Skip to Main Content
 

Global Search Box

 
 
 
 

Files

File List


36436.pdf (3.68 MB)

ETD Abstract Container

Abstract Header

Hall Impedance and Eddy Current Spectroscopy for Nondestructive Evaluation of Shot-Peened Ti-6Al-4V

Bodine, Nathanael M
http://orcid.org/0000-0003-1246-7508
http://rave.ohiolink.edu/etdc/view?acc_num=ucin1573572135697661

Abstract Details

2019, MS, University of Cincinnati, Engineering and Applied Science: Aerospace Engineering.
There is a growing need to determine the residual stress profiles in surface-treated components to accurately and reliably determine the remaining service life of the component and to reduce the risk of failure. To acquire depth-dependent residual stress profiles, the XRD technique requires multiple layers of material to be removed with electro-etching, which renders the tested component unsuitable for service use. The nondestructive evaluation community has been in search of a method that can determine the residual stress profiles in surface-treated aerospace engine alloy components nondestructively. A promising nondestructive technique using high-frequency eddy current spectroscopy has been investigated with much potential. However, the two principal effects of shot peening, namely residual stress and cold work, are opposite in sign in Ti-6Al-4V, resulting in almost complete cancellation between the two competing effects, causing the eddy spectroscopy technique to be incapable of determining the residual stress profile of shot-peened components. This study investigates an alternative electromagnetic residual stress profiling technique using a dual-mode inspection with Hall impedance and eddy current spectroscopy to separate the components of shot-peening. The effect of residual stress (elastic strain) and cold work (plastic strain) will be investigated on Ti-6Al-4V (36 HRC) using both Hall coefficient and eddy current techniques. Experimental results, relative Hall impedance and AECC change spectra, were 3 obtained on shot-peened Ti-6Al-4V (36 HRC) with Almen intensities of 4A, 8A, and 12A. Destructive XRD residual stress and cold work depth profiles were obtained from the literature on shot-peened Ti-6Al-4V (32 HRC) with Almen intensities of 4A, 8A, and 12A for comparison. Relative Hall coefficient and electric conductivity depth profiles were calculated from the XRD residual stress and cold work depth profiles on the shot-peened specimens, using electromagnetic and galvanomagnetic gauge factors that were obtained experimentally. Relative Hall impedance and AECC spectrums were simulated, which are used for comparison purposes. Next, the simulated relative Hall impedance and AECC change profiles of Ti-6Al-4V (32 HRC) were compared to experimental relative Hall impedance and AECC change profiles of shot-peened Ti-6Al-4V (36 HRC). It was found that the simulated relative Hall impedance change profiles are capable of predicting the general trend caused by shot-peening, but are unable to predict the magnitude of change. The simulated relative AECC change profiles are capable of predicting the trend caused by shot-peening and the magnitude of change fairly well in comparison to the relative Hall impedance relative change. In this study, the separation of the two competing effects caused by shot-peening was concluded to be not feasible at this time. Although the separation is currently not possible, the study shows evidence illustrating the possibility of separating the residual stress and cold work using the dual-mode inspection technique with Hall impedance and eddy current spectroscopy with further efforts. Empirical calibrations will need to be completed to obtain accurate galvanomagnetic and electromagnetic gauge factors that extend over a range of residual 4 stress and cold work levels that are comparable with the values in common shot-peened components.
Peter Nagy, Ph.D. (Committee Chair)
Yao Fu, Ph.D. (Committee Member)
Francesco Simonetti, Ph.D. (Committee Member)
115 p.
Aerospace Materials
residual stress assessment; Hall coefficient; eddy current; nondestructive evaluation

Recommended Citations

Citations

  • Bodine, N. M. (2019). Hall Impedance and Eddy Current Spectroscopy for Nondestructive Evaluation of Shot-Peened Ti-6Al-4V [Master's thesis, University of Cincinnati]. OhioLINK Electronic Theses and Dissertations Center. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1573572135697661

    APA Style (7th edition)

  • Bodine, Nathanael. Hall Impedance and Eddy Current Spectroscopy for Nondestructive Evaluation of Shot-Peened Ti-6Al-4V. 2019. University of Cincinnati, Master's thesis. OhioLINK Electronic Theses and Dissertations Center, http://rave.ohiolink.edu/etdc/view?acc_num=ucin1573572135697661.

    MLA Style (8th edition)

  • Bodine, Nathanael. "Hall Impedance and Eddy Current Spectroscopy for Nondestructive Evaluation of Shot-Peened Ti-6Al-4V." Master's thesis, University of Cincinnati, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin1573572135697661

    Chicago Manual of Style (17th edition)

ucin1573572135697661
290
© 2019, all rights reserved.
This open access ETD is published by University of Cincinnati and OhioLINK.