Abstract: An x-ray tube target includes an annular disk having an outer surface including front and back opposite faces, and an annular focal track fixedly joined to the disk front face for producing x-rays. The disk outer surface is rough away from the focal track, with surface roughness pits having width and depth dimensions greater than a wavelength of peak radiant emission of the target at operating temperature for increasing emissivity of the target to increase thermal radiation cooling thereof.

Abstract: A method and apparatus for casting a molten metallic material in ingot form are provided wherein the molten metallic material is transported to the ingot mold and an upper surface temperature and temperature distribution of the molten metal pool in the casting mold are measured by an imaging radiometer which is disposed external to an inert gas filled chamber enclosing the ingot mold, and is disposed to view the ingot pool surface through a sight port. At least one plasma arc torch is employed to direct an arc at the ingot pool surface, the intensity of which is selectively modulated and the impingement of the arc is simultaneously selectively positioned in order to maintain a desired preselected mold pool surface temperature and temperature distribution thereby yielding a preselected metallurgical structure in the solidified ingot.

Abstract: A method and apparatus for casting a molten metallic material in ingot form are provided wherein the molten metallic material is transported to the ingot mold and an upper surface temperature and temperature distribution of the molten metal pool in the casting mold are measured by an imaging radiometer which is disposed external to a vacuum chamber enclosing the ingot mold, and is disposed to view the ingot pool surface through a sight port. At least one electron beam gun is employed to direct a stream of electrons at the ingot pool surface, the intensity of which is selectively modulated and the impingement of the stream of electrons is simultaneously selectively positioned in order to maintain a desired preselected mold pool surface temperature and temperature distribution thereby yielding a preselected metallurgical structure in the solidified ingot.

Abstract: An apparatus and method for controlling the powder deposition and deposit pattern in a plasma spray process are provided in which an infrared imaging detector and associated processors are employed to provide an image of the temperature distribution of the deposit and to provide an identification of the impact point of the most recent powder deposit, and in which a cyclone separator or other device is used to modulate the flow rate of the carrier gas in which the powder is entrained at the point where the powder and gas are injected into a plasma plume, in order to move the impact point of the powder from the sensed location to a desired location. An injector tube is provided in a cross-flow injection system which may be sized to compensate for variations in the desired injection velocities of particles of different sizes, and the variations in the rate at which such particles are accelerated in the injection tube.

Abstract: The weldability of a part formed from an alloy having low impurity concentrations is determined by initiating an arc between a stationary welding torch and the part using a predetermined set of welding parameters selected to produce a partially penetrating molten weld pool. The natural frequency of oscillation of the molten weld pool is measured a predetermined time following initiation of the arc, and the measured natural frequency of oscillation is compared to empirically determined data for the alloy to determine the weldability of the particular part. Variations in trace element concentrations between different heats of the same alloy affect the three-dimensional geometry of the molten weld pool, and in turn affect its resonant frequency. The invention may be used to adjust the welding parameters to accommodate differences in weldability between different heats of the same alloy.

Abstract: Multispectral imaging apparatus for producing a composite dual wavelength visible/infrared image includes a wavelength independent focus reflective optical system for receiving a visible and infrared radiation from a scene and for providing a focused beam of radiation, a beam splitter for splitting the beam into a beam of visible radiation and a beam of infrared radiation, a visible radiation detector for receiving the visible radiation and for producing a first signal, and infrared radiation detector for receiving the infrared radiation and for producing a second signal, and a signal processing and display system for converting the first and second signals into video signals corresponding to a visible black and white image of the scene and a step-tone or false color infrared image of the scene.

Abstract: The penetration in an arc welding process is measured in real time by monitoring the natural frequency of oscillation of the weld pool. Spatial oscillations are induced in the weld pool by modulating either the shielding gas or the welding current at a plurality of different frequencies, and the light reflected from the pool at a non-specular angle is sensed and processed to determine the natural frequency of oscillation. Both pulse and swept frequency modulations are employed for excitation of the weld pool.

Abstract: An imaging radiometer for high temperature measurements has a sensor head comprised of a solid-state video camera operated in fixed gain mode, preferably one with a charge injection device detector, an infrared filter, and a lens system to image a radiating object on the detector array. Spectral response of the system is limited to 700 to 1100 nanometers or a smaller portion of this near-infrared band. The video signal output of the sensor is processed and object temperature is displayed on a television monitor; alternatively the video signal is presented to a digital frame grabber and converted to a temperature map.

Abstract: A scanning infrared display system capable of variable magnification and high spatial resolution measures the emitted infrared radiation caused by the scanning of a highly collimated energy source beam on the surface to be imaged. The resulting infrared emissions are collected with a high sensivity stationary detector. The display image is formed on a CRT by scanning the object with a raster pattern in synchronization with the CRT and modulating the Z axis CRT potential (brightness) with the infrared detection signal.

Abstract: Multispectral imaging apparatus for producing a composite visible/infrared image includes a wavelength-independent focus reflective optical system for focusing visible and infrared radiation from a scene onto a hybrid visible/infrared radiation detector. The detector comprises an array of visible radiation responsive elements interspersed with infrared radiation responsive elements and provides first and second output signals corresponding, respectively, to the visible and the infrared radiation impinging upon the detector. The first and second signals are converted to a visible black and white image of the scene and a step-tone false color infrared image of the scene. The images are combined in exact spatial registration to produce a composite image comprising a visible image of the scene which is highlighted by the infrared radiation emitted by the scene.

Abstract: A multi-purpose optical sensor operates in the medium-to-far infrared wavelength spectral region to sense the surface temperature of plasma-jet spray coating materials. This plasma itself emits little or no radiation in this region and, accordingly, the output signal from the sensor is used to adjust the electrical input and other variables associated with the plasma spray torch to insure that particles arriving at the substrate surface to be coated are, in fact, in a molten state. The sensor employs infrared filters and, additionally, the sensor is used to monitor not only coating and temperature but also plasma beam divergence and particle seeding density to provide other control functions.

Abstract: An infrared detector is provided with spectral filtering means for direct observation of the arc region during electric arc welding operations. The filter permits direct observation of the weld pool by suppressing almost all of the infrared radiation produced by the arc itself. Were this not the case, the electrical signal output from the infrared detector is totally obscured by the intense infrared radiation from the arc and would thus not permit sufficiently high resolution infrared measurements to be made on the weld pool and the work piece.

Abstract: In an arc welding operation seam tracking is accomplished by determining the level of infrared radiation in a selected bandwidth, from at least two points lying in a direction forward of the arc torch travel and on opposite sides of the seam. Signal levels from the infrared detectors are compared and the difference signal is used to laterally position the arc torch. In this way, automatic seam tracking is accomplished thus facilitating robotic welding processes.