Founding Research Journal

Founding Research Journal

Investigating the Effect of Superheat Temperature and Modification on the Columnar to Equiaxed Transition of Al-Si Eutectic Alloy

Document Type : Original Research Article

Authors
1 M.Sc., Materials and Polymer Engineering Department, Hakim Sabzevari University, Sabzevar, Iran.
2 Accociate Professor, Materials and Polymer Engineering Department, Hakim Sabzevari University, Sabzevar, Iran.
10.22034/frj.2024.445351.1193
Abstract
The properties of cast parts are influenced by their microscopic and macroscopic structures. Any changes in the structure during the solidification process can cause inhomogeneity in the properties of the casting. Among these changes, It can be pointed out the transition from columnar to equiaxed structures.This research study investigated the impact of superheat temperature and modification treatment on the transition from columnar to equiaxed growth in directionally solidified aluminum-silicon eutectic alloy. In a directional solidification system, the molten alloy was cooled from varying temperatures (590, 630, 660, and 730 oC) to room temperature. Temperature measurements were taken from six points at a certain distance from the cooling surface in order to estimate the cooling rate and calculate the temperature gradient and growth rate. The macroscopic and microscopic structures were evaluated to determine the transition zone from columnar to equiaxed grains and the change in eutectic growth morphology. The results of the study indicate that the transition from columnar to equiaxed growth occurs at a cooling rate lower than 0.13 K/s. Moreover, it was found that modifying the structure of silicon with adding 0.05 wt.% of strontiuminto the melt causes the transition from columnar to equiaxed growth to occur at a cooling rate of 0.21 K/s.
Keywords
Subjects

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Volume 8, Issue 1 - Serial Number 24
Spring and Summer
Summer 2024
Pages 5-15

  • Receive Date 09 March 2024
  • Revise Date 19 May 2024
  • Accept Date 28 May 2024