scholarly journals Size-induced twinning in InSb semiconductor during room temperature deformation

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Florent Mignerot ◽  
Bouzid Kedjar ◽  
Hadi Bahsoun ◽  
Ludovic Thilly
Keyword(s):  
Strain Rate ◽  
Deformation Mechanism ◽  
Room Temperature ◽  
Activation Volume ◽  
Ion Beam ◽  
Temperature Deformation ◽  
Small Scale ◽  
Shockley Partial ◽  
Partial Dislocations ◽  
Micro Pillars

AbstractRoom-temperature deformation mechanism of InSb micro-pillars has been investigated via a multi-scale experimental approach, where micro-pillars of 2 µm and 5 µm in diameter were first fabricated by focused ion beam (FIB) milling and in situ deformed in the FIB-SEM by micro-compression using a nano-indenter equipped with a flat tip. Strain rate jumps have been performed to determine the strain rate sensitivity coefficient and the related activation volume. The activation volume is found to be of the order of 3–5 b3, considering that plasticity is mediated by Shockley partial dislocations. Transmission electron microscopy (TEM) thin foils were extracted from deformed micro-pillars via the FIB lift-out technique: TEM analysis reveals the presence of nano-twins as major mechanism of plastic deformation, involving Shockley partial dislocations. The presence of twins was never reported in previous studies on the plasticity of bulk InSb: this deformation mechanism is discussed in the context of the plasticity of small-scale samples.

Plasticity Mechanism of Indium Antimony (InSb) in the Brittle Regime: Combined Study with Conventional TEM and LACBED

2007 ◽  
Vol 1026 ◽  
Author(s):  
Bouzid Kedjar ◽  
Ludovic Thilly ◽  
Jean-Luc Demenet ◽  
Jacques Rabier
Keyword(s):  
Transition Temperature ◽  
Deformation Mechanism ◽  
Partial Dislocation ◽  
Room Temperature ◽  
Confining Pressure ◽  
Temperature Deformation ◽  
Plasticity Mechanism ◽  
Brittle To Ductile Transition ◽  
Partial Dislocations ◽  
Thin Foils

AbstractIndium antimony (InSb) has been deformed in compression under gaseous confining pressure (Paterson apparatus) above and below the brittle to ductile transition occurring around 150°C. Thin foils have been prepared from the deformed samples and dislocations were characterized with conventional TEM as well as LACBED. This paper focuses on the room temperature deformation microstructures which appeared to be extremely complex with the observation of very well arranged network of perfect and partial dislocations. In such case, the traditional dislocation extinction conditions were extremely difficult to apply and only the use of the LACBED technique uncovered the nature of the observed dislocations and gave further insight to their interactions, revealing in particular the presence of partial dislocation dipoles. These original observations suggest a change of deformation mechanism at the brittle to ductile transition temperature.

High Temperature Deformation Mechanism Maps of NiAl

2004 ◽  
Vol 449-452 ◽  
pp. 57-60
Author(s):  
I.G. Lee ◽  
A.K. Ghosh
Keyword(s):  
High Temperature ◽  
Strain Rate ◽  
Deformation Mechanism ◽  
Calculation Method ◽  
Deformation Behavior ◽  
Tensile Tests ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Grain Sizes ◽  
Temperature Strain

In order to analyze high temperature deformation behavior of NiAl alloys, deformation maps were constructed for stoichiometric NiAl materials with grain sizes of 4 and 200 µm. Relevant constitute equations and calculation method will be described in this paper. These maps are particularly useful in identifying the location of testing domains, such as creep and tensile tests, in relation to the stress-temperature-strain rate domains experienced by NiAl.

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.

The mechanisms of plastic deformation of rapidly solidified Al3Ti and Al67Ni8Ti25 intermetallic compounds.

1988 ◽  
Vol 133 ◽  
Author(s):  
Vijay K. Vasudevan ◽  
Robert Wheeler ◽  
Hamish L. Fraser
Keyword(s):  
Room Temperature ◽  
Considerable Increase ◽  
Stacking Faults ◽  
Temperature Deformation ◽  
Deformation Microstructure ◽  
Partial Dislocations ◽  
Transmission Electron ◽  
The Mean ◽  
Rapidly Solidified ◽  
Mechanisms Of Plastic Deformation

ABSTRACTThe dislocation structures in rapidly solidified Al3Ti with the DO22 structure and the ternary Al-25Ti-8Ni (at.%) alloy with the L12 structure deformed in compression in the temperature range of 25 to 800°C have been studied by transmission electron microscopy. The room temperature deformation microstructure of the Al3Ti compound is characterized by the presence of stacking faults/order twins on {111} planes bounded by partial dislocations with Burgers vector b=1/6<112], as reported by others. At intermediate temperatures, besides the stacking faults, slip is also observed as bands on the {001] plane delineated by dislocations with b=1/2<110] which bound APB's. At 600°C, the reported increase in ductility is associated here with additional slip on the {001)<110], {001)[100] and {001)[010] systems. Dislocations with b=<110] exist as pairs of partial dislocations with b=1/2<110] connected by APB's. The mean separation between the partials was measured to be 30 nm, corresponding to an APB energy of ≍32 mJ.m-2 on the (001) plane. Observations also indicate that the APB energy is anisotropic, i.e., is considerably higher on the {111} planes compared to the {001) plane. The deformation microstructure of the Al-25Ti-8Ni L12 alloy is characterized by slip of dislocations with b=<110> gliding on {111} planes, a major fraction of which exist as dipoles. Following deformation at 300°C, there is essentially no evidence of dissociation of these dislocations, although some dissociated dislocations on (001) having b=l/2<110> are also observed. With an increase in temperature, there is a considerable increase in dislocation activity and strong evidence for 1/2<110> dissociated dislocations is present.

