@article{frigola_harrysson_horn_west_aman_rigsbee_ramirez_murr_medina_wicker_et al._2014, title={Fabricating copper components with electron beam melting}, volume={172}, number={7}, journal={Advanced Materials & Processes}, author={Frigola, P. and Harrysson, O. A. and Horn, T. J. and West, H. A. and Aman, R. L. and Rigsbee, J. M. and Ramirez, D. A. and Murr, L. E. and Medina, F. and Wicker, R. B. and et al.}, year={2014}, pages={20–24} } @article{piyawit_xu_mathaudhu_freudenberger_rigsbee_zhu_2014, title={Nucleation and growth mechanism of Ag precipitates in a CuAgZr alloy}, volume={610}, ISSN={["1873-4936"]}, DOI={10.1016/j.msea.2014.05.023}, abstractNote={CuAgZr alloy is a variant of the CuAg alloy that is developed for high strength and high conductivity applications. Its strengthening is accomplished mainly by the precipitation of Ag precipitates, which tend to align on {111} planes in the Cu matrix. This alignment has been reported to be caused by stacking faults on {111} planes. Contrary to these reports, this research presents evidence for Ag precipitates formation on {111} planes due to the minimization of elastic energy. The Ag precipitates were formed by clustering of Ag atoms while maintaining the fcc crystal structure of the matrix. They have faceted {111} interfaces with the matrix. The thickening of precipitates appears to be by the ledge growth mechanism, which is resulted in by misfit dislocation networks on the interface.}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Piyawit, W. and Xu, W. Z. and Mathaudhu, S. N. and Freudenberger, J. and Rigsbee, J. M. and Zhu, Y. T.}, year={2014}, month={Jul}, pages={85–90} } @article{maheshwari_stevie_myneni_ciovati_rigsbee_dhakal_griffis_2014, title={SIMS analysis of high-performance accelerator niobium}, volume={46}, ISSN={["1096-9918"]}, DOI={10.1002/sia.5461}, abstractNote={Niobium is used to fabricate superconducting radio frequency accelerator modules because of its high critical temperature, high critical magnetic field, and easy formability. Recent experiments have shown a very significant improvement in performance (over 100%) after a high-temperature bake at 1400 °C for 3 h. SIMS analysis of this material showed the oxygen profile was significantly deeper than the native oxide with a shape that is indicative of diffusion. Positive secondary ion mass spectra showed the presence of Ti with a depth profile similar to that of O. It is suspected that Ti is associated with the performance improvement. The source of Ti contamination in the anneal furnace has been identified, and a new furnace was constructed without Ti. Initial results from the new furnace do not show the yield improvement. Further analyses should determine the relationship of Ti to cavity performance. Copyright © 2014 John Wiley & Sons, Ltd.}, journal={SURFACE AND INTERFACE ANALYSIS}, author={Maheshwari, P. and Stevie, F. A. and Myneni, G. R. and Ciovati, G. and Rigsbee, J. M. and Dhakal, P. and Griffis, D. P.}, year={2014}, month={Nov}, pages={288–290} } @article{maheshwari_tian_reece_kelley_myneni_stevie_rigsbee_batchelor_griffis_2011, title={Surface analysis of Nb materials for SRF cavities}, volume={43}, ISSN={["1096-9918"]}, DOI={10.1002/sia.3513}, abstractNote={Superconducting Radio Frequency (SRF) cavities provide enhanced efficiency and reduced energy consumption in present-day particle accelerators. Niobium is the material of choice for SRF cavities due to its high critical temperature and critical magnetic field. In order to understand why certain treatments, especially a low temperature bake, improve performance, it is important to study Nb surface characteristics and identify elemental contaminants which may affect the performance of the cavity.[1] Initial studies using SIMS and Focused Ion Beam (FIB) prepared specimens for Transmission Electron Microscopy (TEM) have helped to characterize the Nb surface and measure the surface oxide layer thickness.[2] C, N and O are of particular interest as interstitial contaminants and earlier studies suggested very high H concentration. In the present study, ion implants of C, N, O and deuterium (D) in Nb and Si were analyzed using SIMS. D was implanted to characterize H while avoiding interference from the high H background. The D implant was easily detectable in Si, but showed a constant value and no implant shape in Nb. This result implies either that D (and by implication, hydrogen) has a high mobility in Nb, or that there is movement of D due to the primary ion beam. Nevertheless, C, N, and O could be quantified using the ion implants. Depth profiles of polycrystalline and single crystal Nb samples were also obtained. While both types of Nb samples contained low C concentration, the single crystal Nb samples showed higher N and O content. Copyright © 2010 John Wiley & Sons, Ltd.