Effect of Pr Modification Treatment on the Microstructure and Mechanical Properties of Cast Al-Mg₂Si Metal Matrix Composite

Abstract:

The effect of different concentrations of Pr on the microstructure and tensile properties of cast Al-18 wt.%Mg₂Si in situ metal matrix composite was investigated. The results show that the addition of proper amount of Pr has significant modification effect on primary Mg₂Si in the Al-18 wt.% Mg₂Si composite. With the increase of Pr content from 0.1 to 0.7%, the morphology of primary Mg₂Si is changed from irregular or dendritic to polyhedral shape, and its average particle size is significantly decreased from 65 to 17 μm. When the Pr content exceeds 1.0%, the primary Mg₂Si become coarse again. Tensile tests reveal that the Pr addition improves the tensile strength and ductility of the material. Comparing with those of unmodified composite, the ultimate tensile strength and percentage elongation with 0.7% Pr are increased by 36.5% and 161.6%, respectively.

• Periodical: Advanced Materials Research (Volume 936)
• Pages: 23-27
• DOI: https://doi.org/10.4028/www.scientific.net/AMR.936.23
• Online since: June 2014
• Authors: Yi Si*
• Keywords: Al/Mg₂Si Composites, Casting, Microstructure, Pr Addition, Tensile Properties

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