Detalhes bibliográficos
Ano de defesa: |
2015 |
Autor(a) principal: |
Ribeiro, Bruno de Rosso
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Orientador(a): |
Santos, Carlos Alexandre dos
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Banca de defesa: |
Não Informado pela instituição |
Tipo de documento: |
Dissertação
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Tipo de acesso: |
Acesso aberto |
Idioma: |
por |
Instituição de defesa: |
Pontifícia Universidade Católica do Rio Grande do Sul
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Programa de Pós-Graduação: |
Programa de Pós-Graduação em Engenharia e Tecnologia de Materiais
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Departamento: |
Faculdade de Engenharia
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País: |
Brasil
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Palavras-chave em Português: |
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Área do conhecimento CNPq: |
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Link de acesso: |
http://tede2.pucrs.br/tede2/handle/tede/6348
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Resumo: |
The main objective of this work was to analyze the solutioning and artificial aging heat treatments of aluminum-copper casting alloys, composed of two distinctive copper contents: 2.5% and 3.5%, unidirectionally solidified in an instrumented metal-mold system. Solidification parameters such as solidification velocities, thermal gradients and cooling rates were determined from cooling curves obtained by thermal analysis. Macrostructures and microstructures of ingots were analyzed in relation to parameters such as columnar-equiaxed transition (CET) and the secondary dendrite arm spacing (SDAS). The heat treatments were performed in order to better understand the solutioning and artificial aging processes of copper in the aluminum matrix. The results concerning to the solidification parameters have permitted to obtain expressions for solidification velocities, thermal gradient and cooling rates as a function of examined alloys. Relationship among solidification conditions, structural formation and hardness were also obtained [SDAS=f(TRL); HB=f(SDAS)]. The Al-3.5wt%Cu alloy has show smaller dendritic arm spacing (10%), higher columnar zone (12%), higher hardness in the as-cast condition (8%), as well as better response to the heat treatments than the examined Al-2.5wt%Cu. |