{"id":{"repo_id":"vt","oai_identifier":"oai:vtechworks.lib.vt.edu:10919/35927"},"canonical_url":"https://search.dev.ndltd.org/etd/vt/oai:vtechworks.lib.vt.edu:10919/35927","repository":{"repo_id":"vt","name":"Virginia Tech","base_url":"https://vtechworks.lib.vt.edu/oai/request"},"display":{"title":"Fabrication And Damping Behavior Of Particulate BaTiO3 Ceramic Reinforced Copper Matrix Composites","abstract":"Metal matrix composites offer unique opportunities for achieving multi-functionality in materials. In an attempt to investigate the possibility of enhancing damping characteristics of structural metals, copper was reinforced with tetragonal ferroelectric BaTiO3 particulates (Cu-BaTiO3 composites) using powder metallurgy techniques. The effect of particulate size and three processing conditions, sintering atmosphere, cooling rate and, uniaxial compaction pressure on the tetragonality and hence the ferroelectric properties of barium titanate powder were investigated using differential scanning calorimetry (DSC) and x-ray diffraction (XRD). The results show that sintering atmosphere and cooling rates have little effect on the tetragonality of barium titanate powder. Tetragonality of barium titanate powder decreased gradually with decreasing particle size. The decrease in tetragonality with decreasing particle size, however, was only severe in the very fine powders. Although no direct relationship was found between uniaxial compaction pressure and tetragonality, uniaxial pressure may also decrease the tetragonality of barium titanate. Three Cu-BaTiO3 composites, D1, D2 and D3 reinforced with 40vol% barium titanate particles of average sizes 209μm, 66μm and 2μm were respectively fabricated. The retention of the ferroelectric tetragonal phase of barium titanate after composite processing was confirmed by DSC. Composite microstructures observed using optical and scanning electron microscopy revealed uniform dispersions of barium titanate particles in D1 and D2. In D3, the barium titanate formed a chain-like structure because of extensive agglomeration of the fine reinforcement particles. Damping characteristics of the composites were evaluated between 25oC and 165oC at a frequency of 1Hz using dynamic mechanical analysis (DMA). The relative damping capacities (tanδ) in the composites were higher than the unreinforced metal. The damping capacity of composites D1 and D2 was also found to be dependent on temperature. Damping capacity was high from room temperature up to the Curie point of barium titanate, after which there was a slight drop in damping values probably due to a loss in ferroelectric properties. The small drop in damping values recorded in excess of the Curie temperature is an indication that ferroelectricity contributes little to the overall damping capacity of the Cu-BaTiO3 composites. This results from either a reduced ferroelectric damping in barium titanate particles or, poor stress transfer from matrix to reinforcement because of the weak and porous copper-barium titanate interface.","abstract_html":"Metal matrix composites offer unique opportunities for achieving multi-functionality in materials. In an attempt to investigate the possibility of enhancing damping characteristics of structural metals, copper was reinforced with tetragonal ferroelectric BaTiO3 particulates (Cu-BaTiO3 composites) using powder metallurgy techniques. The effect of particulate size and three processing conditions, sintering atmosphere, cooling rate and, uniaxial compaction pressure on the tetragonality and hence the ferroelectric properties of barium titanate powder were investigated using differential scanning calorimetry (DSC) and x-ray diffraction (XRD). The results show that sintering atmosphere and cooling rates have little effect on the tetragonality of barium titanate powder. Tetragonality of barium titanate powder decreased gradually with decreasing particle size. The decrease in tetragonality with decreasing particle size, however, was only severe in the very fine powders. Although no direct relationship was found between uniaxial compaction pressure and tetragonality, uniaxial pressure may also decrease the tetragonality of barium titanate. Three Cu-BaTiO3 composites, D1, D2 and D3 reinforced with 40vol% barium titanate particles of average sizes 209μm, 66μm and 2μm were respectively fabricated. The retention of the ferroelectric tetragonal phase of barium titanate after composite processing was confirmed by DSC. Composite microstructures observed using optical and scanning electron microscopy revealed uniform dispersions of barium titanate particles in D1 and D2. In D3, the barium titanate formed a chain-like structure because of extensive agglomeration of the fine reinforcement particles. Damping characteristics of the composites were evaluated between 25oC and 165oC at a frequency of 1Hz using dynamic mechanical analysis (DMA). The relative damping capacities (tanδ) in the composites were higher than the unreinforced metal. The damping capacity of composites D1 and D2 was also found to be dependent on temperature. Damping capacity was high from room temperature up to the Curie point of barium titanate, after which there was a slight drop in damping values probably due to a loss in ferroelectric properties. The small drop in damping values recorded in excess of the Curie temperature is an indication that ferroelectricity contributes little to the overall damping capacity of the Cu-BaTiO3 composites. This results from either a reduced ferroelectric damping in barium titanate particles or, poor stress transfer from matrix to reinforcement because of the weak and porous copper-barium titanate interface.","abstract_has_math":false,"creators":["Asare, Ted Ankomahene"],"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":2004,"date_issued":"2004-11-19","date_published":"2004-11-19","updated_at":"2026-07-22T22:20:29Z","subjects":["Barium titanate","Ferroelectricity","Damping capacity","Metal matrix composites"],"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-12032004-141136"],"render_values":[{"text":"etd-12032004-141136","href":null,"code":true}]}]},"links":{"outbound_url":"http://hdl.handle.net/10919/35927","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":["Asare, Ted Ankomahene"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2014-03-14T20:48:49Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2014-03-14T20:48:49Z","2004-12-06"]},{"key":"dc:date.issued","label":"Date","values":["2004-11-19"]},{"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":["Barium titanate","Ferroelectricity","Damping