Advances in Powder and Ceramic Materials Science: Advances in Ceramic Materials and Processes II
Sponsored by: TMS Extraction and Processing Division, TMS Materials Processing and Manufacturing Division, TMS: Materials Characterization Committee, TMS: Powder Materials Committee
Program Organizers: Bowen Li, Michigan Technological University; Dipankar Ghosh, Old Dominion University; Eugene Olevsky, San Diego State University; Kathy Lu, University of Alabama Birmingham; Faqin Dong, Southwest University of Science and Technology; Jinhong Li, China University of Geosciences; Ruigang Wang, Michigan State University; Alexander Dupuy, University of Connecticut
Tuesday 2:30 PM
March 21, 2023
Room: 30A
Location: SDCC
Session Chair: Ruigang Wang, University of Alabama; Faqin Dong, Southwest University of Science and Technology
2:30 PM Introductory Comments
2:35 PM Invited
Energy Efficient Spark Plasma Sintering Fabricating Transparent Alumina: Eugene Olevsky1; CheolWoo Park1; Elisa Torresani1; Chris Haines2; 1San Diego State University; 2US Army DEVCOM - Army Research Laboratory
In this study, spark plasma sintering (SPS) technology with three configurations -one traditional and two different energy efficient- was used to produce transparent alumina. The results in terms of sample properties and energy saving were analyzed and compared. In an energy efficient configuration involving a boron nitride coated graphite foil, the power used during the SPS process significantly decreases, but cracks appear in most samples. A new energy efficient configuration was capable of preventing the crack formation, achieving specimens’ full densification and uniform transparency in alumina. Also, the new method reduces energy consumption compared to the traditional SPS configuration. The developed method has the potential for fabricating transparent ceramic of various materials with uniform transparency. The conducted studies include the development of a model, based on the continuum theory of sintering, that can predict the density and grain growth evolution during the sintering process.
2:55 PM Invited
Developing Transparent Ceramics for Laser Power Scaling and Laser Welding: Y Kodera1; Xingzhong Wu1; E. Penilla1; Javier Garay1; 1UCSD
Transparent ceramics are well established alternatives to single crystals and glasses for a variety of applications such as transparent armor and laser gain media. We describe our ongoing efforts in processing transparent ceramics for high thermal conductivity laser gain media. In addition, we will discuss an ultrafast pulsed laser procedure we developed for welding ceramics. The laser gain materials have comparable absorption/emission characteristics to rare earth doped YAG but improved thermal conductivity, allowing more laser power. The ceramic laser welding procedure relies on focusing light on interfaces to ensure an optical interaction volume in ceramics to stimulate linear/nonlinear absorption processes, causing localized melting rather than ablation. The key is the interplay between linear and nonlinear optical properties and laser energy–material coupling. We show that tuning optical transparency (absorption and scattering) allows focusing of laser light into the ceramics, placing the energy where it can cause localized melting at the interfaces.
3:15 PM
Fabrication of Ultra-lightweight and Highly Porous Alumina Scaffolds by a Novel Sol-gel/Freeze-casting Hybrid Method: Pei-Chieh Ho1; Haw-Kai Chang1; Po-Yu Chen1; 1National Tsing Hua University
Ceramic-based scaffolds developed by the freeze casting method exhibit anisotropic lamellar and interconnected porous structure and can be adopted for filtration, insulation, absorption and many applications. However, the upper limit of porosity caused by the wetting ability of ceramic powders has restricted functionalities of scaffolds fabricated by the traditional freeze-casting method. In this study, the sol-gel/freeze-casting hybrid method was developed to fabricate the alumina scaffolds with low bulk density (200-500 kg/m3) and proper specific strength. The microstructural features of the lamellar structure and continuous surface developed from the condensation reaction were evaluated by SEM. The ultra-lightweight porous alumina scaffolds successfully fabricated by this hybrid method show high specific surface area and proper mechanical stability. The porosity of alumina scaffolds can reach over 90%, possessing great potential for filtration and gas absorption applications in the future and this hybrid sol-gel/freeze casting approach can be extended to ceramic/glass scaffolds with varying functionalities.
