Surface Reactivity of Nanostructured Light Weight MetalsHenry J. Rack, Clemson University, DMR 0836068 This research is examining the hypothesis that the observed differences in surface reactivity of nanostructure and coarse grained titanium arise from differences in the structure and electrical characteristics of native surface oxide films formed above and at far field from grain boundaries. KPFM studies have shown that the surface potentialof coarse grained cp-Ti is affected by surface topography and substrate microstructure, with grain boundaries exhibiting a discrete potential drop, the level of this potential depending upon the grain boundary being examined. HRTEM studies of the near surface matrix/grain boundary and the native surface oxide atomic structure lying above each are presently under way to establish the connectivitybetween the surface potential measurements, the thickness/ atomic structure of surface oxide over the boundaries and matrix, and the grain boundary structure. Surface Potential Height a b c d A scratch is marked in height image by “BB´” which has a high potential marked by “BB´” in surface potential image. Potential drop at grain boundary is marked by “AA´” in the surface potential image while no trace of a grain boundary could be detected in height image.
Surface Reactivity of Nanostructured Light Weight MetalsHenry J. Rack, Clemson University, DMR 0836068 KPFM studies were conducted in the Nanocenter of the Department of Physics and Astronomy at the University of South Carolina under the supervision of Prof. S. Crittenden. Nanostructure titanium has been processed in collaboration with Dr. Terry Lowe, Chief Technical Officer, Manhattan Scientifics, Santa Fe, NM, Prof. Ruslan Valiev, Ufa State Aviation Technical University, Ufa, Russia andProf. Yuri Estrin, Monash University, Clayton, Victoria, Australia. The PI presented lectures at the Charles University (Prague, CZ) and the Applied Science University at Giessen-Friedberg, Germany on “Surface Reactivity of Titanium” on May 27 and June 4, 2010, respectively. One undergraduate student, Mr. James Marro has been trained and is assisting Mr. Samiee in the preparation of various samples for experimental studies. Enhanced adhesion of mice fibroblast cells L929 after 24 hrs; conventional coarse grain (a) and nanostructure (b) cp grade 4 Titanium  . a b