Ivar E. Reimanis
Herman F. Coors Distinguished Professor of
Ceramic Engineering, Colorado School of Mines
Director, Colorado Center for Advanced Ceramics
Professor, Metallurgical and Materials Engineering
12 PM, Friday, April 14th, 2017
1003 Kemper Hall
Abstract: The title of this talk appears to be an oxymoron: most toughening mechanisms in ceramics require the presence of a second phase that leads to visible light scattering due to index of refraction mismatch. However, it is possible to stimulate toughening while retaining transparency if the second phase displays the same index of refraction as the matrix, or if the second phase particle size is significantly smaller than the wavelength of light. This talk explores the possibility to create nanostructures in magnesium aluminate spinel, a classic transparent ceramic armor and window material, via two techniques. The first is by the precipitation of alumina in single-phase alumina-rich spinel. The second is by the partial dissolution of alumina in composites of stoichiometric spinel and alumina. It is shown that significant toughening may be achieved by these techniques and that they provide a route by which to create tough transparent spinel.
Biography: Ivar Reimanis is the Herman F. Coors Distinguished Professor of Ceramic Engineering in the Metallurgical and Materials Engineering Department at Colorado School of Mines in Golden, Colorado. He serves as Director of the Colorado Center for Advanced Ceramics and recently served as interim Department for two years. Dr. Reimanis earned a BS in Materials Science and Engineering at Cornell University in 1984, a MS in Materials Science and Mineral Engineering at University of California, Berkeley, and a PhD in Materials at the University of California, Santa Barbara in 1990. He spent a year under a Max Planck Institute postdoctoral fellowship in Stuttgart, Germany. Dr. Reimanis worked as a postdoc at Los Alamos National Laboratory after which he served as a technical staff member until 1994 when he joined the Colorado School of Mines. He spent a sabbatical at the University of Western Australia in Perth in 2002 as a Gledden Visiting Senior Fellow and was awarded a United States Fulbright award in 2007 to spend a semester at the Indian Institute of Science in Bangalore. Dr. Reimais is a Fellow of the American Ceramic Society, and he has served on ACerS Board of Directors and has volunteered in several other roles within ACerS. Dr. Reimanis has authored or co-authored 110 refereed papers and five patents.