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Effects of Sr and B addition on microstructure and mechanical properties of AZ91 magnesium alloy

Published online by Cambridge University Press:  31 January 2011

H.L. Zhao*
Affiliation:
College of Materials Science & Engineering, Zhengzhou University, Zhengzhou 450002, People’s Republic of China
S.K. Guan
Affiliation:
College of Materials Science & Engineering, Zhengzhou University, Zhengzhou 450002, People’s Republic of China
F.Y. Zheng
Affiliation:
College of Materials Science & Engineering, Zhengzhou University, Zhengzhou 450002, People’s Republic of China
*
a)Address all correspondence to this author. e-mail: [email protected]
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Abstract

The effects of Sr and B addition on the microstructure and mechanical properties of AZ91 alloy were studied. The results of this work show that a small amount of Sr addition to AZ91 refined the grain size. The highest tensile strength was obtained from the alloy with the optimal composition of 0.5% Sr and 0.09% B added, in which the average grain size was 42 μm. The tensile strength and elongation of the AZ91–0.5%Sr–0.09%B alloy were 151 MPa and 1.62%, respectively. Some needle-shaped Al4Sr particles distributed mainly at grain boundaries have been observed in the alloys with Sr and B additions. The fluidity is improved significantly, and the solidification range decreased by adding Sr and B. The liquidus of AZ91 alloy decreased markedly with the addition of Sr and B, but the solidus hardly changed. Therefore, the solidification range can be decreased, which will improve the die-casting properties.

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Articles
Copyright
Copyright © Materials Research Society 2007

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References

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