Measuring and testing – Vibration – Resonance – frequency – or amplitude study
Reexamination Certificate
1999-12-03
2002-06-25
Williams, Hezron (Department: 2856)
Measuring and testing
Vibration
Resonance, frequency, or amplitude study
Reexamination Certificate
active
06408695
ABSTRACT:
BACKGROUND OF THE INVENTION
The invention relates to titanium inspection methods and systems. In particular, the invention relates to methods and systems for inspecting titanium using ultrasonic energy in which the detection of flaws that may be critical to applications of the titanium material is enhanced.
Nondestructive evaluation by ultrasonic inspection and ultrasonic inspection testing is a known material testing and evaluation method. Ultrasonic testing typically requires that detectable flaws possess different acoustic behaviors from bulk material under similar ultrasonic inspection. This different behavior permits the ultrasonic inspection to detect flaws, grains, imperfections, and other related microstructural characteristics for a material. While conventional ultrasonic inspection methods and ultrasonic inspection testing may be adequate for detecting some flaws in titanium, these methods may be limited by noise generated in the ultrasonic inspection. For example, some ultrasonic inspection methods may mask or confuse generated noise with flaws, such as but not limited to large undesirable grains, colonies of undesirable titanium grains, and other microstructural characteristics in the titanium material that may limit applications for the titanium material.
Known ultrasonic inspection methods select an ultrasonic inspection frequency based on a flaw size alone. These ultrasonic inspection methods do not rely on the wavelength of the applied ultrasonic inspection energy to determine granular and microstructural characteristics of the material. The wavelength of the ultrasonic inspection energy is important for ultrasonic inspection, since a short wavelength will readily resolve small flaws in titanium materials, in which these small flaws may be flaws that are critical, in other word, flaws that limit the applications of titanium materials.
Thus, in order to determine acceptable titanium materials for certain critical applications, it is desirable to provide an ultrasonic inspection process that accurately determines the nature of noise during ultrasonic inspection. The ultrasonic inspection method should determine if ultrasonic inspection noise is attributed to a defect, such as a critical flaw, in the titanium material, due to noise, or due to other factors.
Therefore, a need exists for an ultrasonic inspection method for determining material characteristics and properties. Further, a need exists for an ultrasonic inspection method for determining processed titanium characteristics and properties and detecting flaws in titanium that may limit applications of the titanium. Furthermore, a need exists for determining material configurations and characteristics for accurate ultrasonic inspection methods that can minimize noise contributions to the ultrasonic inspection and enhance detection of small but “critical” flaws in titanium.
SUMMARY OF THE INVENTION
In one aspect of the invention, an ultrasonic inspection method is provided. The ultrasonic inspection method is capable of detecting critical flaws in the titanium material that may limit titanium material applications. The ultrasonic inspection method comprises fixing at least one of frequency or grain size of the titanium material as a constant for the ultrasonic inspecting; wherein the frequency that is fixed is representative of critical flaws in the titanium material, and the grain size that is fixed is representative of critical flaws in the titanium material; ultrasonic inspecting the titanium material in which the step of ultrasonic inspecting the titanium material generates scattering from microstructural characteristics and features of the titanium material; detecting generated scattering; characterizing the type of detected scattering; and determining if the titanium material comprises critical flaws based on the type of scattering. If the scattering comprises predominantly Rayleigh scattering, which means that the Rayleigh scattering comprises at least a majority of the scattering and dominates other types of scattering, that the step of determining determines that the titanium material comprises uniform-fine grain titanium, however, if the scattering comprises Rayleigh scattering and other types of scattering, the step of determining determines that the titanium material may comprise critical flaws that may limit applications of the titanium material.
In another aspect of the invention, a system for implementing an ultrasonic inspection method, as embodied by the invention is provided. The ultrasonic inspection system is capable of detecting critical flaws in the titanium material that may limit titanium material applications. The ultrasonic inspection system comprises means for fixing at least one of frequency or grain size of the titanium material as a constant for the ultrasonic inspecting; wherein the frequency that is fixed is representative of critical flaws in the titanium material, and the grain size that is fixed is representative of critical flaws in the titanium material; means for ultrasonic inspecting the titanium material in which the means for ultrasonic inspecting the titanium material generates scattering from microstructural characteristics and features of the titanium material; means for detecting generated scattering; means for characterizing the type of detected scattering; and means for determining if the titanium material comprises critical flaws based on the type of scattering. If the scattering comprises predominantly Rayleigh scattering, the means for determining determines that the titanium material comprises uniform-fine grain titanium. However, if the scattering comprises Rayleigh scattering and other types of scattering, the means for determining determines that the titanium material may comprise critical flaws that may limit applications of the titanium material.
These and other aspects, advantages and salient features of the invention will become apparent from the following detailed description, which, when taken in conjunction with the annexed drawings, where like parts are designated by like reference characters throughout the drawings, disclose embodiments of the invention.
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Bewlay Bernard Patrick
Deaton, Jr. John Broddus
Gigliotti, Jr. Michael Francis Xavier
Gilmore Robert Snee
Garber C D
General Electric Company
Johnson Noreen C.
Santandrea Robert P.
Williams Hezron
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