{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/22955"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/22955","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Phases, microstructures, and microchemistry of silicon carbide-based ceramics","abstract":"Pure SiC. Transparent, translucent and opaque regions of high purity bulk SiC grown by chemical vapor deposition (CVD) were characterized for physical properties as well as for microstructure and chemical purity to correlate the degree of optical transparency with other material characteristics. A good correlation was obtained between SiC IR transmission and its microstructure. The transparent material was characterized by pure, essentially defect-free, $\\beta$-SiC (cubic) grains was highly oriented, with a $\\langle 111\\rangle$ direction parallel to the deposition surface. The translucent material of various colors was mostly cubic in structure but contained large amounts of twins. Opaque CVD SiC was randomly oriented, and contained one directional disorder with hexagonal ($\\alpha$-SiC) symmetry in the majority of grains and high density of dislocations elsewhere.","abstract_html":"Pure SiC. Transparent, translucent and opaque regions of high purity bulk SiC grown by chemical vapor deposition (CVD) were characterized for physical properties as well as for microstructure and chemical purity to correlate the degree of optical transparency with other material characteristics. A good correlation was obtained between SiC IR transmission and its microstructure. The transparent material was characterized by pure, essentially defect-free, <span class=\"etd-inline-math\">&beta;</span>-SiC (cubic) grains was highly oriented, with a $\\langle 111\\rangle$ direction parallel to the deposition surface. The translucent material of various colors was mostly cubic in structure but contained large amounts of twins. Opaque CVD SiC was randomly oriented, and contained one directional disorder with hexagonal (<span class=\"etd-inline-math\">&alpha;</span>-SiC) symmetry in the majority of grains and high density of dislocations elsewhere.","abstract_has_math":true,"creators":["Kim, Yongil"],"institution":"University of Illinois at Urbana-Champaign","degree_name":"Ph.D.","degree_level":"Dissertation","degree_discipline":"Materials Science and Engineering","degree_department":null,"school":null,"contributors":["Zangvil, Avigdor"],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2011,"date_issued":"2011-05-07T13:57:07Z","date_published":"2011-05-07T13:57:07Z","updated_at":"2026-07-22T22:25:21Z","subjects":["Engineering, Materials Science"],"languages":["eng"],"rights":["Copyright 1994 Kim, Yongil"],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9512428","(UMI)AAI9512428"],"render_values":[{"text":"AAI9512428","href":null,"code":true},{"text":"(UMI)AAI9512428","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/22955","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Zangvil, Avigdor"]},{"key":"dc:creator","label":"Author","values":["Kim, Yongil"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2011-05-07T13:57:07Z","10000-01-01","1994"]},{"key":"dc:type","label":"Dc Type","values":["text"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Materials Science and Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["Dissertation"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Ph.D."]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["University of Illinois at Urbana-Champaign"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Engineering, Materials Science"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]},{"key":"dc:rights","label":"Dc Rights","values":["Copyright 1994 Kim, Yongil"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["AAI9512428","(UMI)AAI9512428","http://hdl.handle.net/2142/22955"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Pure SiC. Transparent, translucent and opaque regions of high purity bulk SiC grown by chemical vapor deposition (CVD) were characterized for physical properties as well as for microstructure and chemical purity to correlate the degree of optical transparency with other material characteristics. A good correlation was obtained between SiC IR transmission and its microstructure. The transparent material was characterized by pure, essentially defect-free, $\\beta$-SiC (cubic) grains was highly oriented, with a $\\langle 111\\rangle$ direction parallel to the deposition surface. The translucent material of various colors was mostly cubic in structure but contained large amounts of twins. Opaque CVD SiC was randomly oriented, and contained one directional disorder with hexagonal ($\\alpha$-SiC) symmetry in the majority of grains and high density of dislocations elsewhere.","The SiC-AlN system. Formation of solid solutions and their stability have been investigated. Early stages of transformation from the cubic phase were determined. Thin stacking fault lamellae developed first, followed by formation of twin bands, enhanced by the presence of ALN. Hexagonal ($\\alpha$) polytypes with AlN in solid solution formed, with transitional ordered or disordered regions at the transformation interface. The diffusion