Formation of novel microstructures in conventionally cast Al–Fe–V–Si alloys

Sahoo, K L and Das, S K and Murty, B S (2003) Formation of novel microstructures in conventionally cast Al–Fe–V–Si alloys. Materials Science and Engineering A, 355 (1-2). pp. 193-200.

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Abstract

The present paper reports the formation of novel morphologies of intermetallic compounds during the solidification of different Al–Fe–V–Si alloys using cooling rates ranging from 1 to 20 K s−1. The influence of cooling rate, composition of the alloy and the addition of Mg and Ni–20%Mg alloy on the morphology of the intermetallic phases, particularly that of Al13Fe4 phase, is reported. Al13Fe4 forms with a ten-armed star shaped morphology with small amount of Si (<1 wt.%) at a cooling rate of ≈14 K s−1. A lower cooling rate and higher Si content result in degeneration of the ten-armed stars into other morphologies. The higher the Si content, the higher the cooling rate required to form the ten-armed star-shaped Al13Fe4 phase. Ten-fold growth morphology of the precipitates is formed due to twinning along or (1 0 0) planes. The morphology, size and distribution of those precipitates can be considerably modified by Mg treatment. Treatment of an Al–8.3Fe–0.8V–0.9Si alloy melt with 1.5 wt.% of Mg or 1 wt.% of a Ni–20Mg alloy alters the ten-armed growth morphology to rectangular, hexagonal or other compact forms.

Item Type:Article
Official URL/DOI:doi:10.1016/S0921-5093(03)00064-9
Uncontrolled Keywords:Al–Fe–V–Si alloy; Conventional casting; Solidification; Intermetallic phase; Microstructure
Divisions:Metal Extraction and Forming
ID Code:55
Deposited By:Dr. A K Sahu
Deposited On:30 Sep 2009 16:31
Last Modified:08 Feb 2012 17:02
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