Microstructural evolution and mechanical properties of rheocast Al-7.1WT%Si alloy

Authors

  • Mehdi Raeissia
  • Behzad Niroumandb

DOI:

https://doi.org/10.30544/230

Keywords:

Semisolid rheocasting, particle density, Dendrite arm detachment, Ripening model, Tensile strength.

Abstract

Effects of Semi-Solid Rheocasting (SSR) process on the structure and mechanical properties of Al-7.1wt%Si alloy were studied. The results showed that the non-dendritic structure could be formed by a short stirring period below liquidus temperature provided that stirring was combined with localized rapid heat extraction from the melt. The effect was examined by calculation of the time needed for detachment of dendrite arms at the initial stages of solidification and was associated with a large particle density in the rheocast slurry. Samples processed in semisolid state had lower porosity, higher tensile strength and higher elongation than that processed in fully-liquid state. The SSR- processed sample had a lower tensile strength but a higher elongation than the sample cooled without localized cooling and stirring. It was suggested that the lower strength of SSR-processed alloy was related to the inability of the α-particles to restrain crack propagation through the brittle eutectic matrix.

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Published

2016-09-07

How to Cite

Raeissia, Mehdi, and Behzad Niroumandb. 2016. “Microstructural Evolution and Mechanical Properties of Rheocast Al-7.1WT%Si Alloy”. Metallurgical and Materials Engineering 22 (3):155-64. https://doi.org/10.30544/230.

Issue

Vol. 22 No. 3 (2016)

Section

Articles - archived

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Copyright (c) 2016 Mehdi Raeissia, Behzad Niroumandb

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