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Previous issue date: 2014-08-22 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / A efetiva utiliza??o dos recursos naturais diante o acelerado crescimento econ?mico resulta no aumento cont?nuo de res?duos industriais, e para suprimir estes res?duos, um processo de reciclagem ? de prefer?ncia uma solu??o atraente. Durante a usinagem dos blocos de zirc?nia para diversos tipos de implantes odontol?gicos, grande parte do material ? desprendida na forma de p?, que posteriormente ? descartado. A zirc?nia tetragonal estabilizada com 3% em mol de ?tria (Y-TZP) possui uma variedade de aplica??es na ?rea de engenharia e biom?dica devido ? sua ?tima combina??o de resist?ncia, tenacidade ? fratura, condutividade i?nica e baixa condutividade t?rmica. Al?m do dano para o meio ambiente, o desperd?cio deste material resulta em preju?zo financeiro, refletindo em elevado custo final no tratamento para os pacientes. Os materiais de partida utilizados neste trabalho foram dois diferentes p?s do sistema cer?mico ZrO3-Y2O3: zirc?nia comercial nanoparticulada e res?duo de zirc?nia microparticulado. Os p?s foram conformados por prensagem uniaxial e isost?tica e em seguida sinterizadas a 1500, 1550 e 1600 ?C, durante 1 hora. As t?cnicas de granulometria a laser, difra??o de raios X (DRX), e dilatometria foram utilizadas para caracteriza??o do p?. Ap?s sinterizados, foram realizados ensaios de densidade e porosidade, difra??o de raios X (DRX), resist?ncia mec?nica ? flex?o, microdureza Vickers e an?lise de tenacidade ? fratura, e microscopia eletr?nica de varredura (MEV). As amostras compactadas via prensagem isost?tica apresentaram valores de porosidade inferiores a 0,78% e demostraram maior efetividade de compacta??o comparada ? via uniaxial. Foi observado nos difratogramas de raios X, com o aumento da temperatura, a intensidade dos picos da fase monocl?nica diminuiu. A temperatura de sinteriza??o influenciou de forma moderada a microdureza das amostras, demostrando pequenos acr?scimos da dureza at? a temperatura de 1600?C. A resist?ncia ? flex?o do res?duo de zirc?nia aumenta com o aumento da temperatura de sinteriza??o, para ambas as vias de compacta??o, apresentando melhores valores por via isost?tica. / The actual use of natural resources on accelerated economic growth, resulting in continuous increase of industrial waste, and to remove these residues, a recycling process is preferably na attractive solution. During the machining of blocks of zirconia to several types of dental implants, most of the material is loosened as a powder, which is subsequently discarded. The stabilized tetragonal zirconia with 3% yttria (Y-TZP) mol boasts a variety of applications in engineering, and biomedical, because of its great combination of strength, fracture toughness, ionic conductivity and low thermal conductivity. Besides the damage to the environment wasting of the material resulting in financial loss, reflecting the high final cost of medical treatment for patients. The starting materials used in this work were two different powders ZrO3-Y2O3ceramic system: commercial zirconia nanoparticulate and microparticulate zirc?nia residue. The powder was uniaxially and isostatically pressed and then sintered at 1500, 1550 and 1600 ? C for 1 hour. The techniques of laser granulometry, X-ray diffraction (XRD) and dilatometry were used for powder characterization. After sintering were performed density and porosity tests, X-ray diffraction (XRD), Flexural strength, microhardness and fracture toughness analysis, and scanning electron microscopy (SEM). Samples compacted via isostatic pressing showed values less than 0.78% porosity and demonstrated greater effectiveness compared to uniaxial compression. Was observed in X-ray diffra
ction, that with increasing temperature, the intensity of the peaks of monoclinic phase is decreased. The sintering temperature moderately has influenced on the microhardness of samples, showing small increases in hardness to temperature of 1600 ? C. The flexural strength of zirconia residue increases with increasing sintering temperature for both routes of compression, showing the best values for isostatic compression.
| Identifer | oai:union.ndltd.org:IBICT/oai:repositorio.ufrn.br:123456789/20433 |
| Date | 22 August 2014 |
| Creators | Silva, Larissa Bezerra da |
| Contributors | 50580396720, http://lattes.cnpq.br/5460040602567184, Ramalho, Eduardo Galv?o, 03605359418, http://lattes.cnpq.br/3006037569302325, Silva, Vamberto Monteiro da, 67456863415, http://lattes.cnpq.br/7962325767490100, Acchar, Wilson |
| Publisher | Universidade Federal do Rio Grande do Norte, PROGRAMA DE P?S-GRADUA??O EM CI?NCIA E ENGENHARIA DE MATERIAIS, UFRN, Brasil |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | Portuguese |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Source | reponame:Repositório Institucional da UFRN, instname:Universidade Federal do Rio Grande do Norte, instacron:UFRN |
| Rights | info:eu-repo/semantics/openAccess |
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