Effect of Ga Addition on Morphology and Recovery of Primary Si During Al–Si Alloy Solidification Refining

Abstract

The effect of Ga addition on alloy macrostructure, morphology and recovery rate of primary Si during the Al–Si–Ga alloy solvent refining process of silicon was studied in this work. The addition of Ga to Al–Si alloy could change the morphology of the primary Si. The average plate thickness of the primary Si increases with increase of Ga content. With the increase of Ga content, the average plate length of the primary Si crystals becomes larger when the Ga content is less than 5% in the Al–30%Si–xGa alloy, but becomes smaller when the Ga content exceeds 5%. Al–Si–Ga alloys consist of three types, primary Si, GaxAl1–x, (α-Al+Si+β-Ga) eutectic. (111) is the preferred growth surface of the plate-like primary Si. The recovery rate of the primary Si increases with the increase of Ga content. When the Ga content increased to 20% in Al–30%Si–xGa alloy, the relative recovery rate of the primary Si increased to 50.41% than that in Al–30%Si alloy.

Keywords

• al–si–ga alloy
• gallium addition
• size distribution
• primary si
• recovery rate
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