Research on Microstructure and Growth Mechanism of Different Primary Silicon in Hypereutectic Aluminum Alloy

The as-cast microstructure of a typical hypereutectic Al-25Si alloy was studied, and the growth mechanism of different primary silicon phases was analyzed. The results show that the as-cast microstructure phase composition of the alloy is mainly primary silicon and eutectic silicon. Primary silicon...

Full description

Saved in:
Bibliographic Details
Published in:Journal of physics. Conference series 2022-01, Vol.2152 (1), p.12022
Main Authors: Zhao, Gaozhan, Xing, Zhihui, Li, Ming, Gao, Shiqing, Tao, Jianquan, Chai, Shuxin
Format: Article
Language:English
Subjects:
Al-Si Alloy
Aluminum base alloys
Crystal defects
Grooves
Growth Mechanism
Hypereutectic
Mechanical properties
Microstructure
Phase composition
Physics
Pistons
Primary Silicon
Properties
Silicon
Twin Grooves
Citations: Items that this one cites
Items that cite this one
Online Access:Get full text
Tags: Add Tag
No Tags, Be the first to tag this record!
Description
Summary:The as-cast microstructure of a typical hypereutectic Al-25Si alloy was studied, and the growth mechanism of different primary silicon phases was analyzed. The results show that the as-cast microstructure phase composition of the alloy is mainly primary silicon and eutectic silicon. Primary silicon is mainly petal-like, massive and other complex polyhedrons, and there are a lot of cavities, cracks and other defects in the interior and boundary; Eutectic silicon is coarse and long needle-like, and the distribution is relatively messy, which seriously deteriorates the mechanical properties and cutting performance, and hinders the further application of the alloy in the field of lightweight pistons. Petal-shaped primary silicon is grown by combining five tetrahedral crystal nuclei in the melt into a decahedron, while bulk primary silicon is mainly caused by the unbalanced aggregation of impurity elements. And these two types of silicon phase growth methods are related to the twin groove growth mechanism, which is the result of a combination of multiple mechanisms.
ISSN:1742-6588
1742-6596
DOI:10.1088/1742-6596/2152/1/012022