mechanism in the SiC-AlN system was investigated, finding (1) Strong coupling of Al-N and Si-C pairs in the diffusion process and Diffusion Rate of SiC in AlN $>$ Diffusion Rate of AlN in SiC; (2) Neutron diffusion study indicated that Si and C atoms are replaced with Al and N atoms receptively; (3) AlN solubility in SiC is proportional to hexagonality; (4) AlN is located only at the hexagonal-type SiC layer in SiC-AlN polytypes.","SiC-matrix composites. The effects of microstructural parameters on toughness of SiC matrix composite with TiC particles have been investigated. Fracture toughness increased considerably by addition of TiC particles to SiC. The principal mechanisms for toughening in the SiC-TiC system were found to be crack deflection and crack bridging, with a possible contribution from microcracking. Microchemical analysis revealed limited mutual solubilities of TiC and SiC: the solubility of SiC in TiC. TiC did not have an effect on SiC phase stability.","Made available in DSpace on 2011-05-07T13:57:07Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9512428.pdf: 6041417 bytes, checksum: 927a64c2548e18b13a7d3a05d4cdd774 (MD5) Previous issue date: 1994","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T15:01:10Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:29:00-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"]},{"key":"dc:title","label":"Title","values":["Phases, microstructures, and microchemistry of silicon carbide-based ceramics"]}]}],"canonical_facts":{"dc:contributor":["Zangvil, Avigdor"],"dc:creator":["Kim, Yongil"],"dc:date":["2011-05-07T13:57:07Z","10000-01-01","1994"],"dc:description":["Pure SiC. Transparent, translucent and opaque regions of high purity bulk SiC grown by chemical vapor deposition (CVD) were characterized for physical properties as well as for microstructure and chemical purity to correlate the degree of optical transparency with other material characteristics. A good correlation was obtained between SiC IR transmission and its microstructure. The transparent material was characterized by pure, essentially defect-free, $\\beta$-SiC (cubic) grains was highly oriented, with a $\\langle 111\\rangle$ direction parallel to the deposition surface. The translucent material of various colors was mostly cubic in structure but contained large amounts of twins. Opaque CVD SiC was randomly oriented, and contained one directional disorder with hexagonal ($\\alpha$-SiC) symmetry in the majority of grains and high density of dislocations elsewhere.","The SiC-AlN system. Formation of solid solutions and their stability have been investigated. Early stages of transformation from the cubic phase were determined. Thin stacking fault lamellae developed first, followed by formation of twin bands, enhanced by the presence of ALN. Hexagonal ($\\alpha$) polytypes with AlN in solid solution formed, with transitional ordered or disordered regions at the transformation interface. The diffusion mechanism in the SiC-AlN system was investigated, finding (1) Strong coupling of Al-N and Si-C pairs in the diffusion process and Diffusion Rate of SiC in AlN $>$ Diffusion Rate of AlN in SiC; (2) Neutron diffusion study indicated that Si and C atoms are replaced with Al and N atoms receptively; (3) AlN solubility in SiC is proportional to hexagonality; (4) AlN is located only at the hexagonal-type SiC layer in SiC-AlN polytypes.","SiC-matrix composites. The effects of microstructural parameters on toughness of SiC matrix composite with TiC particles have been investigated. Fracture toughness increased considerably by addition of TiC particles to SiC. The principal mechanisms for toughening in the SiC-TiC system were found to be crack deflection and crack bridging, with a possible contribution from microcracking. Microchemical analysis revealed limited mutual solubilities of TiC and SiC: the solubility of SiC in TiC. TiC did not have an effect on SiC phase stability.","Made available in DSpace on 2011-05-07T13:57:07Z (GMT). No. of bitstreams: 2 license.txt: 4922 bytes, checksum: 910b249b4beec47e7ab768910c8f966f (MD5) 9512428.pdf: 6041417 bytes, checksum: 927a64c2548e18b13a7d3a05d4cdd774 (MD5) Previous issue date: 1994","Item marked as restricted to the 'UIUC Users [automated]' Group (id=2) by Howard Ding (hding2@illinois.edu) on 2011-05-07T15:01:10Z Item is restricted indefinitely.","Restriction data tranferred 2014-07-01T11:29:00-05:00 Original Data Group with Access UIUC Users [automated] Release Date: none Reason: ETDs are only available to UIUC Users without author permission","ETDs are only available to UIUC Users without author permission","U of I Only"],"dc:identifier":["AAI9512428","(UMI)AAI9512428","http://hdl.handle.net/2142/22955"],"dc:language":["eng"],"dc:rights":["Copyright 1994 Kim, Yongil"],"dc:subject":["Engineering, Materials Science"],"dc:title":["Phases, microstructures, and microchemistry of silicon carbide-based ceramics"],"dc:type":["text"],"thesis:degree_discipline":["Materials Science and Engineering"],"thesis:degree_level":["Dissertation"],"thesis:degree_name":["Ph.D."],"thesis:institution_name":["University of Illinois at Urbana-Champaign"]},"updated_at":"2026-07-22T22:25:21Z"}