Title:
Solution-based synthesis and processing of nanocrystalline ZrB₂-based composites
Solution-based synthesis and processing of nanocrystalline ZrB₂-based composites
dc.contributor.advisor | Speyer, Robert F. | |
dc.contributor.advisor | Sanders, Thomas H., Jr. | |
dc.contributor.author | Xie, Yanli | en_US |
dc.contributor.committeeMember | Gerhardt, Rosario | |
dc.contributor.committeeMember | Sandhage, Kenneth | |
dc.contributor.committeeMember | Snyder, Robert | |
dc.contributor.committeeMember | Zhang, John | |
dc.contributor.department | Materials Science and Engineering | en_US |
dc.date.accessioned | 2009-01-22T15:53:00Z | |
dc.date.available | 2009-01-22T15:53:00Z | |
dc.date.issued | 2008-11-24 | en_US |
dc.description.abstract | Zirconium- and tantalum-based diborides, and diboride/carbide composites are of interest for ultra-high temperature applications requiring improved thermomechanical and thermochemical stability. This thesis focuses on the synthesis, processing and sintering of nanocrystalline powders with Zr- and Ta-based diboride/carbide/silicide compositions. A solution-based processing method was developed to prepare reactive mixtures that were precursors for ZrB₂-based powders. The precursors reacted to form the ceramic powders after suitable pyrolysis and borothermal/carbothermal reduction heat treatments. Single-phase ZrB₂ powders were prepared with initial composition of C/Zr = 4.8 and B/Zr = 3.0. ZrB₂-based composite powders with ZrC, ZrO₂, TaB₂, TaC, SiC, TaSi₂ and B₄C were prepared with particle sizes of 10-500 nm for different phases based SEM micrographs. The composite powders were highly sinterable with proper processing methods developed to avoid and remove oxide impurities. The relative densities of ZrB₂/B₄C, ZrB₂/TaB₂, ZrB₂/TaB₂/B4C, ZrB₂/TaSi₂ were in the range of 91%-97% after pressureless sintering at 2020 ℃ for 1 h or 30 min. | en_US |
dc.description.degree | Ph.D. | en_US |
dc.identifier.uri | http://hdl.handle.net/1853/26640 | |
dc.publisher | Georgia Institute of Technology | en_US |
dc.subject | Sol-gel | en_US |
dc.subject | Nanocystalline | en_US |
dc.subject | Synthesis | en_US |
dc.subject | Zirconium boride | en_US |
dc.subject.lcsh | Nanocrystals Synthesis | |
dc.subject.lcsh | Zirconium | |
dc.subject.lcsh | Tantalum | |
dc.subject.lcsh | Exterme environments | |
dc.title | Solution-based synthesis and processing of nanocrystalline ZrB₂-based composites | en_US |
dc.type | Text | |
dc.type.genre | Dissertation | |
dspace.entity.type | Publication | |
local.contributor.advisor | Speyer, Robert F. | |
local.contributor.corporatename | School of Materials Science and Engineering | |
local.contributor.corporatename | College of Engineering | |
relation.isAdvisorOfPublication | ca7f4d7a-1308-47c2-8dd0-67775f5e3d5a | |
relation.isOrgUnitOfPublication | 21b5a45b-0b8a-4b69-a36b-6556f8426a35 | |
relation.isOrgUnitOfPublication | 7c022d60-21d5-497c-b552-95e489a06569 |
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