Paper

Effect of Melt Thermal Treatment on Eutectic Silicon Particles Characteristics in Cast Al-Si-Mg Alloys


Authors:
S.A. Al Kahtani
Abstract
A new means of obtaining fine Si particles is through the use of a melt thermal treatment (MTT), where the mixing of low and high temperature alloy melts produces a fine Si structure. Modification is achieved by nuclei resulting from the degeneration of large atom clusters and some refractory solids in the low temperature melt when it is heated by the high temperature melt. This is a relatively recent technique which demonstrates promise as an alternative to Sr-modification, as it requires no element addition, thus reducing the risk of increased porosity normally associated with the addition of strontium to the melt. The use of melt superheat is also found to produce refinement of the eutectic Si structure. In this case, the high melt temperature assists in the degeneration of atom clusters, providing more nuclei for α-Al dendrite formation, and a resulting refinement of the microstructure.
Keywords
Melt Thermal Treatment; Melt Superheat; Sr Modification Eutectic Si Particle Characteristics
StartPage
144
EndPage
153
Doi
10.5963/AMSA0204003
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