}, number={1-2}, journal={SURFACE AND INTERFACE ANALYSIS}, author={Maheshwari, P. and Tian, H. and Reece, C. E. and Kelley, M. J. and Myneni, G. R. and Stevie, F. A. and Rigsbee, J. M. and Batchelor, A. D. and Griffis, D. P.}, year={2011}, pages={151–153} } @article{zhang_kostorz_liu_rigsbee_suryanarayana_wang_zhu_zhang_2008, title={Mechanical Behavior of Nanostructured Materials, in Honor of Carl Koch held at TMS 2007, Orlando, Florida Preface}, volume={493}, ISSN={["0921-5093"]}, DOI={10.1016/j.msea.2008.01.019}, number={1-2}, journal={MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING}, author={Zhang, Xinghang and Kostorz, Gernot and Liu, Chain T. and Rigsbee, Mike and Suryanarayana, C. and Wang, Haiyan and Zhu, Yuntian and Zhang, Deliang}, year={2008}, month={Oct}, pages={1–2} } @article{zhang_zhu_rigsbee_suryanarayana_wang_liu_2007, title={Mechanical Behavior of nanostructured materials symposium honoring Carl Koch}, volume={59}, ISSN={["1047-4838"]}, DOI={10.1007/s11837-007-0116-2}, number={9}, journal={JOM}, author={Zhang, Xinghang and Zhu, Yuntian and Rigsbee, Mike and Suryanarayana, C. and Wang, Haiyan and Liu, C. T.}, year={2007}, month={Sep}, pages={49–49} } @article{narayan_bhaduri_fischman_rigsbee_zhang_2007, title={Next generation biomaterials - Preface}, volume={27}, ISSN={["0928-4931"]}, DOI={10.1016/j.msec.2006.05.022}, number={3}, journal={MATERIALS SCIENCE & ENGINEERING C-BIOMIMETIC AND SUPRAMOLECULAR SYSTEMS}, author={Narayan, Roger J. and Bhaduri, Sarit B. and Fischman, Gary and Rigsbee, J. Michael and Zhang, Xinghang}, year={2007}, month={Apr}, pages={345–346} } @article{aaronson_rigsbee_muddle_nie_2002, title={Aspects of the surface relief definition of bainite}, volume={47}, ISSN={["1359-6462"]}, DOI={10.1016/S1359-6462(02)00130-6}, abstractNote={Abstract Criticisms of reports that ferrite laths have a sessile interfacial structure are refuted. A local lattice correspondence, achieved across coherent regions between interfacial defects, suffices to produce surface reliefs and martensitic crystallography [Prog. Mater. Sci. 42 (1997) 101]. However, formation of tent-shaped surface reliefs by monocrystalline laths/plates is inconsistent with martensitic growth.}, number={3}, journal={SCRIPTA MATERIALIA}, author={Aaronson, HI and Rigsbee, JM and Muddle, BC and Nie, JF}, year={2002}, month={Aug}, pages={207–212} } @article{haman_scripa_rigsbee_lucas_2002, title={Production of thin calcium phosphate coatings from glass source materials}, volume={13}, ISSN={["1573-4838"]}, DOI={10.1023/A:1013882029896}, number={2}, journal={JOURNAL OF MATERIALS SCIENCE-MATERIALS IN MEDICINE}, author={Haman, JD and Scripa, RN and Rigsbee, JM and Lucas, LC}, year={2002}, month={Feb}, pages={175–184} } @article{ji_rigsbee_2001, title={Growth of highly textured yttria-stabilized zirconia thin film by reactive magnetron sputtering}, volume={20}, ISSN={["0261-8028"]}, DOI={10.1023/A:1010961115476}, number={7}, journal={JOURNAL OF MATERIALS SCIENCE LETTERS}, author={Ji, Z and Rigsbee, JM}, year={2001}, pages={611–613} } @article{ji_rigsbee_2001, title={Growth of tetragonal zirconia coatings by reactive sputter deposition}, volume={84}, ISSN={["0002-7820"]}, DOI={10.1111/j.1151-2916.2001.tb01102.x}, abstractNote={Zirconia coatings were produced by reactive dc magnetron sputter deposition, using a system with multiple sputter sources and a biased substrate stage. Tetragonal zirconia with either a random orientation or a highly (111) preferred orientation was formed by applying a substrate bias. Coating grown with no substrate bias had the equilibrium monoclinic structure. X-ray diffraction and transmission electron microscopy analyses revealed that bias sputtering could effectively decrease crystalline size in the as-deposited coating, which resulted in room-temperature stabilization of the tetragonal phase. The fraction of tetragonal phase, the desired phase for transformation-toughening behavior, was strongly dependent on the substrate bias and post-deposition annealing temperature.