O presente trabalho foi motivado pela necessidade de minimizar impactos ambientais causados pela extraÃÃo de granito, dando aplicabilidade aos rejeitos da indÃstria de rochas ornamentais. Trabalhos anteriores mostraram a viabilidade de se utilizar esses rejeitos na produÃÃo de guia-fios cerÃmicos para a IndÃstria TÃxtil. Um outro componente, bastante utilizado na IndÃstria TÃxtil à o funil de saÃda da fiaÃÃo a rotor. O elevado custo de importaÃÃo desses componentes torna bastante atrativo a busca de materiais alternativos para sua fabricaÃÃo no PaÃs. AnÃlises preliminares mostraram que esses funis sÃo compostos basicamente de alumina, com resistÃncia mecÃnica muito superior ao dos resÃduos de granito que se pretendia utilizar, levando à necessidade de se reforÃar o material. PartÃculas de alumina foram incorporadas Ãs amostras formando compÃsitos dos quais foram estudadas diversas composiÃÃes de matriz e reforÃo para se obter caracterÃsticas aproximadas daquelas dos funis comerciais. Foram realizadas analises de caracterizaÃÃo dos materiais envolvidos, e ensaios para determinaÃÃo das propriedades fÃsicas. As amostras com 30% e 40% em peso do reforÃo de alumina resultaram em uma melhor sinterizaÃÃo e resultados de dureza com 81% dos valores obtidos pelos funis comerciais, com uma rugosidade prÃxima da exibida por aqueles componentes / The present work was motivated by the need to minimize environmental impacts caused by granite quarrying. One of the ways to achieve this objective is to find value-added technical applications for granite residues. In a previous work it has been demonstrated that these silica-rich granite powders can be employed as raw-materials for the production of textile thread-guides. One very promising application for the textile industry in Brazil is the fabrication of open end navels. These are high-cost components made from expensive technical ceramics, which are imported from Europe. Therefore, it would be very interesting to be able to produce them at a lower cost, using residual granite powders. Preliminary analysis of the materials of commercially available textile navels has shown that they are composed mainly of alumina. Under normal conditions, alumina-made components exhibit much higher mechanical strength and hardness than silica-made components. Thus, it is necessary to introduce reinforcements to the starting granite powder used in this work (a residue obtained form the commercial stone âRosa Iracemaâ), in order to improve the performance of the parts made from it. Different amounts of submicrometric alumina particles were added to the starting powder, rendering composites. These composites were submitted to several mechanical and physical analysis aiming at finding the best combination of properties, compared to the properties of the commercially available textile navels. Test pieces containing 30% and 40%wt alumina gave the best results in terms of sinterability, and surface roughness. Their hardness was approximately 80% of the hardness of the alumina navels
| Identifer | oai:union.ndltd.org:IBICT/oai:www.teses.ufc.br:2596 |
| Date | 25 May 2009 |
| Creators | Candido Jorge de Sousa Lobo |
| Contributors | Ricardo EmÃlio Ferreira Quevedo Nogueira, Divanira Ferreira Maia, Josà de AraÃjo Nogueira Neto |
| Publisher | Universidade Federal do CearÃ, Programa de PÃs-GraduaÃÃo em Engenharia e CiÃncia de Materiais, UFC, BR |
| Source Sets | IBICT Brazilian ETDs |
| Language | Portuguese |
| Detected Language | English |
| Type | info:eu-repo/semantics/publishedVersion, info:eu-repo/semantics/masterThesis |
| Format | application/pdf |
| Source | reponame:Biblioteca Digital de Teses e Dissertações da UFC, instname:Universidade Federal do Ceará, instacron:UFC |
| Rights | info:eu-repo/semantics/openAccess |
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