Relation between sample size and deformation mechanism in Mg-Zn-Y 18R-LPSO single crystals

With the long-period stacking ordered (LPSO) second phase, the promising mechanical properties of the Mg-Zn-Y alloys have been demonstrated. Because the LPSO phase plays an important role in strengthening mechanisms and it has the unique 18R crystal structure, it is interesting to clarify the deform...

Full description

Saved in:
Bibliographic Details
Published in:Intermetallics 2017-12, Vol.91, p.110-119
Main Authors: Chuang, W.S., Hsieh, C.H., Huang, J.C., Lin, P.H., Takagi, K., Mine, Y., Takashima, K.
Format: Article
Language:English
Subjects:
Compression tests
Crystal structure
Deformation effects
Deformation mechanism
Deformation mechanisms
Dislocations
Kinking
LPSO
Magnesium base alloys
Mechanical properties
Mg alloy
Micro-pillar
Plastic deformation
Probability
Sample size
Single crystals
Size effect
Size effects
Slip
Studies
Yttrium
Zinc base alloys
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:With the long-period stacking ordered (LPSO) second phase, the promising mechanical properties of the Mg-Zn-Y alloys have been demonstrated. Because the LPSO phase plays an important role in strengthening mechanisms and it has the unique 18R crystal structure, it is interesting to clarify the deformation mechanism and size effect associated with this particular phase. In this study, uniaxial compression tests are conducted on LPSO along [112¯0] with different sample sizes. An apparent sample size effect is observed and the plastic deformation behavior of LPSO is found to change from kink to slip when sample size is reduced to a level about 1.8 μm in diameter. The non-basal prismatic slip system is found to operate within the smaller sized micro-pillars, different from the deformation kinking observed in larger sized samples. The probability of forming stair rod dislocations associated with the sample size effect is an important key to explain this change of plastic deformation behavior. It implies that the origin of deformation kink is non-basal prismatic slip. [Display omitted] •The sample size effects in Mg-Zn-Y 18R-LPSO single crystals are examined.•The deformation mechanisms in mini, micro, and nano scales are compared.•The sample size effect is rationalized in terms of deformation mechanisms.
ISSN:0966-9795
1879-0216
DOI:10.1016/j.intermet.2017.08.009