}, number={12}, journal={JOURNAL OF THE AMERICAN CERAMIC SOCIETY}, author={Ji, ZQ and Rigsbee, JM}, year={2001}, month={Dec}, pages={2841–2844} } @article{burke_haman_weimer_cheney_rigsbee_lucas_2001, title={Influence of coating strain on calcium phosphate thin-film dissolution}, volume={57}, ISSN={["0021-9304"]}, DOI={10.1002/1097-4636(200110)57:1<41::AID-JBM1139>3.0.CO;2-9}, abstractNote={The success of calcium phosphate (CaP) coatings used to accelerate initial bone growth onto dental implants can vary depending on the CaP phases present in the coating. In this study, the effect of CaP coating crystal structure and morphology on dissolution rates was investigated. RF magnetron-sputtered CaP coatings (NTC) were compared to a less strained coating (HTC) obtained from heat treatment of sputtered samples at 550°C. Coating strain differences were apparent in XRD spectra where hydroxyapatite-like planes shifted by 0.5° 2θ and 0.05° 2θ for the NTC and HTC coatings, respectively. HTC XRD peak widths were broader than NTC peak widths, indicating smaller crystals or grain sizes. These differences in grain size were corroborated by imaging with scanning probe microscopy. NTC coatings dissolved at a 300% faster rate than HTC coatings. A major factor contributing to this kinetic effect was the level of strain in both coatings. These results suggest an alternate design for CaP coatings can be obtained through the manipulation of coating strain. Using this approach, delivery of different ionic gradients from CaP coatings to surrounding tissue environments can be obtained from surfaces having similar chemistries. © 2001 John Wiley & Sons, Inc. J Biomed Mater Res 57: 41–47, 2001}, number={1}, journal={JOURNAL OF BIOMEDICAL MATERIALS RESEARCH}, author={Burke, EM and Haman, JD and Weimer, JJ and Cheney, AB and Rigsbee, JM and Lucas, LC}, year={2001}, month={Oct}, pages={41–47} } @article{ji_haynes_ferber_rigsbee_2001, title={Metastable tetragonal zirconia formation and transformation in reactively sputter deposited zirconia coatings}, volume={135}, ISSN={["0257-8972"]}, DOI={10.1016/S0257-8972(00)00910-5}, abstractNote={Zirconia coatings were produced by reactive d.c. magnetron sputter deposition using a system with multiple sputter sources and a biased substrate stage. Crystal structure and phase stability of the coatings were investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Tetragonal zirconia with either a random orientation or a highly (111) preferred orientation was deposited when a substrate bias was applied, whereas coatings grown with no substrate bias had the equilibrium monoclinic structure. It was revealed that bias sputtering effectively decreased crystallite size in the as-deposited coatings, which resulted in room temperature stabilization of the metastable tetragonal phase. XRD analysis of annealed coatings showed that the volume fraction and stability of the tetragonal phase was strongly dependent on substrate bias and annealing temperature.}, number={2-3}, journal={SURFACE & COATINGS TECHNOLOGY}, author={Ji, Z and Haynes, JA and Ferber, MK and Rigsbee, JM}, year={2001}, month={Jan}, pages={109–117} } @article{ji_haynes_voelkl_rigsbee_2001, title={Phase formation and stability in reactively sputter deposited yttria-stabilized zirconia coatings}, volume={84}, ISSN={["1551-2916"]}, DOI={10.1111/j.1151-2916.2001.tb00770.x}, abstractNote={Yttria-stabilized zirconia (YSZ) coatings were produced by reactively cosputtering metallic zirconium and yttrium targets in an argon and oxygen plasma using a system with multiple magnetron sputtering sources. Coating crystal structure and phase stability, as functions of Y2O3 content, substrate bias, and annealing temperature, were investigated by X-ray diffraction (XRD) and transmission electron microscopy (TEM). Results demonstrated that highly (111)-oriented tetragonal and cubic zirconia structures were formed in 2 and 4.5 mol% Y2O3 coatings, respectively, when the coatings were grown with an applied substrate bias. Conversely, coatings deposited with no substrate bias had random tetragonal and cubic structures. XRD analysis of annealed coatings showed that the cubic zirconia in 4.5 mol% Y2O3 coatings exhibited structural stability at temperatures up to 1200°C. Transformation of the tetragonal to monoclinic phase occurred in 2 mol% Y2O3 coating during high-temperature annealing, with the fraction of transformation dependent on bias potential and annealing temperature.}, number={5}, journal={JOURNAL OF THE AMERICAN CERAMIC SOCIETY}, author={Ji, ZQ and Haynes, JA and Voelkl, E and Rigsbee, JM}, year={2001}, month={May}, pages={929–936} }