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Thomas W. Scharf

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Thomas W. Scharf Dr. Thomas W. Scharf Professor Department of Materials Science and Engineering University of North Texas P.O. BOX 305310 Denton, TX 76203-5310 (940) 891-6837 e-mail: [email protected] EDUCATION B.S. Ceramic Science and Engineering, The Pennsylvania State University, University Park, PA, 1994. Thesis title, “The Effects of Oxidation on the Strength Behavior of SiC Fibers” under Dr. Richard E. Tressler. M.S. Metallurgical and Materials Engineering, The University of Alabama, Tuscaloosa, AL, 1997. Thesis title, “Structural, Tribo-Mechanical, and Thermal Characterization of Sputtered Diamond-Like Carbon and Nitrogenated Diamond-Like Carbon Thin Films” under Dr. John A. Barnard. Ph.D. Metallurgical and Materials Engineering, The University of Alabama, Tuscaloosa, AL, 2000. Dissertation title, “Growth, Structure, and Mechanical Wear Strength of Ultra-Thin Ion Beam and Sputter Deposited Hard Coatings” under Dr. John A. Barnard. PROFESSIONAL EXPERIENCE 5/14-present: Professor, Department of Materials Science and Engineering, University of North Texas, Denton, TX. 5/10-5/14: Associate Professor, Department of Materials Science and Engineering, University of North Texas, Denton, TX. 9/05-5/10: Assistant Professor, Department of Materials Science and Engineering, University of North Texas, Denton, TX. •Established a materials tribology laboratory to measure friction, wear and lubrication processes by in situ and ex situ methods. •Constructed a viscous flow atomic layer/chemical vapor deposition reactor to synthesize solid lubricant and wear resistant coatings for moving mechanical assembly applications. •Secured several external federal grants (listed under current funding). •Developed two new courses: Bonding, Structure and Crystallography and Tribology of Materials. 6/06-8/06; 7/07-8/07; 7/09-9/09; 6/11-7/11, 7/12-8/12, 6/13-8/13 & 6/14-8/14: University Summer Faculty, Microsystems Materials, Tribology, & Technology (2006 & 12007) , Multiscale Metallurgical Science & Technology (2009, 2011 & 2012), and Materials Aging and Reliability Departments (2013 & 2014), Sandia National Laboratories, Albuquerque, NM. •Investigated solid lubrication mechanisms in diamond-like carbon, lubricious oxides and MoS2/Sb2O3/Au nanocomposite coatings for applications in moving mechanical assemblies, such as weapon system components, microsystems, and space (satellite) components. •Studied high temperature wear behavior and mechanisms of Tantalum- and Cobalt-based alloys. 6/03-9/05: Limited Term Member of the Technical Staff, Microsystems Materials, Tribology, and Technology, Sandia National Laboratories, Albuquerque, NM. •Co-developed a new process for the deposition of crystalline tungsten disulphide (WS2) solid lubricant coatings with monolayer precision by atomic layer deposition (ALD) for potential applications in moving mechanical assemblies such as MEMS (SMM and LIGA) and rolling element bearings. •Investigated the coverage, friction, and wear behavior of PECVD diamond-like carbon (DLC) and diamond-like nanocomposite (DLN) coatings for potential applications in low mass mechanisms and LIGA technology. •Characterized the self-mated tribology of ultrananocrystalline diamond (UNCD) thin films for potential applications to MEMS resonators. 6/00-6/03: Postdoctoral Research Associate, Tribology Section, Naval Research Laboratory, Washington, D.C. •Investigated the friction and wear life under dry sliding of amorphous diamond-like carbon (DLC) coatings using the NRL homebuilt in situ Raman tribometer. •Developed a model for quantifying the thickness of thin coatings and wear scars using Raman spectra in spot and line modes. The calculated thickness compared well with stylus profilometry values and complement it by determining thickness, not physical height. •Investigated lubricated sliding wear of DLC in Krytox lubricant with in situ Raman tribometry. The Raman carbon (DLC coating) and silicon (substrate) signals were monitored during sliding using a line scan attachment. It was determined the coating wears linearly until failure based on increasing Si:C intensity ratios. The in situ Raman line map profiles inside the wear track showed the coating wore unevenly based on mapping Si to C intensities, and there were no detectable transfer films inside the contact, just a hydrodynamic boundary film. 1/95-6/00: Research Assistant/Teaching Assistant, Department of Metallurgical and Materials Engineering, The University of Alabama. •Designed and constructed a dual ion beam assist technique in high vacuum to deposit ultrathin hard coatings and solid lubricant films. •Demonstrated experimentally that discrete amounts of substitutional nitrogen incorporated into dc/rf sputtered and ion beam deposited diamondlike carbon thin films dramatically improve the resistance to wear, resistance to plastic deformation, and lower the friction coefficient. 