Interflake spacings and undercoolings in Al-Si irregular eutectic alloy


Gunduz M., Kaya H., Cadirli E., Ozmen A.

MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING, vol.369, pp.215-229, 2004 (Journal Indexed in SCI) identifier identifier

  • Publication Type: Article / Article
  • Volume: 369
  • Publication Date: 2004
  • Doi Number: 10.1016/j.msea.2003.11.020
  • Title of Journal : MATERIALS SCIENCE AND ENGINEERING A-STRUCTURAL MATERIALS PROPERTIES MICROSTRUCTURE AND PROCESSING
  • Page Numbers: pp.215-229
  • Keywords: Al-Si eutectic alloy, directional solidification, microstructure, operating parameters, uridercooling, TEMPERATURE-GRADIENT, GROWTH VELOCITY, SILICON ALLOYS, FE-C, SOLIDIFICATION, MICROSTRUCTURE, LAMELLAR, BINARY

Abstract

Aluminium-silicon irregular eutectic alloy was melted in a graphite crucible in vacuum. This alloy was directionally solidified at a constant growth rate, V (8.3 mum/s) and at different temperature gradients, G (2.0-7.8 K/mm) and also with a constant G (7.8 K/mm) and different V (8.3-498.7 mum/s) in the Bridgman type directional solidification furnace. The interflake spacings, lambda(i), were measured from both transverse and longitudinal sections of the specimens. The relationships between interflake spacings, lambda(i) and solidification parameters V and G were obtained by linear regression analysis method. The variations of interflake spacings, lambda(i) with V, G and undercoolings, DeltaT(i), were investigated and the relationships between them were examined. Operating parameters phi and eta which reflect the spacing adjustment mechanism were obtained. lambda(i)(2)V, lambda(i) DeltaT(i), DeltaT(i)V(-a), lambda(i)(3)G and DeltaT(i)G(-b) values were determined by using lambda(i), V, G and DeltaT(i), values. The results obtained in this work have been compared with the eutectic theory and previous experimental results. (C) 2003 Elsevier B.V. All rights reserved.