{"id":{"repo_id":"brazil-ufrn","oai_identifier":"oai:repositorio.ufrn.br:123456789/23753"},"canonical_url":"https://search.dev.ndltd.org/etd/brazil-ufrn/oai:repositorio.ufrn.br:123456789/23753","repository":{"repo_id":"brazil-ufrn","name":"Brazil UFRN","base_url":"https://repositorio.ufrn.br/server/oai/request"},"display":{"title":"Avaliação tribológica de compósitos de PTFE e rejeito de scheelita aplicáveis a mancais secos","abstract":"Dry rubbing journal bearing is a structural part that is present in the most of mechanical systems of industries from home appliances, agricultural, aerospace, aeronautic and automotive sectors. This work gives continuity to a research started in Group of Studies in Tribology and Structural Integrity (GET) at Federal University of Rio Grande do Norte (UFRN) and has objective to investigate, tribologically, a scheelite tailings- filled PTFE composites to dry rubbing journal bearings application, to reduce cost and extend life service of this parts. The tailing of scheelite, obtained from scheelite mining to produce tungsten, is a mineral spoilage composed of oxides, as a silicon oxides, calcium, aluminum, iron, magnesium, tungsten and others. The tailing of scheelite was analyzed as acquired through SEM and EDS analysis, and sieved to get a particle size less than 45 μm. PTFE was analyzed through XRD. PTFE and scheelite tailings was mechanically mixed, hot compression molding in a designed mold involved by a electrical resistance and compressed by a hydraulic press. It was investigated tribological performance of composites subject to loads (1) in reciprocating movement and (2) repeated indentations. The new and tested surfaces were analyzed through Atomic Force Microscope (AFM) to collect periodic and non periodic roughness parameters. It was verified that scheelite tailing content and frequency of reciprocating influenced tribological performance and strength of composites, related to coefficient of friction, roughness, wear and indentation. The developed and tested polymeric composites showed to constitute a new materials suitable to dry rubbing journal bearings applications, notably 80% of PTFE and 20% scheelite tailing composite content that was the best tribological performance composite and being introduced as a viable alternative and lower cost than pure PTFE.","abstract_html":"Dry rubbing journal bearing is a structural part that is present in the most of mechanical systems of industries from home appliances, agricultural, aerospace, aeronautic and automotive sectors. This work gives continuity to a research started in Group of Studies in Tribology and Structural Integrity (GET) at Federal University of Rio Grande do Norte (UFRN) and has objective to investigate, tribologically, a scheelite tailings- filled PTFE composites to dry rubbing journal bearings application, to reduce cost and extend life service of this parts. The tailing of scheelite, obtained from scheelite mining to produce tungsten, is a mineral spoilage composed of oxides, as a silicon oxides, calcium, aluminum, iron, magnesium, tungsten and others. The tailing of scheelite was analyzed as acquired through SEM and EDS analysis, and sieved to get a particle size less than 45 μm. PTFE was analyzed through XRD. PTFE and scheelite tailings was mechanically mixed, hot compression molding in a designed mold involved by a electrical resistance and compressed by a hydraulic press. It was investigated tribological performance of composites subject to loads (1) in reciprocating movement and (2) repeated indentations. The new and tested surfaces were analyzed through Atomic Force Microscope (AFM) to collect periodic and non periodic roughness parameters. It was verified that scheelite tailing content and frequency of reciprocating influenced tribological performance and strength of composites, related to coefficient of friction, roughness, wear and indentation. The developed and tested polymeric composites showed to constitute a new materials suitable to dry rubbing journal bearings applications, notably 80% of PTFE and 20% scheelite tailing composite content that was the best tribological performance composite and being introduced as a viable alternative and lower cost than pure PTFE.","abstract_has_math":false,"creators":["Fernandes, Roberto Klecius Mendonça"],"institution":"Brasil","degree_name":null,"degree_level":null,"degree_discipline":null,"degree_department":null,"school":null,"contributors":[],"advisors":["Medeiros, João Telesforo Nóbrega de"],"committee_chairs":[],"committee_members":[],"year":2017,"date_issued":"2017-05-15","date_published":"2017-05-15","updated_at":"2026-07-24T01:20:54Z","subjects":["Mancal","Fretting","PTFE","Rejeito de Scheelita","Compósitos poliméricos"],"languages":["por"],"rights":["Acesso Aberto"],"rights_urls":[],"identifier_entries":[]},"links":{"outbound_url":"https://repositorio.ufrn.br/jspui/handle/123456789/23753","outbound_label":"Repository record","outbound_source":"dc:identifier.uri"},"metadata_groups":[{"id":"people","label":"People","entries":[{"key":"dc:contributor.advisor","label":"Advisor","values":["Medeiros, João Telesforo Nóbrega de"]},{"key":"dc:creator","label":"Author","values":["Fernandes, Roberto Klecius Mendonça"]}]},{"id":"academic_context","label":"Academic Context","entries":[{"key":"dc:date.accessioned","label":"Dc Date Accessioned","values":["2017-08-11T10:55:04Z"]},{"key":"dc:date.available","label":"Dc Date