3:35 PM
Plasma Sprayed Carbon Nano Fillers Reinforced Lanthanum-cerate Hybrid Composite Coating with Outstanding Toughness: Pushpender Singh1; Niranjan Pandit1; Anup Kumar Keshri1; 1Indian Institute of Technology Patna
Graphene nanoplatelets (1 wt. %) and carbon nanotube (0.5 wt. %), and reinforced lanthanum cerate (La2Ce2O7) matrix, as well as their involvement in overcoming the primary constraints of the La2Ce2O7 (LC) coating. LC coatings have been deposited on the Inconel-718 substrate using the atmospheric plasma spray technique (APS). We report an exceptionally high fracture toughness (8.04 ± 0.2 MPa m0.5) value for an LC coating prepared reinforced by GNPs (1 wt. %) and CNTs (0.5 wt. %); the enhancement in fracture toughness was noted to be ~500% compared to all previous works. Several factors, viz. uniform distribution of GNPs and CNTs in La2Ce2O7 matrix, stabilization of cubic fluorite La2Ce2O7 phase, and various associated toughening mechanisms offered by GNPs and CNTs were attributed to this enhancement. Apart from it, the thermal shock resistance of LCGC coating performed at 1800 °C showed 1721 numbers of cycles before the partial delamination of the coating.
3:55 PM Break
4:10 PM Invited
Surface-engineered Metal Oxide Nanocrystals: Redox Chemistry, Catalysis and Beyond: Ruigang Wang1; 1The University of Alabama
Catalyst-support interaction and interface play a critical role in heterogeneous catalysis. Support materials usually help enhance catalyst dispersion and thermal stability. In recent years, promoting effects of multivalent reducible oxide supports have gained significantly increasing research interests. Among these reducible oxides, CeO2 along with other oxides constitutes an important class of catalyst supports that can exchange oxygen rapidly under variable reducing or oxidizing conditions, which is mainly accomplished by a reversible valence change of the cerium ions with formation or elimination of oxygen vacancies. In this talk, I will present some recent progress on (1) synthesis and redox chemistry characterization of shape/crystal structure-controlled CeO2 support materials, (2) chemical etching surface modification of CeO2, and (3) understanding the catalyst-support interaction and support promoting effect for many industrial catalysis and energy storage applications such as in vehicle exhaust clean-up, carbon dioxide capture, and host materials of Li-S battery.
4:30 PM
Energy Dispersive X-ray Diffraction with Synchrotron Radiation for Measurement of Residual Elastic Mismatch Strain in Composites and Coating Systems for Extreme Environments: John Ferguson1; J.Y. Peter Ko2; Kelly Nygren2; Michael Sangid1; 1Purdue University; 2Materials Solutions Network at CHESS
Energy dispersive X-ray diffraction (EDD) conducted at a high-energy synchrotron source is a powerful tool to determine bulk elastic strain in engineering materials. Residual elastic strain, resulting from the joining of multiple materials with thermal expansion mismatch, can be prevalent and detrimental to component performance. This work leverages the benefits of EDD for characterization of residual elastic mismatch strain resulting from processing and thermal exposure in two different composites for extreme environments. First, a WC-Cu ceramic-metal composite with high thermal conductivity and strength is analyzed for the relaxation of processing-induced residual tensile stress in the copper phase by subsequent thermal cycling. Next, the depth resolved residual elastic strain in two rare-earth oxide stabilized zirconia (12 mol % yttria and 6 mol % samaria) coatings, applied to a carbon-carbon composite substrate, is determined and compared between as-plasma sprayed and post-ablation torch exposed specimens.
4:50 PM
Effect of Y2O3 and Al Addition on Mechanical Properties and Micrographic Features of Invar Based ODS Alloy Prepared by Mechanical Alloying + Spark Plasma Sintering: Arpan Arora1; Suhrit Mula1; 1IIT Roorkee
In the present study, mechanical properties and micrographic features were studied on three compositions: Fe-42Ni-2Zr, Fe-42Ni-2Zr-2Y2O3, and Fe-42Ni-2Zr-2Y2O3-2Al. All the three compositions were prepared using mechanical alloying via high energy ball mill and consolidated through spark plasma sintering at 1100 °C, with an applied load of 60 MPa. All the sintered samples were mirror-polished using colloidal silica, and EBSD (Electron Backscatter Diffraction) scan was conducted to understand the micrographic features and micro-strain using Kernel Average Misorientation. micrographic features were correlated with mechanical properties using Vickers hardness. Diffusional annealing was conducted on the sintered sample at a temperature of 1200 °C under an argon atmosphere to understand the grain growth mechanism and thermal stability. XRD was conducted to understand phase formation, microstrain, and change in crystallite size in sintered sample with respect to annealed sample. Orowan strengthening and Zenner pinning played a vital role in high-temperature thermal stability and grain refining.