Twin Boundaries and Stacking Faults in Monazite (Monoclinic LaPO4)

2004 ◽  
Vol 819 ◽  
Author(s):  
Randall S. Hay
Keyword(s):  
Room Temperature ◽  
Deformation Twin ◽  
Stacking Faults ◽  
Temperature Deformation ◽  
Formation Mechanisms ◽  
Twin Boundaries ◽  
Partial Dislocations ◽  
Transmission Electron ◽  
Fault Migration ◽  
Lattice Formation

AbstractMonazite (LaPO4) was indented at room temperature. Deformation twin boundaries and stacking faults were characterized by high resolution transmission electron microscopy. Kinked deformation twins were also characterized and analyzed. Three types of stacking faults associated with climb-dissociated partial dislocations were observed. Two were found on twin boundaries, and a third in the lattice. Formation mechanisms are discussed. The superimposition of stacking faults along twin boundaries during deformation twinning and the glide of climb-dissociated partial dislocations allowed by stacking fault migration are discussed. The possible relationship between the formation mechanisms for these defects and the low- temperature recrystallization and self-annealing of defects in monazite is considered.

High Temperature Tensile Properties of Mg-5Li-3Al-1.5Zn-2RE Alloys

2012 ◽  
Vol 182-183 ◽  
pp. 189-193
Author(s):  
Ting Qu Li ◽  
M. Gao ◽  
S.H. Wang ◽  
Zhan Yi Cao
Keyword(s):  
High Temperature ◽  
Strain Rate ◽  
Tensile Properties ◽  
Deformation Mechanism ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Fracture Elongation ◽  
Dominant Deformation Mechanism ◽  
High Temperature Tensile ◽  
High Temperature Tensile Properties

In this paper, the high temperature tensile properties of the LAZ532-2RE alloy prepared by hot extruded processing after vacuum casting was investaged. The tensile properties of the extruded LAZ532-2RE alloy specimens were tested at different temperature with different strain rate. The microstructures near the fractured surfaces were observed using microscope in order to investigate the dominant deformation mechanism. The activation energy was calculated to explain the high temperature deformation mechanism. The result indicated that the strength of LAZ532-2RE alloy was high at the temperature range from 398K to 423K. Meanwhile, the fracture elongation of the alloy reaches 121% at 523K under strain rate 1×10-3s-1.

The Structure, Deformation and Properties of Al-5%Fe-Based Alloy

2011 ◽  
Vol 239-242 ◽  
pp. 1505-1509
Author(s):  
Da Jun Fu ◽  
Xiao Guang Yuan ◽  
Shuang Li
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Strain Rate ◽  
Room Temperature ◽  
Rolling Process ◽  
High Temperature Deformation ◽  
Temperature Deformation ◽  
Hot Deformation Behavior ◽  
Structure Deformation ◽  
Good Thermal Stability

To refine thick and brittle needle-like or sheet-like iron-rich phase in Al-Fe-based alloy, electromagnetic cast and solid extrusion were adopted for the preparation of billet of rolled alloy Al-5%Fe-1.2%Si-1%Mg-0.6%Cu-0.5%Mn. Studies were made of the effect of rolling process on the microstructure and mechanical properties especially on the mechanical properties at high temperature. The hot deformation behavior of Al-Fe alloy was simulated at the strain rate of 0.01s-1 to 10s-1 and the temperature between 783K and 693K. The results indicate that there is significant steady-state rheological feature on the alloy’s high temperature deformation and the flow stress is sensitive to strain rate and temperature. The tensile strength of the alloy can reach 348MPa at 150°C and 170 MPa at 300°C but with a drop of around 40% than that at room temperature, indicating that heat resistance of the alloy is better at 150-200°C, the strength simulated long at 80°C can reach 275MPa, with rather good thermal stability.

Twin Boundaries and Stacking Faults in Monazite (Monoclinic LaPO4)

2004 ◽  
Vol 821 ◽  
Author(s):  
Randall S. Hay
Keyword(s):  
Room Temperature ◽  
Deformation Twin ◽  
Stacking Faults ◽  
Temperature Deformation ◽  
Formation Mechanisms ◽  
Twin Boundaries ◽  
Partial Dislocations ◽  
Transmission Electron ◽  
Fault Migration ◽  
Lattice Formation

AbstractMonazite (LaPO4) was indented at room temperature. Deformation twin boundaries and stacking faults were characterized by high resolution transmission electron microscopy. Kinked deformation twins were also characterized and analyzed. Three types of stacking faults associated with climb-dissociated partial dislocations were observed. Two were found on twin boundaries, and a third in the lattice. Formation mechanisms are discussed. The superimposition of stacking faults along twin boundaries during deformation twinning and the glide of climb-dissociated partial dislocations allowed by stacking fault migration are discussed. The possible relationship between the formation mechanisms for these defects and the low- temperature recrystallization and self-annealing of defects in monazite is considered.

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