Date of Award
Master of Science
Materials Science and Engineering
A prototype method was developed utilizing recent advances in x-ray microfocus radiography and image processing to study the effects of ceramic tape casting variables on microstructure development. The system was designed to incorporate several advantages over traditional, ceramic characterization routes: (i) the system functions as an area detector (rather than a conventional point- or line-detector) providing rapid, statistical information on inhomogeneities in tape microstructures; (ii) it is capable of detecting small pores and surface pits on the order of 10 microns in size; (iii) it can also detect tape thickness variations on the order of 10 microns; (iv) it is capable of tracking these heterogeneities as a function of time and position throughout casting, debinding, and sintering; and (v) using standard equipment, it is amenable to scale up for quantitative process control and monitoring in an industrial setting. The prototype involved magnification radiography using a microfocus x-ray generator, digitization of the radiographs using a 14-bit CCD camera, and image processing of the digitized radiographs. Key parameters affecting image resolution were analyzed including: magnification, the presence or absence of fum cassettes, variations in film type, and the x-ray energy. The system was benchmarked in a study of the effects of particle size, tape thickness, and sintering temperature of alumina tapes. Optical and scanning electron microscopy were also performed to confirm the results of the radiography data.
Digital Repository @ Iowa State University, http://lib.dr.iastate.edu
Clay Wesley Maranville
Maranville, Clay W., "Radiographic imaging of microstructural defects in ceramic tapes" (1996). Retrospective Theses and Dissertations. 242.