Processing and Performance of Materials Using Microwaves, Electric and Magnetic Fields, Ultrasound, Lasers, and Mechanical Work – Rustum Roy Symposium: Session I
Program Organizers: Morsi Mahmoud, King Fahd University of Petroleum And Mineral; Dinesh Agrawal, Pennsylvania State University; Guido Link, Karlsruhe Institute of Technology; Motoyasu Sato, Chubu University; Rishi Raj, University of Colorado; Victoria Blair, CCDC Army Research Lab
Monday 8:00 AM
September 30, 2019
Location: Oregon Convention Center
Session Chair: Morsi Mahmoud, King Fahd University of Petroleum and Minerals (KFUPM); Jun Fukushima, Tohoku University
Radio Frequency and Microwave Heating of Preceramic Polymers and its Application in Silicon Carbide Processing: Nutan Patil1; Miladin Radovic1; Mohammad Saed2; Micah Green1; 1Texas A&M University; 2Texas Tech University
Here, we demonstrate molecular heating methods like microwave and noncontact Radio Frequency (RF) for processing of silicon carbides (SiC) via preceramic polymer (polycarbosilane) route using electromagnetic susceptors. We use these volumetric heating methods for applications in 3D printing of SiC, fiber manufacturing and ceramic matrix composite (SiC/SiC) manufacturing. In our work, we have focused on two susceptor types: a) Multiwalled Carbon nanotubes (MWCNT) (b) SiC fibers. We show that polycarbosilanes have minimum response to RF and addition of susceptor like MWCNT results in rapid heating of these polymers. We also report for the first time change in dielectric constant and AC conductivity of the polycarbosilane-MWCNT composites as it heats and transforms. We tested dielectric heating response of commercial SiC fibers (Hi-Nicalon and Syramic type) and SiC nano particles. SiC fibers (Hi-Nicalon) show high dielectric heating and can be used to cure ceramic matrix composites
Effect of Pulsed Electric Current on Metastable Austenitic Steel: Hye-Jin Jeong1; Ju-Won Park1; Howook Choi1; Moon-Jo Kim2; Sung-Tae Hong3; Heung Nam Han1; 1Seoul National Univ; 2Korea Institute of Industrial Technology; 3University of Ulsan
Electrically-assisted Manufacturing (EAM) is a newly emerging metal processing technology since it can obtain properties or formability of metals, which cannot be achieved with traditional thermomechanical processes, by applying electric current. Moreover, since the EAM capable of rapid heating can be applied to various processes without any large area or line change in existing processes, it can significantly improve process efficiency. In this study, the tensile deformation behavior of 301L stainless steel containing metastable austenite under pulsed electric current was investigated. The relationship between the mechanically induced martensitic transformation (MIMT) of metastable austenite and pulsed electric current was analyzed by using an X-ray diffractometer (XRD) and a field emission gun scanning electron microscope (FE-SEM) equipped with an electron backscatter diffraction (EBSD). We discussed in detail the effect of pulsed electric current on the elongation in relation to MIMT, reverse transformation and electric current-induced annealing.
8:40 AM Invited
Electro-pulse and High Magnetic Field Annealing of Cold-Rolled NiFe: Ian Baker1; Patrice Chantrenne2; Si Chen3; Damien Fabrègue2; Xiaobin Guo1; Nour Hayek1; Gerard Ludtka4; Bart Murphy4; Rachel Osmundsen1; Yang Ren3; Ty Teodori1; Liang Wang5; Chao Yang1; 1Dartmouth College; 2INSA Lyon; 3Argonne National Laboratory; 4Beijing Institute of Technology; 5Northern Illinois University; Beijing Institute of Technology
L1o-structured NiFe has a theoretical magnetic energy product, (BH)max, comparable to that of rare-earth magnets but costs much less. The L1o structure only occurs below about 330C and so, unfortunately, the transformation from the equilibrium high temperature f.c.c. phase takes a very long time. In this work, two novel approaches were used in an attempt to produce L1o-structured NiFe from the high temperature f.c.c. phase. The idea common to both is to heavily roll NiFe and then recrystallize it below 330C with the hypothesis that recrystallizing grain boundaries sweeping through the material will enable the low-temperature form to be produced by local atom switching. Two approaches that accelerate recrystallization were used electro-pulse annealing, and annealing in a high magnetic field. The crystal structures and microstructures obtained after using these two processing routes have been analyzed using EBSP imagining in a SEM and by synchrotron X-ray diffraction.
9:00 AM Invited
Microwave Effects in Heterogenous Materials: A Study on Catalysis: Christina Wildfire1; Dushyant Shekhawat1; Victor AbdelSayed2; Terence Musho3; 1NETL; 2Leidos, NETL; 3WVU
The use of microwaves in catalysis has shown promising results in increased yields, product selectivity, and energy efficiency but little is known of the mechanisms behind the results. It is thought that hot spot formation is a main cause but previous studies by this group has shown formation of electric fields within these materials that may be assisting in the reactions. This study investigates a group of catalysts, metal active sites on a transparent support, under a microwave field where the active sites are varied by size, distribution, and precursor. The catalysts are also tested in a variable frequency microwave reactor and their performance compared to the dielectric properties. Testing has shown better efficiency, less sintering, and quicker response times with higher metals loading. Modeling was performed to explain some non-thermal effects seen in the heterogeneous catalyst materials.
