Ingeniería, investigación y tecnología
Print version ISSN 1405-7743
MARTINEZ-DELGADO, E.J.; ORTEGA DE LA ROSA, R.; CISNEROS-GUERRERO, M.A. and HARO-RODRIGUEZ, S.. Effect of NaCL Upon an AI-Si Casting Alloy Hipoeutec. Ing. invest. y tecnol. [online]. 2009, vol.10, n.4, pp. 331-342. ISSN 1405-7743.
This work, comprehends the study about the effect of NaCl kind Halite upon the morphology of eutectic Silicon and porosity in a cast hipoeutectic Al-Si alloy. The melting was carried out in two furnaces, the first to combustion ofLPgas in graphite crucible to increase the content of Si in the alloy from 0.13 to 5% wt using metallic silicon with a purity of 99.35% wt, and the second of electric resistances in the same kind of crucible to control the temperature at 750° C. The melting material was casting into molds of sand shell. To add the salt into the metallic bath, two techniques were used; one with injection by means of Argon gas and the other one by gravity, in both cases three quantities of salt were used, 0.5, 1.5 and 2.5% wt respectively, powdered and preheated at 150° C during 60 min. The obtained samples were analyzed metallographily evidencing the modification of the eutectic Si, presenting the best results the samples with 1.5 & 2.5% wt of salt added by gravity. Too was obtained effect of Salt upon the degassing of bath metallic, where the simples with 1.5% wt presented the best results. Finally, by means of Scanning Electron Microscopy, the precipitates present were characterized in the samples.
Keywords : Aluminium; porosity; modification; sodium; solidification; AI-Si alloy.