Book ChapterDOI
Ultrasonic Backscattering Measurements of Grain Size in Metal Alloys
Paul D. Panetta,Leslie G. Bland,Maureen Tracy,Waled Hassan +3 more
- pp 723-730
TLDR
In this article, an automated ultrasonic measurement tool which calculates grain size from ultrasonic backscattering measurement is presented. But this tool is limited to the case of metal alloys.Abstract:
Grain size is a key property that is carefully controlled during processing to create specific mechanical properties and reliability in final components. Achieving specific grain sizes is especially important in aircraft engines where temperatures can range from 260°C at the bore to 704°C at the rim, creating fatigue cracking in the bore and creep damage in the rim region. These competing failure mechanisms led to nickel alloy disks possessing fine-grains, ~5 microns in the bore and coarse-grains, ~80 micron in the rim. We created an automated ultrasonic measurement tool which calculates grain size from ultrasonic backscattering measurement. The tool unifies the entire process including controlling the ultrasonic scanner, data acquisition, experimental and theoretical backscattering calculations, numerical optimization to obtain grain size, and visualization. We tested our tool on IN718, Waspaloy, Rene 88 and Alloy 10. Our automated “Ultrasonic Metallography Tool” produced a map of the grain size where the color scale is the grain size. The authors believe this is the first time such a map has been generated automatically from ultrasonic backscattering measurements. Our results compare favorably with traditional metallography agreeing to within 2 microns for some alloys.read more
Citations
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Journal ArticleDOI
Non-destructive ultrasonic examination of root defects in friction stir welded butt-joints
TL;DR: In this article, a novel approach for the detection of root flaws is proposed using an immersion ultrasonic testing method in oblique incidence and backscatter mode, where the backscattered energy C-scan images obtained after an empirical positioning and proper time gating can be straightforwardly interpreted by direct comparison with typical "flaw" patterns, allowing for identification and localization of the root flaws in the weld.
Journal ArticleDOI
Grain size evaluation with time-frequency ultrasonic backscatter
TL;DR: In this paper, a joint time-frequency analysis is introduced into the ultrasonic backscatter model, with the independent scattering approximation, to evaluate the grain size of polycrystalline media.
Proceedings ArticleDOI
Techniques and software tools for estimating ultrasonic signal-to-noise ratios
TL;DR: In this article, the use of models to simulate ultrasonic inspections has played a key role in RD and (2) a Fortran-based engine for computing defect signal and backscattered grain noise characteristics.
Posted Content
Multiple scattering theory for polycrystalline materials with strong grain anisotropy: theoretical fundamentals and applications
TL;DR: In this paper, the dispersion and attenuation coefficient of high temperature titanium alloys with randomly oriented anisotropic crystallites is derived for ultrasonic non-destructive evaluation.
Journal ArticleDOI
Decomposition Method to Detect Fatigue Damage Precursors in Thin Components Through Nonlinear Ultrasonic With Collinear Mixing Contributions
Gheorghe Bunget,Stanley Henley,Chance Glass,James Rogers,Matthew R Webster,Kevin Farinholt,Fritz Friedersdorf,Marc Pepi,Anindya Ghoshal,Siddhant Datta,Aditi Chattopadhyay +10 more
TL;DR: In this article, the authors investigated the feasibility of incorporating collinear wave mixing interactions into second harmonic assessments to improve the sensitivity of the nonlinear parameter to a microstructural accumulation of damage precursors.
References
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Book
Fundamentals of Ultrasonic Nondestructive Evaluation: A Modeling Approach
TL;DR: In this article, the Fourier Transform and Dirac Delta Function are used to measure the properties of an ultrasonic NDE with models, and the Stationary Phase Method (SPM) is used to scale the model-based defect sizing.
Journal ArticleDOI
Estimating fatigue sensitivity to polycrystalline Ni‐base superalloy microstructures using a computational approach
TL;DR: In this article, a microstructure-sensitive crystal plasticity model is used to explicitly model individual grains and polycrystals, which is then used to explore effects of grain size distribution and secondary and tertiary coherent γ′ precipitate size distributions and volume fractions on the cyclic inelastic strain distribution.
Journal ArticleDOI
Processing, microstructure, and properties of β titanium alloys modified with boron
TL;DR: In this paper, the development of βTi alloys that are modified with small boron (B) additions to achieve enhanced elevated temperature capability is described. And the implications of B additions on the microstructural evolution and affordability of subsequent processing is also discussed.
Proceedings ArticleDOI
The effect of dual microstructure heat treatment on an advanced nickel-base disk alloy
TL;DR: In this paper, five heat treat options for an advanced nickel-base disk alloy, LSHR, have been investigated, including two conventional solution heat treat cycles, subsolvus/oil quench and supersolicus/fan cool, and three advanced dual microstructure heat treat (DMHT) options.
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