Mean grain size estimation for copper-alloy samples based on attenuation coefficient estimates

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Mean grain size estimation for copper-alloy samples based on attenuation coefficient estimates

Please use this identifier to cite or link to this item: http://hdl.handle.net/10355/14579

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dc.contributor.advisor Neal, Steven P. en_US
dc.contributor.author Wagner, John William
dc.date.accessioned 2012-06-08T16:08:49Z
dc.date.available 2012-06-08T16:08:49Z
dc.date.issued 2011
dc.date.submitted 2011 Fall en_US
dc.identifier.other WagnerJ-120811-T445
dc.identifier.uri http://hdl.handle.net/10355/14579
dc.description Title from PDF of title page (University of Missouri--Columbia, viewed on June 8, 2012). en_US
dc.description The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. en_US
dc.description Thesis advisor: Dr. Steven P. Neal en_US
dc.description Includes bibliographical references. en_US
dc.description M. S. University of Missouri--Columbia 2011. en_US
dc.description Dissertations, Academic -- University of Missouri--Columbia -- Mechanical and aerospace engineering. en_US
dc.description "December 2011" en_US
dc.description.abstract A polycrystalline metal's grain size affects its mechanical properties; therefore, the ability to effectively and easily monitor grain size during a manufacturing process is critical. Conventional destructive tests utilized for estimating grain size or mechanical properties are expensive and time consuming. Past research has shown some success in nondestructively estimating a metal's mean grain size using attenuation coefficient measurements acquired from ultrasound. Within this research, a water immersion, pulse-echo mode of ultrasonic testing is employed to estimate the mean grain diameter of 5 thin copper-alloy samples using attenuation coefficient measurements. The attenuation coefficients were estimated via spectral analysis of interface reflections. The interface reflections were corrected for reflection and transmission effects, beam field diffraction, and water attenuation effects. An experimental diffraction correction approach and an inverse water attenuation filter accounted for diffraction and water attenuation, respectively. A Leave-One-Out (LOO) cross-validation algorithm was implemented to generate correlation models needed for grain diameter estimation. Models were developed as a function of ultrasonic wavelength and yielded grain diameter estimates for each sample. Estimates were seen to compare favorably with the stated grain diameters of the copper-alloy samples. en_US
dc.format.extent vii, 73 pages en_US
dc.language.iso en_US en_US
dc.publisher University of Missouri--Columbia en_US
dc.relation.ispartof 2011 Freely available theses (MU) en_US
dc.subject attenuation coefficient en_US
dc.subject non-destructive evaluation en_US
dc.subject signal processing en_US
dc.subject polycrystalline metal en_US
dc.title Mean grain size estimation for copper-alloy samples based on attenuation coefficient estimates en_US
dc.type Thesis en_US
thesis.degree.discipline Mechanical and aerospace engineering en_US
thesis.degree.grantor University of Missouri--Columbia en_US
thesis.degree.name M.S. en_US
thesis.degree.level Masters en_US
dc.relation.ispartofcommunity University of Missouri-Columbia. Graduate School. Theses and Dissertations. Theses. 2011 Theses


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