Nanoindentation of Ultraprecision Surfaces - CDII

DIPARTIMENTO DI INGEGNERIA INDUSTRIALE
Seminario
Nanoindentation of
Ultraprecision Surfaces
Prof. Don A. Lucca
School of Mechanical and Aerospace Engineering,
Oklahoma State University (U.S.A.)
19 maggio 2016, ore 12.30-14.00
Aula Magna di Ingegneria
Via Loredan, 20 – Padova
Al termine del seminario il prof. Lucca presenterà agli interessati:
Opportunities for Funded Doctoral Studies
in the Ultraprecision Surfaces Laboratory at Oklahoma State University
Tutti gli studenti sono invitati a partecipare.
In particolare, il seminario è rivolto agli studenti dei corsi di
Laurea Magistrale in Ingegneria Meccanica, Ingegneria dei
Materiali, Fisica, Scienze Chimiche e Scienza dei Materiali.
Servizio Didattica: via Venezia, 1 - 35131 Padova tel. +39 049 8276784 [email protected] www.dii.unipd.it
DIPARTIMENTO DI INGEGNERIA INDUSTRIALE
UNIVERSITÀ DEGLI STUDI DI PADOVA
Nanoindentation of Ultraprecision Surfaces
Don A. Lucca
Regents Professor
Carl and Gladys Herrington Chair in Advanced Materials
School of Mechanical and Aerospace Engineering
Oklahoma State University
Stillwater, OK 74078, USA
Abstract
Over the last twenty years, nanoindentation has emerged as an important method for the evaluation of
the mechanical response of small material volumes and thin films to applied loading. Whereas the
origins of the technique can be thought to have first occurred at the end of the nineteenth century, only
since the1990s have refinements to the instrumentation and methods for extracting mechanical
properties from the test enabled significant progress towards establishing nanoindentation as an
important tool. This talk focuses on the use of nanoindentation to probe the material response of ultrafinely finished surfaces to indentation loading. Results from experiments on single crystal ZnO and
CaF2 which were produced by several fine finishing processes are presented. The abrupt increase in
indenter penetration at a given load, referred to as “pop-in” observed for the surfaces, and attributed to
dislocation nucleation and the onset of yielding was used to provide insight into the subsurface
condition. Both the onset of pop-in and near surface hardness were found to correlate with the severity
of surface preparation. Mechanical polishing was seen to suppress pop-in and mechanically polished
surfaces were found to exhibit yielding at the initiation of loading. Hardness was found to be dependent
on surface preparation with increased hardness observed for increased surface preparation severity.
Hardness also exhibited a near surface depth dependence. Results from nanoindentation experiments
used to reveal a surface photoplastic effect and dislocation rosettes in ZnO are also presented.
Biography
Don A. Lucca is currently Regents Professor and Carl and Gladys Herrington Chair in Advanced
Materials in the School of Mechanical and Aerospace Engineering at Oklahoma State University. He
also holds the position of Guest Scientist in the Center for Integrated Nanotechnologies Group in the
Materials Physics and Applications Division at Los Alamos National Laboratory. He received a BS
degree from Cornell, MSE from Princeton, and PhD from RPI all in Mechanical Engineering.
Professor Lucca is a Fellow of CIRP, SME and ASME. He has served on the Board of Directors of
the American Society for Precision Engineering and the North American Manufacturing Research
Institution. He is a recipient of the Alexander von Humboldt Research Award for Senior Scientists,
and has held positions of Visiting Professor at the Stiftung Institut für Werkstofftechnik at Universität
Bremen and at the Politecnico di Torino. He was awarded a Mercator Professorship by the Deutsche
Forschungsgemeinschaft in Germany, the Russell Severance Springer Professorship in Mechanical
Engineering at the University of California, Berkeley, and the SME Frederick W. Taylor Research
Medal, and holds an honorary doctorate from Universität Bremen.
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DIPARTIMENTO DI INGEGNERIA INDUSTRIALE
UNIVERSITÀ DEGLI STUDI DI PADOVA
Opportunities for Funded Doctoral Studies
in the Ultraprecision Surfaces Laboratory at Oklahoma State University
Don A. Lucca
Regents Professor
Carl and Gladys Herrington Chair in Advanced Materials
School of Mechanical and Aerospace Engineering
Oklahoma State University
Stillwater, OK 74078, USA
Abstract
The research efforts of the Ultraprecision Surfaces Laboratory at Oklahoma State University are
directed towards 1.) developing basic understanding of the mechanics and physics which govern
processes used to create ultraprecision surfaces and thin films, and 2.) the investigation of the
mechanical, chemical, electrical and photonic nature of the surfaces which result. Specifically, studies
have focused on: creation of ultraprecision surfaces and thin films by mechanical and
chemomechanical polishing, nanometric cutting, ultraprecision machining, photoelectrochemical
etching, sol-gel deposition, laser recrystallization and ion beam modification. Studies involve
investigation of both the surface and near surface state in terms of topography, chemistry, structure,
and mechanical, electrical and photonic properties. Our group utilizes various techniques to probe the
nature of the surface including ion backscattering spectroscopy, nanoindentation, photoluminescence
spectroscopy, Raman spectroscopy, scanning electron microscopy, transmission electron microscopy
and various scanning probe microscopies. The nature of our work is inherently interdisciplinary and
involves materials science, chemistry, applied physics and engineering. In this talk, some of the recent
research performed by our group will be discussed, as well as current opportunities for highly
competitive Graduate Research Assistantships which enable pursuit of the Ph.D. degree as a fullyfunded graduate student in the group.
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