Processing and Performance of Materials Using Microwaves, Electric and Magnetic Fields, Ultrasound, Lasers, and Mechanical Work – Rustum Roy Symposium: Session I
Sponsored by: ACerS Basic Science Division
Program Organizers: Morsi Mahmoud, King Fahd University Of Petroleum And Minerals; Dinesh Agrawal, Pennsylvania State University; Guido Link, Karlsruhe Institute of Technology; Motoyasu Sato, Chubu University; Rishi Raj, University of Colorado
Monday 8:00 AM
November 2, 2020
Room: Virtual Meeting Room 19
Location: MS&T Virtual
Session Chair: Morsi Mahmoud, King Fahd University of Petroleum and Minerals; Daudi Waryoba, Penn State
8:00 AM
Deforming Polycrystalline Ceramics by Dislocation Based Plastic Deformation: Lukas Porz1; Michael Scherer1; Wolfgang Rheinheimer1; Atsutomo Nakamura2; Jürgen Rödel1; 1Technical University of Darmstadt; 2Nagoya University
Dislocation-based plastic deformation of polycrystalline ceramics, which is possible at high temperatures, both gives the opportunity to shape ceramics and to introduce dislocations to tune their functional properties. Deformation is, however, much less known for ceramic polycrystals than compared to single crystals. For many materials it is still unclear to which extent this is even possible. Using polycrystalline SrTiO3 as model material, we demonstrate that deformation of several percent is achievable. By analyzing the samples and determining dislocation densities with high voltage electron microscopy, the process can be clearly linked to dislocation movement. A detailed discussion of the mechanical behavior at elevated temperature is presented including stress-strain curves at different temperatures and different strain rates. Hence, a parameter range in which plastic deformation is possible is benchmarked. Obtained dislocation densities are also discussed in the context of tuning functional properties such as electric and thermal conductivity.
8:20 AM
Laser Processing Cokes and Chars: Randy Vander Wal1; Joseph Abrahamson1; 1Penn State University
Laser processing of materials is not new, but, using lasers to anneal, bond and otherwise transform carbons is. Fundamental understanding of the dependence upon carbon structure, morphology and chemistry is critical to implementing this technology into manufacturing and processing applications. In this work a Q-switched Nd:YAG laser and a continuous wave CO2 laser are used to anneal anthracene coke and sucrose char. Anthracene coke and sucrose char were selected for laser annealing because they represent a model graphitizable and non-graphitizable carbon, respectively. Lasers provide rapid heating and cooling with high temporal control. The extent of transformation is kinetically controlled by time above the threshold temperature for transformation. Enabling the annealing trajectories from these two very different carbon materials to be followed with respect to time above temperature. To resolve the nanostructure changes HRTEM is employed. Results are compared with RexaxFF.
8:40 AM
Laser Ablation & Passivation of Aluminum Alloys: Robert Lavelle1; David Rearick1; Melissa Klingenberg1; David Snyder1; Joshua Fox1; Austin Witt2; Joshua Robinson2; 1Penn State University; 2NSWC Crane
6061-T6 and 5052-H32 aluminum components are treated using a hexavalent chromium (Cr+6) conversion coating to act as a barrier for corrosion and to enhance paint adhesion. This type of coating can cause health risks and requires special treatment, especially regarding disposal of waste products. Media blasting is also used for removing damaged paint and corrosion during the overhaul of components. While media blasting is effective, the process requires the use of consumable media and can cause damage to critical components. The objective of this study is test, validate, and implement laser ablation and hyper-passivation technology for removal of Cr+6-containing coatings and replacement of aluminum surface treatments. We seek to identify the testing requirements that must be met to obtain approval for coating removal and corrosion barrier applications. This presentation will discuss the testing needs, preliminary results, and equipment being used for testing. DISTRIBUTION ADCN 43-6002-19
9:00 AM
Recent Developments In Microwave-metal Discharge Based Machining Process and Associated Challenges: Anurag Singh1; Gaurav Kumar1; Apurbba Sharma1; 1Indian Institute of Technology Roorkee
In recent times, microwave energy-based processes have been found to be more energy-efficient, faster, and yielding equal or better quality products compared to conventional processes. This article provides an overview of the microwave-metal discharge based machining process, which involves the interaction of a sharp metallic tool with microwaves to trigger microwave-metal discharge and resulting high-temperature plasma to cause ablation of the targeted zone of the workpiece. This novel process has demonstrated the capability to drill thick non-metallic plates rapidly, but holes drilled in metallic materials are currently limited to thin sheets. Generation of repeatable, continuous, stable, and concentrated microwave-metal discharge-induced plasma and minimization of thermal damage are primary challenges during drilling of both the non-metallic and metallic materials. The exploration into factors affecting the characteristics of microwave-metal discharge-induced plasma as well as development in the tooling design of the process is future scope ahead.
