Development of Textured Microstructures in Ceramics with Large Thermal Expansion Anisotropy
Fe_2TiO_5 exhibits a high degree of anisotropy in both thermal expansion and paramagnetic susceptibility. Anisotropy in paramagnetic susceptibility allows textured microstructures to be produced using magnetically-assisted grain alignment during sample fabrication. The resulting solid-state sintered aligned samples had a b-axis orientation coefficient of 3.33 (vs 6.60 for an aligned powder–epoxy suspension) where an orientation coefficient of 1 represents a randomly-oriented sample. This texturing reduced the residual stresses generated from the large thermal expansion anisotropy of the control samples, as evidenced by reduced microcracking and morphological texturing of the aligned microstructure.
© 1994 The American Ceramic Society. Manuscript No. 194613. Received May 3, 1993; approved September 24, 1993. Support for this work was provided by the National Science Foundation under Grant No. DMR-9023629. We would like to thank Prof. Heinrich Jaeger of the University of Chicago for the use of his magnet and Terry Morkved for his assistance in its operation.