SEMINAR: Advanced Powder Processing for Energy Applications

DR. Somayeh Pasebani, Innovation Engineer, North American Hoganas, Inc.
When Feb 11, 2016
from 11:00 AM to 12:00 PM
Where Sackett Hall, Room 200
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Abstract

Part I: Oxide dispersion strengthened (ODS) alloys are potential candidates to be used as high temperature structural materials because of highly stable microstructure and high creep strength due to dispersion of ultrafine Y–Ti–Ο−enriched particles. The traditional processing method of ODS alloys is via mechanical alloying (MA) of high chromium content powder in combination with up to 0.5 wt.% Y2O3, followed by hot consolidation via hot extrusion or hot isostatic pressing. In PhD research, Fe-based ODS were developed by using spark plasma sintering (SPS). Furthermore, in Fe-based ODS alloys or so-called nanostructured ferritic steels, Y2O3 was replaced by equal atomic percent of La2O3. Then, the effects of alloying composition, processing parameters including milling parameters and sintering parameters, on the microstructure characteristics and mechanical properties of the milled powder and consolidated alloys are investigated and structure–properties were correlated. Lanthanum oxide (0.5 wt.%) was added to Fe–14Cr leading for improving microstructural stability and mechanical properties mainly due to a high number density of La–Cr–O-enriched nanoclusters (NCs). The combined addition of La, Ti (1 wt.%) and Mo (0.3 wt.%) to the Fe–14Cr base composition further enhanced the microstructural stability and mechanical properties. Formation mechanism of these NCs can be explained through the concentrations and diffusion rates of the initial oxide species formed during the milling process and initial stages of sintering as well as the thermodynamics nucleation barrier and their enthalpy of formation. Significant densification occurred at temperatures greater than 950 oC with a relative density higher than 98%. High mechanical strength values were achieved in room and high temperature are due to the combined strengthening mechanisms of work hardening, grain refinement, dispersion strengthening and solid solution strengthening.

Part II: In this part, research plans, teaching plans and service plans for a career faculty at University of Louisville are discussed. Examples of some research areas, potential funding sources and undergraduate and graduate teaching courses are propounded.

Speaker's Biography

Dr. Somayeh Pasebani has received her PhD in Materials Science and Engineering from University of Idaho in August 2014 where she developed high temperature materials for energy application via powder processing and advanced sintering techniques. After graduation, she joined North American Hoganas Inc. as an Innovation Engineer to contribute to research and development in metal/alloy powder manufacturing industries.  Her academic background and her industrial exposure have equipped her with the right tools to establish a new research program in advanced manufacturing. Prior to joining University of Idaho, she has received her BS in Metallurgical Engineering and MS in Materials Science from Isfahan University of Technology where she focused on severe plastic deformation and producing ultrafine-grained materials.