Study of porosity and identification in A356 alloy. / Estudo sobre a incidência das porosidades e sua identificação em uma liga de alumínio A356.

AUTOR(ES)
DATA DE PUBLICAÇÃO

2007

RESUMO

The objective of this work is to study the type of defect identified during the pressure tightness test of aluminum parts and to establish a relationship between porosity level of an A356 aluminum alloy and the production processes, hydrogen level, feeding system, and directional solidification. Different nitrogen blowing times, inversion of the mould pattern, relative to the partition line, changing of the feeding system dimensions, replacement of the lateral feeding by exothermic gloves and the use of chills where tested. Ceramic filters were also tested, in order to evaluate their influence on the formation of porosities and on the porosity level, through a decrease of turbulence and an increase in the capacity of retaining non-metallic inclusions and part of the oxide films. Casting was performed by the green sand process using different ceramic filters. The obtained parts were metallographicaly analyzed through optical and scanning electronic microscopy using also EDS analysis. The results showed that porosity is related with the feeding conditions and directional solidification besides the hydrogen content of the alloys.

ASSUNTO(S)

hydrogen a356 aluminum alloy liga de alumínio a356 chills porosity ceramic filters feeding systems porosidade (identificação) oxide films

ACESSO AO ARTIGO

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