Effect of boron on the microstructure of near-eutectic Al-Si alloys

Journal Article · Wed Feb 14 23:00:00 EST 2007 · Materials Characterization

DOI:https://doi.org/10.1016/j.matchar.2006.04.009· OSTI ID:21003533

Yuying, Wu ^[1]; Xiangfa, Liu ^[1]; Xiufang, Bian ^[1]

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1. Key Laboratory of Materials Liquid Structure and Heredity, Ministry of Education, Shandong University, Jinan 250061, Shandong (China)

The effect of boron on the microstructure of a near-eutectic Al-Si alloy (ZL109) was investigated by scanning electron microscopy (SEM) and electron beam microprobe analysis (EPMA). It was found that {alpha}-Al dendrites and eutectic clusters were significantly refined by the addition of boron. Another interesting discovery is that the near-eutectic alloy exhibited hypereutectic structure characteristics when the level of boron added exceeds 0.3%, i.e., primary Si is precipitated in the eutectic microstructure. A new type of nucleation substrate for the primary Si is found, Al {sub x}Ca {sub m}B {sub n}Si. This appears to be the main reason for the precipitation of primary Si.

• OSTI ID: 21003533
• Journal Information: Materials Characterization, Journal Name: Materials Characterization Journal Issue: 2 Vol. 58; ISSN 1044-5803; ISSN MACHEX
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
ALUMINIUM ALLOYS
BORON
DENDRITES
ELECTRON BEAMS
ELECTRON MICROPROBE ANALYSIS
EUTECTICS
MICROSTRUCTURE
NUCLEATION
PRECIPITATION
SCANNING ELECTRON MICROSCOPY
SILICON
SILICON ALLOYS
SUBSTRATES