{"id":{"repo_id":"uiuc","oai_identifier":"oai:www.ideals.illinois.edu:2142/82888"},"canonical_url":"https://search.dev.ndltd.org/etd/uiuc/oai:www.ideals.illinois.edu:2142/82888","repository":{"repo_id":"uiuc","name":"University of Illinois - Urbana-Champaign","base_url":"https://www.ideals.illinois.edu/oai-pmh"},"display":{"title":"Synthesis, Consolidation, and Mechanical Testing of Nanophase Metals","abstract":"Indentation creep experiments were performed on nanocrystalline copper and palladium specimens and also on sinterforged Ti-48Al specimens. The copper and palladium specimens showed a higher creep rate than their microcrystalline counterparts, exhibiting creep even at room temperature. The activation energies for both specimens are lower than activation energy for grain boundary diffusion in microcrystalline materials. A model is proposed to explain the higher creep rate. It assumes that the specimens produced from vapor condensed powders have a higher grain boundary energy due to a higher disorder in their grain boundary structure. Contrary to the pure metal specimens, the sinterforged Ti-48Al specimens exhibited an activation energy close to that for lattice diffusion in the microcrystalline alloy and also the activation energy determined from the sinterforging experiments.","abstract_html":"Indentation creep experiments were performed on nanocrystalline copper and palladium specimens and also on sinterforged Ti-48Al specimens. The copper and palladium specimens showed a higher creep rate than their microcrystalline counterparts, exhibiting creep even at room temperature. The activation energies for both specimens are lower than activation energy for grain boundary diffusion in microcrystalline materials. A model is proposed to explain the higher creep rate. It assumes that the specimens produced from vapor condensed powders have a higher grain boundary energy due to a higher disorder in their grain boundary structure. Contrary to the pure metal specimens, the sinterforged Ti-48Al specimens exhibited an activation energy close to that for lattice diffusion in the microcrystalline alloy and also the activation energy determined from the sinterforging experiments.","abstract_has_math":false,"creators":["Kim, Lisa Sungwoon"],"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":["Averback, R.S."],"advisors":[],"committee_chairs":[],"committee_members":[],"year":2015,"date_issued":"2015-09-25T20:53:29Z","date_published":"2015-09-25T20:53:29Z","updated_at":"2026-07-22T22:26:20Z","subjects":["Engineering, Metallurgy"],"languages":["eng"],"rights":[],"rights_urls":[],"identifier_entries":[{"key":"dc:identifier","label":"Identifier","values":["(MiAaPQ)AAI9812654"],"render_values":[{"text":"(MiAaPQ)AAI9812654","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/2142/82888","outbound_label":"Handle","outbound_source":"dc:identifier"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor","label":"Contributor","values":["Averback, R.S."]},{"key":"dc:creator","label":"Author","values":["Kim, Lisa Sungwoon"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date","label":"Dc Date","values":["2015-09-25T20:53:29Z","10000-01-01","1997"]},{"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, Metallurgy"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["eng"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier","label":"Identifier","values":["http://hdl.handle.net/2142/82888","(MiAaPQ)AAI9812654"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description","label":"Description","values":["Indentation creep experiments were performed on nanocrystalline copper and palladium specimens and also on sinterforged Ti-48Al specimens. The copper and palladium specimens showed a higher creep rate than their microcrystalline counterparts, exhibiting creep even at room temperature. The activation energies for both specimens are lower than activation energy for grain boundary diffusion in microcrystalline materials. A model is proposed to explain the higher creep rate. It assumes that the specimens produced from vapor condensed powders have a higher grain boundary energy due to a higher disorder in their grain boundary structure. Contrary to the pure metal specimens, the sinterforged Ti-48Al specimens exhibited an activation energy close to that for lattice diffusion in the microcrystalline alloy and also the activation energy determined from the sinterforging experiments.","Made available in DSpace on 2015-09-25T20:53:29Z (GMT). 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The copper and palladium specimens showed a higher creep rate than their microcrystalline counterparts, exhibiting creep even at room temperature. The activation energies for both specimens are lower than activation energy for grain boundary diffusion in microcrystalline materials. A model is proposed to explain the higher creep rate. It assumes that the specimens produced from vapor condensed powders have a higher grain boundary energy due to a higher disorder in their grain boundary structure. Contrary to the pure metal specimens, the sinterforged Ti-48Al specimens exhibited an activation energy close to that for lattice diffusion in the microcrystalline alloy and also the activation energy determined from the sinterforging experiments.","Made available in DSpace on 2015-09-25T20:53:29Z (GMT). No. of bitstreams: 2 license.txt: 4848 bytes, checksum: 96035ab3f5e1c23cc7138a224ce498bd (MD5) 9812654.pdf: 4173706 bytes, checksum: 74002eede5241f30a83dc5e620f9a937 (MD5) Previous issue date: 1997","Embargo set by: Seth Robbins for item 84169 Lift date: Forever Reason: Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","Restricted to the U of I community idenfinitely during batch ingest of legacy ETDs","U of I Only","142 p.","Thesis (Ph.D.)--University of Illinois at Urbana-Champaign, 1997."],"dc:identifier":["http://hdl.handle.net/2142/82888","(MiAaPQ)AAI9812654"],"dc:language":["eng"],"dc:subject":["Engineering, Metallurgy"],"dc:title":["Synthesis, Consolidation, and Mechanical Testing of Nanophase Metals"],"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":"2026-07-22T22:26:20Z"}