9:30 AM Invited
Electric Current Annealing of Zircaloy Alloy and Associated Mechanisms: Daudi Waryoba1; Zahabul Islam1; Baoming Wang2; Aman Haque1; 1Pennsylvania State Univ; 2Massachusetts Institute of Technology (MIT)
This study presents the microstructure and mechanisms of recrystallization during electric current annealing of Zircaloy-4 alloy. The alloy was annealed in-situ a scanning electron microscope with a current density of 5x104 A/cm2 for about 15 minutes. The investigation was performed using electron backscatter diffraction (EBSD) technique. The resulting microstructure was characterized with high angle boundaries (HAGBs) and strain-free equiaxial grains that were essentially the same as that obtained with conventional thermal annealing at 600°C for 2hrs. The accelerated recrystallization during electric current annealing is attributed to the high ‘electron-wind force’ arising from the momentum transfer between conduction electrons and defects, which creates a high atomic flux along the grain boundaries. The electron-wind force specifically targets defective regions, leading to unprecedented time and energy saving. Grain boundary rotation was noted to be the main recrystallization mechanism that caused rotation-coalescence-induced grain growth. These results were supported by the molecular dynamics simulation.
10:00 AM Break
10:20 AM Invited
Surface-charge Mobility Theory: An Explanation for Certain "Microwave Effects": Edward Ripley1; 1Y-12 National Security Complex
The term "Microwave Effect" is often used to describe when something, either advantageous or deleterious occurs in a microwave field. This talk will explore surface charge mobility theory, to see how it may explain certain "microwave effects". Microwave are simply an application of electromagnetic energy, but all too often researchers simply accept the results, good or bad, without fully understanding the mechanisms involved. This talk will attempt to answer questions such as: why bulk metals don't heat in a microwave, but powdered metals do. How certain chemical reactions can occur quickly in a microwave field and with less energy input. Once the fundamentals of this theory are understood it can be used to explain a host of electromagnetic phenomena including chemical reactions, reaction kinetics, enhanced diffusion and many more. Although this talk focuses on microwaves these principals can apply to a range of electromagnetic applications.
Advanced In-Line Nanocrystallization of Amorphous Metal Ribbon (AMR) Alloys Through Mechanical and Electromagnetic Fields: Kevin Byerly1; Paul Ohodnicki1; Michael McHenry2; Michael Lanagan3; Dinesh Agrawal3; 1National Energy Technology Laboratory; 2Carnegie Mellon Universiity; 3Penn State University
Electromagnetic assisted processing of rapidly solidified 25mm wide Cobalt-rich amorphous metal ribbons (AMRs) was performed using a custom developed thermal annealing stage. The AMR was subjected to a controlled tensioning process under a regulated value of applied stress using a reel-to-reel system. The AMR was passed through a thermal processing chamber to investigate heating in electromagnetic fields under various processing conditions, such as material speed/time in furnace, anneal temperature, and applied tension. Magnetic property test results from conventional annealing processes are compared to new, rapid in-line heating methods. Additionally, Fe-based alloys are investigated to overcome mechanical processing limitations during crystallization for conventional tension annealing processing strategies.
11:00 AM Invited
Effective Permittivity of Metal/Ceramic Composites and Microwave Heating Characteristics: Noboru Yoshikawa1; Sinya Ohgane1; Naoki Ohgane1; Takane Watanabe1; Sergey Komarov1; 1Tohoku University
Metal powder compacts can be well heated in microwave magnetic field, however they cannot be heated well anymore if sintering progresses and become dense, because they become a bulk body and microwave cannot penetrate into the internal area. On the other hand, microwave penetration depth into lossy ceramic materials is not large enough and the volumetric heating is not necessarily easy, either. The authors have studied the composite bodies composed of metal particles and low loss ceramics for attaining the rapid and volumetric heating. Measurement of physical properties of the composites such as the effective permittivity and effective conductivity was conducted and compared with their heating characteristics by microwave. In this paper, it is intended to compare and summarize the physical property – heating rate relationships of several materials’ systems.
11:30 AM Invited
Locally Activated Solution Processing Would be Preferable Than General Hydrothermal/Solvothermal Processing Using Autoclaves: Masahiro Yoshimura1; 1National Cheng kung University
Hydrothermal reactions need high temperature (T) and Pressure (P). T would be effective for kinetics via KT. However P would affect as Log P like Concentration(C) as Log C, where C can be changed in 5-8 order of magnitudes but P is difficult to change even 2-3 orders. Particularly in “Autoclaves” pressure increases would be more difficult and costly than temperature. Thus, autoclaves seems not to be always the best choice of hydrothermal reactor. Pipe-line or capillary tube may be better for continuous production. Moreover, most of Hydrothermal/Solvothermal reactions can occur at the interface between liquids and solids, therefore, they can be activated by Chemically, Electrochemistry, Sono-, Mechano-, Microwave-, Laser-, Plasma-,etc., where those activation could be locally, 1D, 2D and 3D patterning can directly form in Solution. These locally activated solution processes will be developed widely and successfully. Complex formation in solution species and solid surfaces should be considered.