband 25 to 50 MHz spherically focused ultrasonic transducer is placed on the tip of a catheter such that ultrasonic images of arteries and plaque are produced by introducing the catheter into arteries of patients. The high frequency transducer has thin piezoelectric polymer film as the transducing element and is adhered to a depression in the reduced cross section catheter tip. A coaxial cable in the catheter connects the transducer to an external signal source and a display for the received signals. The diagnosis and characterization of arterial disease is most often coupled with a therapeutic technique such as balloon angioplasty.

Abstract: An apparatus for monitoring the curing of a fiber reinforced composite plastic which is cured at temperatures of the order of 350.degree. C. and an ultrasonic transducer assembly useful in the apparatus. The transducer assembly comprises a lithium niobate piezoelectric element having anisotropic coefficients of thermal expansion which is mounted on a metal base of the transducer assembly by means of a layer of structured copper. The structured copper is thermo-compression diffusion bonded to the lithium niobate element and to the metal base, and is compliant in a transverse direction to compensate for differential thermal expansions while affording good electrical and thermal conductivity and good acoustic coupling between the lithium niobate element and metal base.

Abstract: The bond between a structured copper heat sink member and a semiconductor wafer is inspected for voids and unbonds by a focused ultrasonic pulse transmission method. The small focused spot of ultrasound is transmitted along the structured copper strands and is attenuated in the lateral direction. The absence of a received pulse or a significantly reduced amplitude signal, as the assembled device is scanned with acoustic pulses, indicate flaws in the bond.

Abstract: Concentrated sunlight impinges on a large area photovoltaic device which is bonded to a highly pliable and thermally and electrically conductive structured copper strain relieving member; the lower face of the structured copper is sealed to a fluid cooled metal heat sink. Large power densities of sunlight are absorbed without appreciable temperature rise. The structured copper accommodates to the difference in expansion between the metal heat sink and the semiconductor wafer. Three embodiments utilize a single planar junction diode, an interdigitated diode, and series connected isolated junction diodes.