{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/41733"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/41733","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Reaction Synthesis of HfB2 in a Variety of Metallic Environments","abstract":"This project investigated the reactive formation of hafnium diboride (HfB2) in a variety of metallic environments, including blends with Bi, Cu, Ni, and Sb. HfB2 has garnered interest for a variety of applications due to its hardness, stability at elevated temperatures, as well as electrical and thermal conductivity. Experimental testing included differential scanning calorimetry (DSC) to reveal reaction initiation temperatures and enthalpies of reaction; and optical pyrometry to measure maximum reaction temperatures. Overall, DSC results indicated melting preceded reaction initiation; suggesting that the reaction initiation temperature for a certain blend occurred soon after melt formation, and could be broadly approximated by examination of binary phase diagrams. However, compositions containing bismuth ignited almost 200 ºC above the expected melting temperature. The maximum temperature measurement did not appear to correlate with reaction enthalpies as might be expected. This lack of correlation may be a result of an inability to capture the true maximum temperature due to the measurement frequency of the pyrometer, the disparity of heating rates between the two experimental methods, and/or to the influence of intermediate reactions on the temperature increase.","abstract_html":"This project investigated the reactive formation of hafnium diboride (HfB2) in a variety of metallic environments, including blends with Bi, Cu, Ni, and Sb. HfB2 has garnered interest for a variety of applications due to its hardness, stability at elevated temperatures, as well as electrical and thermal conductivity. Experimental testing included differential scanning calorimetry (DSC) to reveal reaction initiation temperatures and enthalpies of reaction; and optical pyrometry to measure maximum reaction temperatures. Overall, DSC results indicated melting preceded reaction initiation; suggesting that the reaction initiation temperature for a certain blend occurred soon after melt formation, and could be broadly approximated by examination of binary phase diagrams. However, compositions containing bismuth ignited almost 200 ºC above the expected melting temperature. The maximum temperature measurement did not appear to correlate with reaction enthalpies as might be expected. This lack of correlation may be a result of an inability to capture the true maximum temperature due to the measurement frequency of the pyrometer, the disparity of heating rates between the two experimental methods, and/or to the influence of intermediate reactions on the temperature increase.","abstract_has_math":false,"creators":["Dykema, Christopher Patrick"],"institution":"Virginia Tech","degree_name":"Master of Science","degree_level":"masters","degree_discipline":"Materials Science and Engineering","degree_department":"Materials Science and Engineering","school":null,"contributors":[],"advisors":[],"committee_chairs":["Kampe, Stephen L."],"committee_members":["Pickrell, Gary R.","Aning, Alexander O."],"year":2009,"date_issued":"2009-07-30","date_published":"2009-07-30","updated_at":"2026-07-22T22:19:31Z","subjects":["hafnium diboride","reaction synthesis"],"languages":[],"rights":["In Copyright"],"rights_urls":["http://rightsstatements.org/vocab/InC/1.0/"],"identifier_entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-03192012-142230"],"render_values":[{"text":"etd-03192012-142230","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/41733","outbound_label":"Handle","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.committeechair","label":"Committee Chair","values":["Kampe, Stephen L."]},{"key":"dc:contributor.committeemember","label":"Committee Member","values":["Pickrell, Gary R.","Aning, Alexander O."]},{"key":"dc:contributor.department","label":"Department","values":["Materials Science and Engineering"]},{"key":"dc:creator","label":"Author","values":["Dykema, Christopher Patrick"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T21:32:08Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T21:32:08Z","2012-06-15"]},{"key":"dc:date.issued","label":"Date","values":["2009-07-30"]},{"key":"dc:publisher","label":"Institution","values":["Virginia Tech"]},{"key":"dc:type","label":"Dc Type","values":["Thesis"]},{"key":"thesis:degree_discipline","label":"Discipline","values":["Materials Science and Engineering"]},{"key":"thesis:degree_level","label":"Degree Level","values":["masters"]},{"key":"thesis:degree_name","label":"Degree Name","values":["Master of Science"]},{"key":"thesis:institution_name","label":"Thesis Institution Name","values":["Virginia Polytechnic Institute and State University"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["hafnium diboride","reaction synthesis"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:rights","label":"Dc Rights","values":["In Copyright"]},{"key":"dc:rights.uri","label":"Rights URI","values":["http://rightsstatements.org/vocab/InC/1.0/"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.other","label":"Dc Identifier Other","values":["etd-03192012-142230"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/41733"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["This project investigated the reactive formation of hafnium diboride (HfB2) in a variety of metallic environments, including blends with Bi, Cu, Ni, and Sb. HfB2 has garnered interest for a variety of applications due to its hardness, stability at elevated temperatures, as well as electrical and thermal conductivity. Experimental testing included differential scanning calorimetry (DSC) to reveal reaction initiation temperatures and enthalpies of reaction; and optical pyrometry to measure maximum reaction temperatures. Overall, DSC results indicated melting preceded reaction initiation; suggesting that the reaction initiation temperature for a certain blend occurred soon after melt formation, and could be broadly approximated by examination of binary phase diagrams. However, compositions containing bismuth ignited almost 200 ºC above the expected melting temperature. The maximum temperature measurement did not appear to correlate with reaction enthalpies as might be expected. This lack of correlation may be a result of an inability to capture the true maximum temperature due to the measurement frequency of the pyrometer, the disparity of heating rates between the two experimental methods, and/or to the influence of intermediate reactions on the temperature increase."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["Reaction Synthesis of HfB2 in a Variety of Metallic Environments"]}]}],"canonical_facts":{"dc:contributor.committeechair":["Kampe, Stephen L."],"dc:contributor.committeemember":["Pickrell, Gary R.","Aning, Alexander O."],"dc:contributor.department":["Materials Science and Engineering"],"dc:creator":["Dykema, Christopher Patrick"],"dc:date.accessioned":["2014-03-14T21:32:08Z"],"dc:date.available":["2014-03-14T21:32:08Z","2012-06-15"],"dc:date.issued":["2009-07-30"],"dc:description.abstract":["This project investigated the reactive formation of hafnium diboride (HfB2) in a variety of metallic environments, including blends with Bi, Cu, Ni, and Sb. HfB2 has garnered interest for a variety of applications due to its hardness, stability at elevated temperatures, as well as electrical and thermal conductivity. Experimental testing included differential scanning calorimetry (DSC) to reveal reaction initiation temperatures and enthalpies of reaction; and optical pyrometry to measure maximum reaction temperatures. Overall, DSC results indicated melting preceded reaction initiation; suggesting that the reaction initiation temperature for a certain blend occurred soon after melt formation, and could be broadly approximated by examination of binary phase diagrams. However, compositions containing bismuth ignited almost 200 ºC above the expected melting temperature. The maximum temperature measurement did not appear to correlate with reaction enthalpies as might be expected. This lack of correlation may be a result of an inability to capture the true maximum temperature due to the measurement frequency of the pyrometer, the disparity of heating rates between the two experimental methods, and/or to the influence of intermediate reactions on the temperature increase."],"dc:description.degree":["Master of Science"],"dc:identifier.other":["etd-03192012-142230"],"dc:identifier.uri":["http://hdl.handle.net/10919/41733"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["hafnium diboride","reaction synthesis"],"dc:title":["Reaction Synthesis of HfB2 in a Variety of Metallic Environments"],"dc:type":["Thesis"],"thesis:degree_discipline":["Materials Science and Engineering"],"thesis:degree_level":["masters"],"thesis:degree_name":["Master of Science"],"thesis:institution_name":["Virginia Polytechnic Institute and State University"]},"updated_at":"2026-07-22T22:19:31Z"}