Superplasticity in a Chip-Consolidated Mg97Zn1Y2 Alloy with LPSO Phase

Conference paper
Part of the The Minerals, Metals & Materials Series book series (MMMS)


Novel Mg97Zn1Y2 alloy of equiaxed fine grains with long-period stacking ordered (LPSO) phase was prepared by consolidation of chips machined from a twin-roll-cast alloy. The chip-consolidated Mg97Zn1Y2 alloy exhibited superplasticity at a wide initial strain-rate ranging from 1 × 10−3 to 3 × 10−1 s−1 at temperatures of 623 and 673 K. The maximum elongation was approximately 560% at 3 × 10−2 s−1 at 673 K. The strain rate sensitivity index (m-values) was shown to be greater than 0.3 in this study; this value seems to be large enough to ensure uniform elongation during superplastic deformation. SEM/EBSD measurements revealed that the chip-consolidated Mg97Zn1Y2 alloy was composed of mixed equiaxed fine-grains of α-Mg and LPSO phases of a mean size of ~1 μm. The grain boundary sliding in the equiaxed fine-grains appears to account for most of the mechanism of superplastic deformation in this alloy.


Mg–Zn–Y Long-period stacking ordered phase Chip consolidation Superplasticity 



This study is supported by grants-in-aid for Scientific Research(A) No. 16H02404 and (B) No. 17H03431 from the MEXT Japan, and by the Sumitomo Electric Industries, Ltd. Endowed Chair in Kumamoto University.


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© The Minerals, Metals & Materials Society 2018

Authors and Affiliations

  1. 1.Magnesium Research Center, Department of Materials ScienceKumamoto UniversityKumamotoJapan
  2. 2.Magnesium Alloy Development DivisionSumitomo Electric Industries, Ltd.Itami-shiJapan

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