@article{chan_stoner_thompson_scattergood_piascik_2013, title={Fracture toughness improvements of dental ceramic through use of yttria-stabilized zirconia (YSZ) thin-film coatings}, volume={29}, ISSN={["1879-0097"]}, DOI={10.1016/j.dental.2013.05.003}, abstractNote={The aim of this study was to evaluate strengthening mechanisms of yttria-stabilized zirconia (YSZ) thin film coatings as a viable method for improving fracture toughness of all-ceramic dental restorations.Bars (2mm×2mm×15mm, n=12) were cut from porcelain (ProCAD, Ivoclar-Vivadent) blocks and wet-polished through 1200-grit using SiC abrasive. A Vickers indenter was used to induce flaws with controlled size and geometry. Depositions were performed via radio frequency magnetron sputtering (5mT, 25°C, 30:1 Ar/O2 gas ratio) with varying powers of substrate bias. Film and flaw properties were characterized by optical microscopy, scanning electron microscopy (SEM), and X-ray diffraction (XRD). Flexural strength was determined by three-point bending. Fracture toughness values were calculated from flaw size and fracture strength.Data show improvements in fracture strength of up to 57% over unmodified specimens. XRD analysis shows that films deposited with higher substrate bias displayed a high %monoclinic volume fraction (19%) compared to non-biased deposited films (87%), and resulted in increased film stresses and modified YSZ microstructures. SEM analysis shows critical flaw sizes of 67±1μm leading to fracture toughness improvements of 55% over unmodified specimens.Data support surface modification of dental ceramics with YSZ thin film coatings to improve fracture toughness. Increase in construct strength was attributed to increase in compressive film stresses and modified YSZ thin film microstructures. It is believed that this surface modification may lead to significant improvements and overall reliability of all-ceramic dental restorations.}, number={8}, journal={DENTAL MATERIALS}, author={Chan, Ryan N. and Stoner, Brian R. and Thompson, Jeffrey Y. and Scattergood, Ronald O. and Piascik, Jeffrey R.}, year={2013}, month={Aug}, pages={881–887} }
 @article{darling_chan_wong_semones_scattergood_koch_2008, title={Grain-size stabilization in nanocrystalline FeZr alloys}, volume={59}, ISSN={["1359-6462"]}, DOI={10.1016/j.scriptamat.2008.04.045}, abstractNote={Nanocrystalline Fe–Zr alloys with a nominal grain size of 10 nm were synthesized by mechanical alloying. The grain size in pure Fe was >200 nm after annealing for 1 h at T/TM = 0.5. Additions of 1 at.% Zr stabilized the grain size at 50 nm up to T/TM = 0.92. Particle pinning, solute drag and reduction in grain-boundary energy have been proposed as stabilization mechanisms. The stabilization in Fe–Zr alloys is attributed to a reduction in grain-boundary energy due to Zr segregation.}, number={5}, journal={SCRIPTA MATERIALIA}, author={Darling, Kris A. and Chan, Ryan N. and Wong, Patrick Z. and Semones, Jonathan E. and Scattergood, Ronald O. and Koch, Carl C.}, year={2008}, month={Sep}, pages={530–533} }
 @article{darling_guduru_reynolds_bhosle_chan_scattergood_koch_narayan_aboelfotoh_2008, title={Thermal stability, mechanical and electrical properties of nanocrystalline Cu3Ge}, volume={16}, ISSN={0966-9795}, url={http://dx.doi.org/10.1016/j.intermet.2007.11.005}, DOI={10.1016/j.intermet.2007.11.005}, abstractNote={The intermetallic ɛ1 compound Cu3Ge was produced through a mechanical alloying procedure that enables the formation of a nanograined microstructure. There is a dependence of grain size (20–11 nm) on milling conditions. The microstructure remained very stable even at temperatures up to 500 °C for 5 h which is a minimum of 76% of the melting temperature. The materials produced by these methods were in the form of powders with particle size ranging from 200 nm to 10 μm. The morphology of the particles varied with the largest being rough and irregular and the smallest being spherical. Preliminary resistivity measurements showed low resistivity, 8.8 μΩ cm, which is comparable to that previously reported for thin films with grain sizes thousands of times larger. Nanoindentation was also performed, yielding an elastic modulus of ∼110 GPa.}, number={3}, journal={Intermetallics}, publisher={Elsevier BV}, author={Darling, Kris A. and Guduru, R.K. and Reynolds, C. Lewis, Jr and Bhosle, Vikram M. and Chan, Ryan N. and Scattergood, Ronald O. and Koch, Carl C. and Narayan, J. and Aboelfotoh, M.O.}, year={2008}, month={Mar}, pages={378–383} }