Sanderson Building, Classroom 2
The fundamental purpose of Functional Ceramics Technology is to obtain 100% dense polycrystalline covalent nonoxide ceramics with a grain size <100 nm at the lowest possible temperature, as quick as possible. Today, I report a new method, called “Flash Sintering’, which utilizes a low applied electric field on nano/micro B4C powder, at low temperature <1000 oC, to obtain a properly sintered ceramic, dense with a small grain size. The applied electric field helps to reduce the sintering temperature by at least a factor of three within a time frame measured in minutes/seconds rather than hours/days.
This presentation will focus on the B4C system, however, other nonoxide ceramics nanocomposites, such as; ZrB2, TiB2, Si3N4, SiC, BN, and their combinations, will be reviewed. In addition, I will present results of an in situ time-resolved Energy Dispersive X-Ray Diffraction (EDXRD) study, using synchrotron radiation of 200 keV photons, as a function of electric field and temperature. Flash sintered nano-B4C particulate system demonstrates an anomalous lattice expansion accompanied by a maximum current draw with an increase in density up to 99%.
The effectiveness of the sintering method, which relies on the understanding of the conductivity mechanism of non-oxide ceramics, will also be discussed. Applications of the B4C ceramics in this flash sintering processing, exhibiting small grain size including, but not limited to ballistic armor, will be shown. Results will also include in situ EDXRD studies of oxides: yttria doped zirconia (Y2O3-ZrO2), barium titanate (BaTiO3), and hydroxyapatite nanocrystals with TiO2 for biomedical applications. A brief modeling will be demonstrated in relation to phenomenological landscape of the anomalous mass transport discovered by the in-situ synchrotron diffraction study, which includes the anomalous lattice expansion and associated high diffusion rates under electric field.
- Ph.D.: MSE, Northwestern Univ., Evanston, Illinois: Thesis Advisor Prof. John Hilliard: “Interdiffusion & Enhanced Modulus Effect in Composition Modulated Copper-Nickel Thin Foils”: 1977
- BS: Physics Dept, Univ. of Athens, Greece: 1972.
Areas of Research
Sintering of Engineering Materials; in-situ and Operando Synchrotron Probe of Commercial Batteries and other Novel Engineered Materials; Armory Applications; Electric Field and Pressure Assisted Processing of Inorganic and Nonmetallic Solids; Synchrotron Strain and Phase Mapping of Nuclear Materials; Field Testing of Infrastructure Materials; NanoBiotechnology; Thermal Spray Technology of Nano Coatings and Films; Strain and Phase Mapping by Light Source Synchrotron Radiation; Residual Stress Measurements by EDXRD; Micromechanics, Phase Field Model, Nanocomposites.
Current co-recipient of Defense National Initiative on Flash Sintering with Boulder University in Colorado. Researcher in the field of Nanostructured Materials and Technology for over 30 years. Co-founder and Editor-in-Chief of the Nanostructured Materials Journal for over ten years, publishing 12 volumes of scientific work in Nanomaterials Research. Contributing participant of several National and International initiatives in Nanotechnology. Chair and Organizer of over 50 International Conferences, most recent, 2012 International Conference on Nanostructured Materials held in Rhodes, Greece of approximately 1000 participants. Industrial applications include pharmaceutical, chemical, communications, manufacturing, defense, transportation, energy, offshore , aircraft and airspace.
Professional Work Experience
- July/77 – Present, Distinguished Professor, Rutgers The New Jersey State University, Dept. of Materials Science and Engineering, Piscataway, New Jersey
- Sept/90-Dec/00 – Editor and Chief for Nanostructured Materials Journal, Elsevier Publishing
- Sept/91-Present – Director for Nanomaterials Research Laboratory, Rutgers University, ENGA100, Busch Campus, Piscataway, New Jersey
- 1972-1977 Northwestern University, Materials Science and Engineering, Research Assistant
Event Contact Name:
Francisco Garcia Garcia