2 •Determined that depth-sensing reciprocating scratch tests on protective overcoats can produce repeatable and accurate wear and friction properties down to 20 Å film thickness. •Performed the first set of experiments to compare different contact loading regimes on the wear and friction properties of ultrathin films using Nanoindenter II nanoscratch option and an IBM home-built microwear scan technique. •Developed a technique to measure ultrathin (<50 Å) film coverage of underlying magnetic media using Angle-Resolved XPS. •Conducted extensive depth-sensing nanoindentation measurements of many mechanical properties of thin films including hardness, elastic modulus, and strain-rate sensitivity. •Experienced in many structural characterization techniques including high and low angle x-ray diffraction, FE-SEM with EDXS, AFM, spectroscopic ellipsometry, XPS/VBXPS/AES, Raman spectroscopy, and Fourier transform IR spectroscopy. 1/99-6/99: Research Scientist/Engineer, IBM, Almaden Research Center, San Jose, CA. •Conducted extensive wear testing using an unique IBM built system on 10 (first time reported) to 60 Å thick protective overcoats on rigid disks, e.g., ion beam deposited CHx, CHxNy, CNx, sputtered CHx, CNx, BCx, BCxNy, SiNx. •Established a new wear rate ranking methodology for sub 60 Å thick overcoats with 1 Å resolution using Auger electron spectroscopy measurements within the wear track. •Analyzed the effects of biasing, ion energy, nitrogen concentration and depositing seed layers on mechanical wear strength and friction. •Determined experimentally by AFM and HRSEM that the failure mechanisms are different for ultrathin 10 and 20 Å sputtered overcoats. •Ascertained correlations between the adhesion strength and microstructural measurements, namely density (XRR) and sp3 content (NMR), of ultrathin overcoats. 6/97-8/97: Project Engineer, Eastman Kodak Co., San Diego Laboratories. •Assisted in the design and development of innovative head/flexible media interfaces used primarily in the Advanced Photo System (APS) camera film. •Performed tribological studies of sliding surfaces including compliance, wear, and reliability testing. •Conducted experiments involving the contouring of MR read and inductive write heads. 8/94-1/95: Quality Control Engineer, The Martin Guitar Co. Inc., Nazareth, PA •Developed a comprehensive set of specifications for guitar strings used for incoming inspection of materials. •Conducted material characterization tests using an Instron mechanical tensile testing machine. 5/94-8/94: Laboratory assistant, Department of Ceramic Science and Engineering, The Pennsylvania State University. •Assisted graduate students on the characterization of Carborundum SiC fibers to be used in fiber-reinforced ceramic matrix composites. 3 AWARDS AND HONORS 2017 Society of Tribologists and Lubrication Engineers (STLE) Al Sonntag Award for Best Paper in Solid Lubricants 2016 Teacher Scholar Award - University of North Texas 2016 Division Editor for ASM Vol. 18, 2nd edition, “Friction, Lubrication and Wear Technology” 2015-2018 Elected to Board of Directors Society of Tribologists and Lubrication Engineers (STLE) 2013-2019 Elected to Board of Directors Wear of Materials, Inc. that organizes Wear of Materials International Conferences 2013 Peter J. Blau Award for Best Poster Presentation at the 19th International Conference on Wear of Materials 2012 Gordon Research Conference on Tribology, Waterville, ME, Chairman’s Fund Award (Speaker) 2011 Distinguished Alumni Award, Department of Metallurgical and Materials Engineering, The University of Alabama. 2011 Society of Tribologists and Lubrication Engineers (STLE) Al Sonntag Award for Best Paper in Solid Lubricants. 2010 Gordon Research Conference on Tribology, Waterville, ME, Chairman’s Fund Award (Session Chair) 2009 UNT Top External Funding Recipient Number 3 (out of 1064 Professors). 2008 Gordon Research Conference on Tribology, Waterville, ME, Chairman’s Fund Award (Speaker) 2007 New Faculty Grant, ACS-Petroleum Research Fund 2003 invited article, “Role of Third Bodies in Friction and Wear of Protective Coatings” in the special issue of Journal and Vacuum Science and Technology A devoted to the 50th anniversary of the American Vacuum Society (AVS). Best paper awards and scholarship awards with graduate students: o 2010 Society of Vacuum Coaters (SVC) Helen and Rolf Illsley Scholarship Fund of the SVC (Hamidreza Mohseni, PhD student); o 2010 and 2011 Society of Tribologists and Lubrication Engineers (STLE) 65th and 66th Annual Meetings & Exhibitions, No. 1 student poster presentation for superior scientific and presentation quality (Hamidreza Mohseni, PhD student).
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