General Electric Company

Thomas E Bantel

David F Lahrman

John W Devitt

John F Halase, Iii

Harry Israel Ringermacher

Donald Robert Howard

Thomas William Birdwell

Bryon Edward Knight

David Charles Mack

William George Patterson

Janet S Kania

Joseph M Sparks

Thomas R Edwards

A method for identifying types of flaws in a composite object includes: a) rapidly heating the surface of the object; b) recording pixel intensities in a sequence of IR images; c) determining temperature-versus-time data for each of the pixels from the IR images; and d) determining what type of flaw if any corresponds to each of the pixels using the temperature-versus-time data determined in step (c). A contrast curve derived from the temperature-versus-time data may be used in determining what type of flaws if any corresponds to each of the pixels. The contrast curve may be determined by subtracting a synthetic reference curve from a temperature time curve from the temperature-versus-time data. The types of flaws may be determined from size and/or shapes of peaks in the contrast curves. Some flaws are delaminations, layers of porosity, and uniformly distributed porosity.

Characterization of flaws in composites identified by thermography

A system for radiographic inspection of an object includes a radiation source located on one side of the object and a radiation detector located on another side of the object, being positioned to receive radiation from the radiation source. At least one motion sensor is associated with the radiation detector, the radiation source, or the object, for detecting motion. The magnitude of motion of the components is compared to a pre-established limit value. The imaging process is conducted when the magnitude of any motion is less than the limit value.

Radiographic inspection of airframes and other large objects

A method for nondestructive/noncontact detection of alpha case on a surface of a workpiece made of titanium or a titanium-based alloy. Infrared radiation is reflected off of a selected portion of the workpiece surface and sensed by a detector which may comprise a scanning infrared radiometer, an infrared camera, or a spot radiometer. The presence of any alpha case in the selected portion of the workpiece surface is detected by comparing the intensity of the reflected infrared radiation to a predetermined intensity known to be indicative of the absence of alpha case. An image of the reflected infrared radiation may be created and the step of detecting the presence of alpha case may include the step of comparing the intensity of the reflected infrared radiation within the image to the predetermined intensity. According to a preferred embodiment, a target may be disposed between the source of the infrared radiation and the workpiece surface so as to create a predetermined pattern within the image. In this embodiment, the step of detecting may further include the step of comparing the clarity of the predetermined pattern with the image created from the reflected infrared radiation from the selected portion of the workpiece surface to the clarity of the predetermined pattern within an inspection standard image known to be indicative of the absence of alpha case.

Method for nondestructive/noncontact detection and quantification of

A method and apparatus for detecting a defect in a workpiece are disclosed. The workpiece is positioned with a surface of the workpiece to be inspected in an optical path of an infrared radiation detector. A selected portion of the workpiece is heated by scanning with electromagnetic radiation for a selected duration to cause an increase in radiance from any defect present in the selected portion. Any defects, present in the workpiece selected portion, which may cause a failure of the workpiece, may be detected and distinguished from minor surface anomalies by analyzing a transient response of the irradiance received by the infrared radiation detector.

Apparatus and method for detecting fatigue cracks using infrared

A method and apparatus for inspecting a channel through a workpiece or cooling holes through the surface of a gas turbine engine are disclosed. The gas turbine engine blade is mounted in a fixture such that a heated gas may be forced into the hollow interior of the blade during a heat-up cycle, and after a predetermined period of time, a solenoid valve switches to shut off the heated gas and to permit a chilled gas to be forced into the hollow interior of the blade for a cool-down cycle. An imaging infrared radiometer generates a series of images of the blade during both the heat-up and cool-down cycles. A selected group of parameters are determined from the series of images generated by the IR radiometer and defects within the cooling holes may then be detected by analyzing the parameters, such as a transient response of the infrared signature of the cooling holes during both the heat-up and the cool-down cycles.

Apparatus and method for inspecting cooling holes

In the present invention, a discrete region of the TBC is heated, as by applying a controlled quantity of laser energy onto the region for a time interval. Then, the radiant thermal energy of a region outside the laser strike region is measured at a predetermined time following the termination of the laser pulse. The intensity of this measured radiant energy is then compared with the radiant intensities which have been experimentally obtained from known thickness specimens and the thickness is inferred therefrom.

Coating thickness measurement

In the present invention, the temperatures of cooling passages in a gas turbine engine blade are changed, as by forcing a heated gas through them. The infrared signatures of the channels are measured during the initial temperature transient of the channels and the signatures are compared with a reference. The reference may be the signature of other channels on the same blade.

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Cincinnati, OH, United States of America

Thomas E Bantel