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Item Extrusion Based Ceramic 3D Printing - Printer Development, Part Characterization, and Model-Based Systems Engineering Analysis(2020-12) Pai Raikar, Piyush Shrihari; Zhang, Jing; Agarwal, Mangilal; Anasori, BabakCeramics have been extensively used in aerospace, automotive, medical, and energy industries due to their unique combination of mechanical, thermal, and chemical properties. The objective of this thesis is to develop an extrusion based ceramic 3D printing process to digitally produce a casting mold. To achieve the objective, an in-house designed ceramic 3D printer was developed by converting a filament based plastic 3D printer. For mold making applications, zircon was selected because it is an ultra-high temperature ceramic with high toughness and good refractory properties. Additionally, alumina, bioglass, and zirconia slurries were formulated and used as the feedstock material for the ceramic 3D printer. The developed 3D printing system was used to demonstrate successful printing of special feature parts such as thin-walled high aspect ratio structures and biomimetically inspired complex structures. Also, proof of concept with regard to the application of 3D printing for producing zircon molds and casting of metal parts was also successfully demonstrated. To characterize the printed parts, microhardness test, scanning electron microscopy (SEM), and X-ray diffraction (XRD) analyses were conducted. The zircon samples showed an increase in hardness value with an initial increase in heat treatment temperature followed by a drop due to the development of porosity in the microstructure, caused by the decomposition of the binder. The peak hardness value for zircon was observed to be 101±10 HV0.2. Similarly, the microhardness values of the other 3D printed ceramic specimens were observed to increase from 37±3 to 112±5 HV0.2 for alumina, 23±5 to 35±1 HV0.2 for bioglass, and 22±5 to 31±3 HV0.2 for zirconia, before and after the heat-treatment process, respectively. Finally, a system model for the ceramic 3D printing system was developed through the application of the model-based systems engineering (MBSE) approach using the MagicGrid framework. Through the system engineering effort, a logical level solution architecture was modeled, which captured the different system requirements, the system behaviors, and the system functionalities. Also, a traceability matrix for the system from a very abstract logical level to the definition of physical requirements for the subsystems was demonstrated.Item Tracking the Evolution of Mid Cenozoic Silicic Magma Systems in the Southern Chocolate Mountains Region, California Using Zircon Geochemistry and Quartz and Zircon Geothermometry(2009-10-01T16:35:19Z) Needy, Sarah Katherine; Barth, Andrew, 1958-During the mid Cenozoic, the Chocolate Mountains region of southeastern California experienced crustal extension slightly before, during, and after the main pulse of magmatism. This combined with mid-late Cenozoic faulting to locally uplift plutonic rocks interpreted to represent the plumbing system(s) for volcanic units, allowing an examination of both the extrusive and intrusive result of magmatism. Zircon U-Pb ages of from six magmatic units yield late Oligocene to early Miocene ages and correlate better with stratigraphic relationships than previously compiled ages. These units are four silicic volcanic units – Quechan volcanic rocks, tuff of Felipe Pass, ignimbrite of Ferguson Wash, and tuff of Black Hills – and two plutonic units – the granites of Mount Barrow and Peter Kane Mountain. Regarding contemporaneous plutonic systems as baseline comparisons, zircons from the volcanic units commonly record plutonic temperatures; interpreted to be solidus or near solidus temperature. Remobilization may be a common process leading to eruption. Quartz and zircon thermometers reveal the ignimbrite of Ferguson Wash and tuff of Black Hills magmatic systems evolved differently. Quartz yields temperatures of 700°C to ~750°C in both units with no core-rim trends. Cores of zircons from the ignimbrite of Ferguson Wash yield temperatures between 750°C and 890°C. Zircon rim temperatures are between 875°C and 950°C. Tuff of Black Hills zircon cores generally record temperatures of ~850°C and zircon rim temperatures are ~700°C. Rims from tuff of Black Hills zircon record the same temperature range as zircons from coeval granites. The temperature increase from core to rim in zircons from the ignimbrite of Ferguson Wash indicates reheating and that zircon grew later than and at higher temperatures than quartz. The low zircon temperatures from tuff of Black Hills reveals a system that was growing quartz and zircon at the same low, nearly solidus temperatures. Reasons for its eruption are not readily apparent in the thermal history of zircon and quartz. These two systems record different thermal histories than previously studied, younger systems like the Bishop tuff, in which quartz records late reheating just prior to eruption and a system that was growing quartz later and at higher temperatures than zircon.