capacity","Metal matrix composites"]}]},{"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-12032004-141136"]},{"key":"dc:identifier.uri","label":"Identifier URI","values":["http://hdl.handle.net/10919/35927"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Metal matrix composites offer unique opportunities for achieving multi-functionality in materials. In an attempt to investigate the possibility of enhancing damping characteristics of structural metals, copper was reinforced with tetragonal ferroelectric BaTiO3 particulates (Cu-BaTiO3 composites) using powder metallurgy techniques. The effect of particulate size and three processing conditions, sintering atmosphere, cooling rate and, uniaxial compaction pressure on the tetragonality and hence the ferroelectric properties of barium titanate powder were investigated using differential scanning calorimetry (DSC) and x-ray diffraction (XRD). The results show that sintering atmosphere and cooling rates have little effect on the tetragonality of barium titanate powder. Tetragonality of barium titanate powder decreased gradually with decreasing particle size. The decrease in tetragonality with decreasing particle size, however, was only severe in the very fine powders. Although no direct relationship was found between uniaxial compaction pressure and tetragonality, uniaxial pressure may also decrease the tetragonality of barium titanate. Three Cu-BaTiO3 composites, D1, D2 and D3 reinforced with 40vol% barium titanate particles of average sizes 209μm, 66μm and 2μm were respectively fabricated. The retention of the ferroelectric tetragonal phase of barium titanate after composite processing was confirmed by DSC. Composite microstructures observed using optical and scanning electron microscopy revealed uniform dispersions of barium titanate particles in D1 and D2. In D3, the barium titanate formed a chain-like structure because of extensive agglomeration of the fine reinforcement particles. Damping characteristics of the composites were evaluated between 25oC and 165oC at a frequency of 1Hz using dynamic mechanical analysis (DMA). The relative damping capacities (tanδ) in the composites were higher than the unreinforced metal. The damping capacity of composites D1 and D2 was also found to be dependent on temperature. Damping capacity was high from room temperature up to the Curie point of barium titanate, after which there was a slight drop in damping values probably due to a loss in ferroelectric properties. The small drop in damping values recorded in excess of the Curie temperature is an indication that ferroelectricity contributes little to the overall damping capacity of the Cu-BaTiO3 composites. This results from either a reduced ferroelectric damping in barium titanate particles or, poor stress transfer from matrix to reinforcement because of the weak and porous copper-barium titanate interface."]},{"key":"dc:description.degree","label":"Dc Description Degree","values":["Master of Science"]},{"key":"dc:title","label":"Title","values":["Fabrication And Damping Behavior Of Particulate BaTiO3 Ceramic Reinforced Copper Matrix Composites"]}]}],"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":["Asare, Ted Ankomahene"],"dc:date.accessioned":["2014-03-14T20:48:49Z"],"dc:date.available":["2014-03-14T20:48:49Z","2004-12-06"],"dc:date.issued":["2004-11-19"],"dc:description.abstract":["Metal matrix composites offer unique opportunities for achieving multi-functionality in materials. In an attempt to investigate the possibility of enhancing damping characteristics of structural metals, copper was reinforced with tetragonal ferroelectric BaTiO3 particulates (Cu-BaTiO3 composites) using powder metallurgy techniques. The effect of particulate size and three processing conditions, sintering atmosphere, cooling rate and, uniaxial compaction pressure on the tetragonality and hence the ferroelectric properties of barium titanate powder were investigated using differential scanning calorimetry (DSC) and x-ray diffraction (XRD). The results show that sintering atmosphere and cooling rates have little effect on the tetragonality of barium titanate powder. Tetragonality of barium titanate powder decreased gradually with decreasing particle size. The decrease in tetragonality with decreasing particle size, however, was only severe in the very fine powders. Although no direct relationship was found between uniaxial compaction pressure and tetragonality, uniaxial pressure may also decrease the tetragonality of barium titanate. Three Cu-BaTiO3 composites, D1, D2 and D3 reinforced with 40vol% barium titanate particles of average sizes 209μm, 66μm and 2μm were respectively fabricated. The retention of the ferroelectric tetragonal phase of barium titanate after composite processing was confirmed by DSC. Composite microstructures observed using optical and scanning electron microscopy revealed uniform dispersions of barium titanate particles in D1 and D2. In D3, the barium titanate formed a chain-like structure because of extensive agglomeration of the fine reinforcement particles. Damping characteristics of the composites were evaluated between 25oC and 165oC at a frequency of 1Hz using dynamic mechanical analysis (DMA). The relative damping capacities (tanδ) in the composites were higher than the unreinforced metal. The damping capacity of composites D1 and D2 was also found to be dependent on temperature. Damping capacity was high from room temperature up to the Curie point of barium titanate, after which there was a slight drop in damping values probably due to a loss in ferroelectric properties. The small drop in damping values recorded in excess of the Curie temperature is an indication that ferroelectricity contributes little to the overall damping capacity of the Cu-BaTiO3 composites. This results from either a reduced ferroelectric damping in barium titanate particles or, poor stress transfer from matrix to reinforcement because of the weak and porous copper-barium titanate interface."],"dc:description.degree":["Master of Science"],"dc:identifier.other":["etd-12032004-141136"],"dc:identifier.uri":["http://hdl.handle.net/10919/35927"],"dc:publisher":["Virginia Tech"],"dc:rights":["In Copyright"],"dc:rights.uri":["http://rightsstatements.org/vocab/InC/1.0/"],"dc:subject":["Barium titanate","Ferroelectricity","Damping capacity","Metal matrix composites"],"dc:title":["Fabrication And Damping Behavior Of Particulate BaTiO3 Ceramic Reinforced Copper Matrix Composites"],"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":"2026-07-22T22:20:29Z"}