Effect of Sn Addition on Superplastic Properties of Zn-22mass%Al Eutectoid Alloy

Abstract:

Superplastic behavior of a Zn 22 mass % Al eutectoid alloy (SPZ) with small addition of Sn (SPZSn) was investigated. Granular grain size of about 0.3 μm was obtained by water quench after annealing SPZ and SPZ05Sn (addition of 0.05 mass % Sn into the SPZ) at 653 K for 2 h. The fundamental microstructure of the SPZ05Sn was similar to that of the SPZ, but, microstructure observation by STEM showed additive Sn was present at the α’ grain boundary in the SPZ05Sn. Excellent high strain rate superplasticity was achieved in the SPZ05Sn, with elongation of more than 1300 % at 523 K at strain rate of 10^-1 S^-1. Furthermore, large elongation of about 1100 % was recorded at 473 K at strain rate of 10^-1 S^-1. The large elongation and high strain rate sensitivity value of the SPZ05Sn tend to shift to higher strain rate region as compared to those of the SPZ. It was considered that the small addition of Sn into the SPZ effectively suppressed the grain growth of α and β phase during the superplastic deformation, because granular grains less than 2 μm is maintained after superplastic deformation at 523 K.

• Periodical: Materials Science Forum (Volumes 838-839)
• Pages: 518-522
• DOI: https://doi.org/10.4028/www.scientific.net/MSF.838-839.518
• Online since: January 2016
• Authors: Takaomi Itoi*, Fumiyasu Sato, Yuki Takabayashi, Mitsuji Hirohashi
• Keywords: High-Strainrate Superplasticity, Microstructure, SPZ

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