Compression of Micro-pillars of a Long Period Stacking Ordered Phase in the Mg-Zn-Y system

2013 ◽  
Vol 1516 ◽  
pp. 151-156 ◽  
Author(s):  
Atsushi Inoue ◽  
Kyosuke Kishida ◽  
Haruyuki Inui ◽  
Koji Hagihara
Keyword(s):  
Basal Plane ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Deformation Bands ◽  
Axis Orientation ◽  
Lpso Phase ◽  
Long Period ◽  
Image Position ◽  
Micro Pillars ◽  
Loading Axis

ABSTRACTDeformation behavior of an 18R-type long period stacking ordered (LPSO) phase in the Mg-Zn-Y system was studied by micro-pillar compressions of single crystalline specimens prepared by focused ion beam (FIB) technique as a function of loading axis orientation and specimen dimensions. When the loading axis is inclined to the basal plane of the LPSO phase by 42°, basal slip of (0001)<11$\bar 2$0>-type is activated irrespective of the specimen dimensions. When the loading axis is parallel to the basal plane, the formation of thick deformation bands are observed for all specimens tested. Strong size-dependence of yield stress values is observed for both types of micro-pillar specimens with different loading axis orientations.

scholarly journals COMPRESSION OF ECAPED TITANIUM MICRO-PILLARS FOR TWO PRINCIPAL ORIENTATIONS

2020 ◽  
Vol 27 ◽  
pp. 1-5
Author(s):  
David Vokoun ◽  
Jan Maňák ◽  
Karel Tesař ◽  
Stanislav Habr
Keyword(s):  
Room Temperature ◽  
Focused Ion Beam ◽  
Mechanical Response ◽  
Thermomechanical Processing ◽  
Ion Beam ◽  
Orientation Dependence ◽  
Material Strength ◽  
Angular Pressing ◽  
Macro Scale ◽  
Micro Pillars

The thermomechanical processing by equal-channel angular pressing (ECAP) is used for certain metals and alloys in order to make their structure fine and to increase material strength. In the previous study done at our institute, grade 2 titanium was successfully processed using four consecutive route A passes via a 90 ° ECAP die with high backpressure at room temperature. Orientation dependence of compressive and tensile loading of ECAPed titanium samples was demonstrated at macro-scale. However, scarce attention has been paid so far to the mechanical behavior of ECAPed titanium samples at micro-scale. In the present study, compression experiments on titanium micropillars, fabricated using focused ion beam, are carried out for two main directions in respect to preceding ECAP pressing (insert and extrusion directions). The purpose of this study is to discuss the orientation dependence of mechanical response during compression of the as-ECAPed titanium micro-pillars.

scholarly journals Anisotropic Plastic Behavior in an Extruded Long-Period Ordered Structure Mg90Y6.5Ni3.5 (at.%) Alloy

Crystals ◽  
2020 ◽  
Vol 10 (4) ◽  
pp. 279
Author(s):  
Gerardo Garces ◽  
Rafael Barea ◽  
Andreas Stark ◽  
Norbert Schell
Keyword(s):  
Basal Plane ◽  
Extrusion Direction ◽  
Plastic Behavior ◽  
Ordered Structure ◽  
Lpso Phase ◽  
Long Period ◽  
Anisotropic Plastic ◽  
The Difference ◽  
Internal Strains

The Mg90Y6.5Ni3.5 alloy composed almost completely of the Long-Period-Stacking-Ordered (LPSO) phase has been prepared by casting and extrusion at high temperature. An elongated microstructure is obtained where the LPSO phase with 18R crystal structure is oriented with its basal plane parallel to the extrusion direction. Islands of α-magnesium are located between the LPSO grains. The mechanical properties of the alloy are highly anisotropic and depend on the stress sign as well as the relative orientation between the stress and the extrusion axes. The alloy is stronger when it is compressed along the extrusion direction. Under this configuration, the slip of <a> dislocations in the basal plane is highly limited. However, the activation of kinking induces an increase in the plastic deformation. In the transversal extrusion direction, some grains deform by the activation of basal slip. The difference in the yield stress between the different stress configurations decreases with the increase in the test temperature. The evolution of internal strains obtained during in-situ compressive experiments reveals that tensile twinning is not activated in the LPSO phase.