9:20 AM
Study of Mechanical Properties of Microwave Processed Biodegradable Metal Composites: Shivani Gupta1; Apurbba Sharma1; Dinesh Agrawal2; Inderdeep Singh1; 1Indian Institute of Technology Roorkee; 2The Pennsylvania State University
Magnesium is an excellent candidate for intracellular cation applications in the human body. It is an essential cation for good health as it regulates the percentage of calcium and phosphorous in human bone. In this work, A-Z series magnesium alloy (AZ31) and its composite with hydroxyapatite (HA) were used as targeted materials due to their properties suitable for artificial bone material. These composites were processed using powder metallurgy route assisted with microwave heating. Further, the microwave sintered samples were investigated for their physical, compositional, and mechanical properties. X-ray diffractometry for composition and scanning electron microscopy for microstructure analysis were used. Mechanical properties such as microhardness and compressive strength were measured and compared with the human bone. It was found that the microwave sintered composites can be used as a substitute material for biodegradable implants, which are widely used for healing the malfunctioned tissues.
9:40 AM
Microwave-assisted Hydrothermal Carbonization of Switchgrass and Low Rank Coals for Solid Fuel Production: Pranjali Muley1; Christina Wildfire1; Dushyant Shekhawat1; 1National Energy Technology Laboratory
Hydrothermal carbonization is a thermochemical process used to convert biomass to carbon materials and solid fuels. Switchgrass biomass and low rank coals (lignite) were treated by co-hydrothermal carbonization to produce hydrochars using advanced microwave heating. We studied one coal to biomass ratios (50% biomass loading) at three different processing temperatures (220, 240, 250°C) and reaction times (20, 30 and 40 min) in tap water as solvent in a batch microwave reactor. The resulting liquid and solid products were analyzed for yields and quality. Co-HTC results in high carbon containing hydrochar. Mass hydrochar yields decrease with increasing temperature but carbon content of char increases as temperature and processing times increase. Addition of coal has a synergistic effect during co-HTC, enhancing the rate of carbonization. Microwave heating reduced the processing times compared to conventional heating and promotes high-value hydrochar production.
10:00 AM
The Effect of Microwave Sintering on Additively Manufactured Ceramics: Maxwell Telmer1; Tania Slawecki2; Edgar Mendoza1; Dinesh Agrawal2; B. Reeja Jayan1; 1Carnegie Mellon University; 2Penn State University
This work studies the effect of combining the techniques of Additive Manufacturing (AM) and Microwave (MW) sintering has on the final density and microstructure of Al2O3 and SiO2 parts. AM of ceramics is tricky due to the high thermal stability of ceramic particles, which tends to eliminate most conventional AM processes used on polymers (e.g., extrusion) and metals (e.g., selective laser sintering). Because of this limitation, we are interested in other AM processes that are capable of generating ceramic parts, namely binder-jetting and stereolithography. Further processing is required to improve the density and structural stability of these parts. MW sintering was explored here as a method to heat treat the AM parts because previous work from Dr. Agrawal shows that MW sintering leads to higher densities than conventional sintering. It is also a densification method that does not require applied pressure (e.g., in hot isostatic pressing), allowing for complex geometries.
10:20 AM Invited
Ionic and Mixed Ionic Electronic Conductor Oxides for Microwave Active Catalysis: Christina Wildfire1; Anthony Carter2; Edward Sabolsky2; Dushyant Shekhawat1; Daniel Haynes1; 1National Energy Technology Laboratory; 2West Virginia University
Microwave (MW)-enhanced catalysis is a promising research area that is quickly gaining interest for a wide-range of chemical reactions. Most traditional heterogeneous catalysts are based on metal oxides supported with dispersed metallic particles which do not always heat and respond to the electromagnetic field used in the microwave reactors. Therefore, catalyst design must be optimized to maximize the field interaction with the catalyst. A series of materials typically used for fuel cells like doped-ceria and -zirconia, and perovskite lanthanum with and without metallic particles were investigated for their catalytic properties for methane conversion under traditional thermal and MW methods. Generally the materials were not active for methane conversion under traditional methods, at the reaction conditions studied, while the microwave reactor usually provided a complete conversion for some of the material used. Under microwave conditions, the selectivity of methane conversion varied, and the characterization of these catalyst will be discussed.