Estudo de um composito de matriz de aluminio reforçado copm fibras de AL/AL IND.2 O IND.3 obtido pela reação entre o aluminio e fibras silicosas

AUTOR(ES)
DATA DE PUBLICAÇÃO

2000

RESUMO

This investigation describes the research for obtaining metallic composites with fibrous ceramic reinforcement into an aluminum matrix, through the variation of the technique known as Reactive Infiltratíon. The fibers were incorporated into the aluminum matrix by using cold uniaxiai pressing or hot extruding processes of a mixture of aluminum particles and fibers. Afier producing the composites, the reactive infIltration technique was applied through thermal treatment (for the samples obtained by hot extruding) or sintering (for the samples obtained by cold uniaxial pressing) at 600 oCo By using this technique, the silica present into the fibrous compositions is forced to react with the aluminum of the matrix, causing a transformation on the fibers morphology. Their original ceramic dense compositions are replaced by a porous alumina structure, infIltrated by a liquid AI-Si composition, formed by the aluminum of the matrix and the silicon liberated by the reaction between silica and aluminum. Due to this, the original discrete interface metallceramic is eliminated and a continuous interface is generated between the materiais through the existing continuity of the infiltrated metal and the matrix itself. Fracture and mechanical tests of the samples obtained by hot extruding and thermal treated show the existence of a high interfacial bonding energy between the reinforcement and the matrix, with a significant increase on the Ultimate Tensile Strength comparing with the tests on non-treated samples. The results have shown that the method used is innovative, promising, and easy to be applied when comparing to various other known and used methods for the production of metal matrix composites, providing an effective control at the interface between aluminum and the reinforcements presenting silica in their compositions. This study, in particular, presents a contribution to the area of metallic composites through the unpublished use of non-industrialized fibrous silica reinforcements into an aluminum matrix and of preliminary investigations of the interfacial phenomenon existing between both materials

ASSUNTO(S)

silica compostos fibrosos compostos metalicos

ACESSO AO ARTIGO

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