Available","values":["2017-08-11T10:55:04Z"]},{"key":"dc:date.issued","label":"Date","values":["2017-05-15"]},{"key":"dc:type","label":"Dc Type","values":["doctoralThesis"]}]},{"id":"subjects_keywords","label":"Subjects and Keywords","entries":[{"key":"dc:subject","label":"Dc Subject","values":["Mancal","Fretting","PTFE","Rejeito de Scheelita","Compósitos poliméricos"]}]},{"id":"language_rights","label":"Language and Rights","entries":[{"key":"dc:language","label":"Dc Language","values":["por"]},{"key":"dc:rights","label":"Dc Rights","values":["Acesso Aberto"]}]},{"id":"identifiers","label":"Identifiers","entries":[{"key":"dc:identifier.uri","label":"Identifier URI","values":["https://repositorio.ufrn.br/jspui/handle/123456789/23753"]}]},{"id":"additional","label":"Additional Metadata","entries":[{"key":"dc:description.abstract","label":"Abstract","values":["Dry rubbing journal bearing is a structural part that is present in the most of mechanical systems of industries from home appliances, agricultural, aerospace, aeronautic and automotive sectors. This work gives continuity to a research started in Group of Studies in Tribology and Structural Integrity (GET) at Federal University of Rio Grande do Norte (UFRN) and has objective to investigate, tribologically, a scheelite tailings- filled PTFE composites to dry rubbing journal bearings application, to reduce cost and extend life service of this parts. The tailing of scheelite, obtained from scheelite mining to produce tungsten, is a mineral spoilage composed of oxides, as a silicon oxides, calcium, aluminum, iron, magnesium, tungsten and others. The tailing of scheelite was analyzed as acquired through SEM and EDS analysis, and sieved to get a particle size less than 45 μm. PTFE was analyzed through XRD. PTFE and scheelite tailings was mechanically mixed, hot compression molding in a designed mold involved by a electrical resistance and compressed by a hydraulic press. It was investigated tribological performance of composites subject to loads (1) in reciprocating movement and (2) repeated indentations. The new and tested surfaces were analyzed through Atomic Force Microscope (AFM) to collect periodic and non periodic roughness parameters. It was verified that scheelite tailing content and frequency of reciprocating influenced tribological performance and strength of composites, related to coefficient of friction, roughness, wear and indentation. The developed and tested polymeric composites showed to constitute a new materials suitable to dry rubbing journal bearings applications, notably 80% of PTFE and 20% scheelite tailing composite content that was the best tribological performance composite and being introduced as a viable alternative and lower cost than pure PTFE."]},{"key":"dc:title","label":"Title","values":["Avaliação tribológica de compósitos de PTFE e rejeito de scheelita aplicáveis a mancais secos"]}]}],"canonical_facts":{"dc:contributor.advisor":["Medeiros, João Telesforo Nóbrega de"],"dc:creator":["Fernandes, Roberto Klecius Mendonça"],"dc:date.accessioned":["2017-08-11T10:55:04Z"],"dc:date.available":["2017-08-11T10:55:04Z"],"dc:date.issued":["2017-05-15"],"dc:description.abstract":["Dry rubbing journal bearing is a structural part that is present in the most of mechanical systems of industries from home appliances, agricultural, aerospace, aeronautic and automotive sectors. This work gives continuity to a research started in Group of Studies in Tribology and Structural Integrity (GET) at Federal University of Rio Grande do Norte (UFRN) and has objective to investigate, tribologically, a scheelite tailings- filled PTFE composites to dry rubbing journal bearings application, to reduce cost and extend life service of this parts. The tailing of scheelite, obtained from scheelite mining to produce tungsten, is a mineral spoilage composed of oxides, as a silicon oxides, calcium, aluminum, iron, magnesium, tungsten and others. The tailing of scheelite was analyzed as acquired through SEM and EDS analysis, and sieved to get a particle size less than 45 μm. PTFE was analyzed through XRD. PTFE and scheelite tailings was mechanically mixed, hot compression molding in a designed mold involved by a electrical resistance and compressed by a hydraulic press. It was investigated tribological performance of composites subject to loads (1) in reciprocating movement and (2) repeated indentations. The new and tested surfaces were analyzed through Atomic Force Microscope (AFM) to collect periodic and non periodic roughness parameters. It was verified that scheelite tailing content and frequency of reciprocating influenced tribological performance and strength of composites, related to coefficient of friction, roughness, wear and indentation. The developed and tested polymeric composites showed to constitute a new materials suitable to dry rubbing journal bearings applications, notably 80% of PTFE and 20% scheelite tailing composite content that was the best tribological performance composite and being introduced as a viable alternative and lower cost than pure PTFE."],"dc:identifier.uri":["https://repositorio.ufrn.br/jspui/handle/123456789/23753"],"dc:language":["por"],"dc:rights":["Acesso Aberto"],"dc:subject":["Mancal","Fretting","PTFE","Rejeito de Scheelita","Compósitos poliméricos"],"dc:title":["Avaliação tribológica de compósitos de PTFE e rejeito de scheelita aplicáveis a mancais secos"],"dc:type":["doctoralThesis"]},"updated_at":"2026-07-24T01:20:54Z"}