Influência do tratamento térmico e do tipo de reforço nas propriedades de compósitos a base de ligas de alumínio obtidos via metalurgia do pó.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The development of composite materials is a result of the need to conjugate the properties of two or more components in one, thus maximizing the individual properties. The Aluminium Matrix Composites (AMCs) reinforced with hard particles have bulked the sectors of application due to the properties as low density and increased wear resistance. The technique of Powder Metallurgy followed by hot extrusion provides positive results in the consolidation of compacted samples, avoiding the segregation phenomena typical of casting processes. For the present work two aluminum alloys were used as matrix, AA2124 and AA6061, reinforced with silicon nitrite, titanium nitrite and titanium aluminide. Influences of the type of reinforcement, morphology of the powders and two different heat treatments, namely, T1 and T6 were studied. Some mechanical properties were evaluated as hardness, ultimate tensile strength and tribological properties. The aim of the present work is the attainment of metal matrix composites with an aluminum matrix through powder metallurgy and hot extrusion. The results have shown a homogeneous distribution of reinforcement particles on the composite materials. The ultimate tensile strength and the hardness presented a reduction in the composites when compared with the material without reinforcement, except of those reinforced with silicon nitrite wherein the bond between the matrix and the reinforcement is enhanced. The heat treatment T6 increased the mechanical properties in the materials without reinforcement and the composites of matrix AA6061, when compared with the T1. The coefficient of friction for all the studied materials was kept at about 0.4, a common value for aluminum alloys. The reinforcement particle addition showed to be efficient in the improvement of the wear resistance of all the composites in relation to the material without reinforcement.

ASSUNTO(S)

compósito de matriz metálica alumínio desgaste. engenharia de materiais e metalurgica metalurgia do pó tratamento térmico

ACESSO AO ARTIGO

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