Accession Number:

ADA595876

Title:

Characterization of Microstructure with Low Frequency Electromagnetic Techniques (Preprint)

Descriptive Note:

Final rept. 25 Jun 2009-25 Jan 2014

Corporate Author:

AIR FORCE RESEARCH LAB WRIGHT-PATTERSON AFB OH MATERIALS AND MANUFACTURING DIRECTORATE

Personal Author(s):

• Pilchak, Adam L.
• Blodgett, Mark P.
• Cherry, Matthew R.
• Sathish, Shamachary
• Cherry, Aaron J.

Report Date:

2014-02-01

Pagination or Media Count:

11.0

Abstract:

A new computational method for characterizing the relationship between surface crystallography and electrical conductivity in anisotropic materials with low frequency electromagnetic techniques is presented. The method is discussed from the standpoint of characterizing the orientation of a single grain, as well as characterizing statistical information about grain ensembles in the microstructure. Large-area electron backscatter diffraction EBSD data was obtained and used in conjunction with a synthetic aperture approach to simulate the eddy current response of beta annealed Ti-6Al-4V. Experimental eddy current results are compared to the computed eddy current approximations based on electron backscatter diffraction EBSD data, demonstrating good agreement. The detectability of notches in the presence of noise from microstructure is analyzed with the described simulation method and advantages and limitations of this method are discussed relative to other NDE techniques for such analysis.

Descriptors:

• *CRYSTALLOGRAPHY
• *EDDY CURRENTS
• *ELECTRICAL CONDUCTIVITY
• *ELECTROMAGNETISM
• *LOW FREQUENCY
• *MICROSTRUCTURE
• ANISOTROPY
• APPROXIMATION(MATHEMATICS)
• BACKSCATTERING
• DIFFRACTION
• GRAIN SIZE
• ORIENTATION(DIRECTION)

Subject Categories:

• Crystallography
• Electricity and Magnetism

Distribution Statement:

APPROVED FOR PUBLIC RELEASE