RUI: Studies of the Heating and Sintering of Powdered Metals in Separate Electric and Magnetic Fields Using a Single Mode Microwave Cavity Darin T. Zimmerman, Pennsylvania State University, Altoona College, DMR 0406584 HYPOTHESIS: Metal particles act as individual absorbers and are rapidly heated by microwave field-induced currents. High local heating causes particles to coalesce, subsequently resulting in reduced absorption. t ~ 5 s OBSERVATION: Powdered metal compacts (copper) may be heated and pre-sintered in seconds by microwave fields. (a) Unheated; (b) Heated in electric field for 26 s; (c) Heated in magnetic field for 9 s. EVIDENCE: Microwave absorption in a powder metal compact depends on powder particle diameter, peaking near 8 μm, in agreement with theory. Compacts made from larger diameter particles (or those without an oxide layer) do not behave as individual absorbers due to electrical contact
Darin T. Zimmerman, Pennsylvania State University, Altoona College, DMR 0406584
Feb 09, 2016
OBSERVATION : Powdered metal compacts (copper) may be heated and pre-sintered in seconds by microwave fields. (a) Unheated; (b) Heated in electric field for 26 s; (c) Heated in magnetic field for 9 s. t ~ 5 s. - PowerPoint PPT Presentation
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RUI: Studies of the Heating and Sintering of Powdered Metals in Separate Electric and Magnetic Fields Using a Single Mode Microwave Cavity
Darin T. Zimmerman, Pennsylvania State University, Altoona College, DMR 0406584
HYPOTHESIS: Metal particles act as individual absorbers and are rapidly heated by microwave field-induced currents. High local heating causes particles to coalesce, subsequently resulting in reduced absorption.
t ~ 5 s
OBSERVATION: Powdered metal compacts (copper) may be heated and pre-sintered in seconds by microwave fields. (a) Unheated; (b) Heated in electric field for 26 s; (c) Heated in magnetic field for 9 s.
EVIDENCE: Microwave absorption in a powder metal compact depends on powder particle diameter, peaking near 8 μm, in agreement with theory. Compacts made from larger diameter particles (or those without an oxide layer) do not behave as individual absorbers due to electrical contact between particles.
RUI: Studies of the Heating and Sintering of Powdered Metals in Separate Electric and Magnetic Fields Using a Single Mode Microwave Cavity
Darin T. Zimmerman, Pennsylvania State University, Altoona College, DMR 0406584
Zimmerman research group (L to R): JunKun Ma, Nicholas Miskovsky, Chris Lynch, Kelly Martin, Chuck Smith, Gary Weisel, Darin Zimmerman. Not shown: John Diehl, Brock Weiss, Earnie Johnson.
EDUCATION
4 undergraduate researchers: John Diehl, Chris Lynch, Kelly Martin (now pursuing M.S. in Materials within our group), Chuck Smith.
Postdoctoral researcher: JunKun Ma (now on the tenure-track at Eastern Louisiana Univ.)
EXPERIENCE
Students and postdoc gained experience in microwave techniques and characterization, data acquisition and analysis, computer simulations, and dissemination of results.
DISSEMINATION
2006 March Meeting of the American Physical Society (posters by Lynch and Martin)
PM2006 World Congress on Powder Metals (undergraduate co-authors Diehl, Martin, and Smith)
2006 COMSOL Conference (undergraduate co-authors Martin and Smith)
Journal of Applied Physics 101, 074906 (2007). Undergraduate co-authors, Diehl, Martin, and Smith.
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