Compression of Micropillars of TiAl Coexisting with Ti3Al

2011 ◽  
Vol 1295 ◽  
Author(s):  
Kazuki Fujimura ◽  
Kyosuke Kishida ◽  
Katsushi Tanaka ◽  
Haruyuki Inui
Keyword(s):  
Single Crystals ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Testing Machine ◽  
Compression Tests ◽  
Micro Hardness ◽  
Hardness Testing ◽  
Selective Activation ◽  
Deformation Modes ◽  
Loading Axis

ABSTRACTSquare-shaped micropillar of nearly stoichiometric TiAl single crystals with various loading axis orientations were prepared from TiAl PST crystals by focused ion beam (FIB) technique and deformed in compression using a micro hardness testing machine equipped with a flat diamond tip in order to investigate the values of CRSS for the three types of operative deformation modes, namely ${111}1/2&#x003C; 1 \bar 10 &#x003E;$ ordinary slip, ${111}&#x003C; \bar 101 &#x003E;$ superlattice slip and ${111}&#x003C;11\bar 2 &#x003E;$ twinning. The selective activation of the three types of deformation modes was confirmed to be achieved by compression tests of $[\bar 2 11]-, \bar 110- and [\bar 2 12]$-oriented single crystalline micropillars, respectively. The average CRSS values for ordinary slip, superlattice slip and deformation twinning obtained for micropillars with an initial side length between 3.8 and 7.9μm were estimated to be about 145, 284 and 113 MPa, respectively.

Nanostructuring the graphite basal plane by focused ion beam patterning and oxygen etching

2006 ◽  
Vol 17 (23) ◽  
pp. 5889-5894 ◽  
Author(s):  
Artur Böttcher ◽  
Moritz Heil ◽  
Ninette Stürzl ◽  
Stefan S Jester ◽  
Sharali Malik ◽  
...  
Keyword(s):  
Basal Plane ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Graphite Basal Plane ◽  
Ion Beam Patterning ◽  
Oxygen Etching

Compression of Single-Crystal Micropillars of the ζ Intermetallic Phase in the Fe-Zn System

2012 ◽  
Vol 1516 ◽  
pp. 157-162 ◽  
Author(s):  
Masahiro Inomoto ◽  
Norihiko L. Okamoto ◽  
Haruyuki Inui
Keyword(s):  
Single Crystal ◽  
Room Temperature ◽  
Focused Ion Beam ◽  
Ion Beam ◽  
Deformation Behaviour ◽  
Intermetallic Phase ◽  
Compression Tests ◽  
Slip Direction ◽  
Beam Method ◽  
Image Position

ABSTRACTThe deformation behaviour of the ζ (zeta) phase in the Fe-Zn system has been investigated via room-temperature compression tests of single-crystal micropillar specimens prepared by the focused ion beam method. Trace analysis of slip lines indicates that {110} slip occurs for the specimens investigated in the present study. Although the slip direction has not been uniquely determined, comparison of Schmid factors and yield stress values suggests that the slip direction might be <1$\overline 1 $2>, which is inconsistent with the easiest slip system {110}[001] predicted on the basis of the primitive Peierls-Nabarro model.

Crystal Structures of Long-Period Stacking-Ordered Phases in the Mg-TM-RE Ternary Systems

2013 ◽  
Vol 1516 ◽  
pp. 291-302 ◽  
Author(s):  
Kyosuke Kishida ◽  
Hideyuki Yokobayashi ◽  
Atsushi Inoue ◽  
Haruyuki Inui
Keyword(s):  
Crystal Structures ◽  
Hexagonal Lattice ◽  
Ternary Systems ◽  
Dark Field ◽  
Lattice Points ◽  
Atomic Arrangement ◽  
Lpso Phase ◽  
Long Period ◽  
The Difference ◽  
Image Position

ABSTRACTCrystal structures of long-period stacking-ordered (LPSO) phases in the Mg-TM (transition-metal)-RE(rare-earth) systems were investigated by atomic resolution high-angle annular dark-field scanning transmission electron microscopy (HAADF-STEM). The 18R-type LPSO phase is constructed by stacking 6-layer structural blocks, each of which contains four consecutive close-packed planes enriched with TM and RE atoms. Formation of the TM6RE8 clusters with the L12 type atomic arrangement is commonly observed in both Mg-Al-Gd and Mg-Zn-Y LPSO phases. The difference between the crystal structures of Mg-Al-Gd and Mg-Zn-Y LPSO phases can be interpreted as the difference in the in-plane ordering of the TM6RE8 clusters in the structural block. The Mg-Al-Gd LPSO phase exhibits a long-range in-plane ordering of Gd and Al, which can be described by the periodic arrangement of the Al6Gd8 clusters with the L12 type atomic arrangement on lattice points of a two-dimensional 2$\sqrt 3 $aMg × 2$\sqrt 3 $aMg primitive hexagonal lattice, although the LPSO phase in the Zn/Y-poor Mg-Zn-Y alloys exhibits a shortrange in-plane ordering of the Zn6Y8 clusters.

scholarly journals Advances in 3D focused ion beam tomography

MRS Bulletin ◽  
2014 ◽  
Vol 39 (4) ◽  
pp. 354-360 ◽  
Author(s):  
Marco Cantoni ◽  
Lorenz Holzer
Keyword(s):  
Focused Ion Beam ◽  
Ion Beam ◽  
Image Position ◽  
Focused Ion Beam Tomography

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