Submitted by Automa??o e Estat?stica (sst@bczm.ufrn.br) on 2017-11-01T21:11:49Z No. of bitstreams: 1 JulianoAugustoMedeirosDeMenezesEOliveira_DISSERT.pdf: 8358330 bytes, checksum: a0ec67f844a5bacdf6c24e821ebe74d1 (MD5) / Approved for entry into archive by Arlan Eloi Leite Silva (eloihistoriador@yahoo.com.br) on 2017-11-07T19:34:30Z (GMT) No. of bitstreams: 1 JulianoAugustoMedeirosDeMenezesEOliveira_DISSERT.pdf: 8358330 bytes, checksum: a0ec67f844a5bacdf6c24e821ebe74d1 (MD5) / Made available in DSpace on 2017-11-07T19:34:31Z (GMT). No. of bitstreams: 1 JulianoAugustoMedeirosDeMenezesEOliveira_DISSERT.pdf: 8358330 bytes, checksum: a0ec67f844a5bacdf6c24e821ebe74d1 (MD5) Previous issue date: 2017-08-25 / Coordena??o de Aperfei?oamento de Pessoal de N?vel Superior (CAPES) / As ligas de alum?nio na composi??o eut?tica apresentam como caracter?stica baixa temperatura de fus?o e uma microestrutura complexa formada por constituintes eut?ticos. Elas podem ser aplicadas na ind?stria de fundi??o, por apresentarem adicionalmente alta fluidez e baixa tend?ncia ? forma??o de porosidade e de trincamento a quente. Foram produzidas por fundi??o em areia as ligas eut?ticas do sistema Al-Cu (bin?ria), Al-Cu-Si e Al-Cu-Mg (tern?rias) e Al- Cu-Si-Mg (quatern?ria). As ligas foram analisadas microestruturalmente no estado bruto de fus?o e no estado ap?s tratamento t?rmico de homogeneiza??o ? 495 ?C por at? 24 horas, via Fluoresc?ncia de Raios-X (FRX), Difra??o de Raios-X (DRX) e Microscopia Eletr?nica de Varredura (MEV) com sistema de Energia Dispersiva de Varredura (EDS). Os resultados mostraram a forma??o das principais fases constituintes no estado de equil?brio termodin?mico, a forma??o significativa de constituintes eut?ticos e a forma??o em pequena quantidade de intermet?licos Al5FeSi (plaquetas) e AlFeSiMgCu (escrita chinesa), comumente encontradas devido ? presen?a intr?nseca do ferro como impureza em ligas de alum?nio. / The aluminum alloys in the eutectic composition have a characteristic low melting temperature and a complex microstructure formed by eutectic constituents. They can be applied in the foundry industry, as they additionally present high fluidity and low tendency to the formation of porosity and hot cracking. The Al-Cu (binary), Al-Cu-Si and Al-Cu-Mg (ternary) and Al- Cu-Si-Mg (quaternary) systems were produced by sand casting. The alloys were analyzed microstructurally in the as-cast condition and after homogenizing heat treatment at 495 ? C for until 24 hours, via x-rays fluorescence (FRX), x-rays diffraction (XRD) and scanning electron microscopy (SEM) with dispersive scanning energy system (EDS). The results showed the formation of the main constituent phases in the thermodynamic equilibrium state, the significant formation of eutectic constituents and the formation of a small amount of intermetallic Al5FeSi (platelets) and AlFeSiMgCu (chinese writing), commonly found due to the intrinsic presence of iron as an impurity In aluminum alloys.