Plastic Deformation of 〈001〉 Single-Crystal SrTiO3 by Compression at Room Temperature

2011 ◽  
Vol 94 (9) ◽  
pp. 3104-3111 ◽  
Author(s):  
Kai-Hsun Yang ◽  
New-Jin Ho ◽  
Hong-Yang Lu
Keyword(s):  
Plastic Deformation ◽  
Single Crystal ◽  
Room Temperature

Plastic deformation mechanisms in a new Ni-base single crystal superalloy at room temperature

2017 ◽  
Vol 268 (2) ◽  
pp. 186-192 ◽  
Author(s):  
P. ZHANG ◽  
Y. YUAN ◽  
Z. GAO ◽  
B. LI ◽  
G. YANG ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Single Crystal ◽  
Room Temperature ◽  
Single Crystal Superalloy ◽  
Deformation Mechanisms

Preliminary Investigations of a High Temperature Cu-13.3%Al-4%Ni Shape Memory Alloy Single Crystal

2003 ◽  
Author(s):  
Steve Trigwell ◽  
Ganesh Kumara K. ◽  
Abhijit Bhattacharyya ◽  
Muhammed A. Qidwai
Keyword(s):  
Plastic Deformation ◽  
Shape Memory Alloy ◽  
Single Crystal ◽  
Shape Memory ◽  
Room Temperature ◽  
Alloy Single Crystal ◽  
Stress Strain ◽  
Stress Cycling ◽  
Constitutive Response ◽  
Martensite Reorientation

Preliminary investigations on the constitutive response of a Cu-13.3%Al-4%Ni (wt%) shape memory alloy single crystal with stress-free transformation temperatures around 100 to 150°C are reported. Room temperature stress cycling tests were carried out at very low deformation rates. Reproducible stress/strain curves of up to 9% strain due to detwinning (martensitematensite phase transformations) with no plastic deformation were obtained. The data also indicated that a period of stress cycling is required to stabilize the material before reproducible stress-strain curves are obtained due to martensite reorientation.

Tribological Properties of KDP Single Crystal

2014 ◽  
Vol 490-491 ◽  
pp. 134-137
Author(s):  
Chun Peng Lu ◽  
Hang Gao ◽  
Xiao Ji Teng
Keyword(s):  
Plastic Deformation ◽  
Single Crystal ◽  
Tribological Properties ◽  
Room Temperature ◽  
Surface Damage ◽  
Kdp Crystal ◽  
Scratch Tests ◽  
Elastic And Plastic Deformation ◽  
Kdp Crystals

Scratch tests on (001) face, doubler face and tripler face of KDP crystals are carried out at room temperature. It shows that the friction ceoffcients of different crystal faces are affected seriously by the crystal oritations, their variation periods of (001) face, doubler face and tripler face are 90o, 180o and 180o, their attitudes of relative anisotropy are 50%, 43.8% and 43.8%, and all of them are less than 0.4. The scratch mechanism of KDP crystal consists of four types: elastic and plastic deformation, ploughing, microchip, and surface damage. Differences between elastic and plastic deformation and ploughing are not obvious due to the soft-brittle nature of KDP crystal.

scholarly journals Revealing the Plastic Mode of Time-Dependent Deformation of a LiTaO3 Single Crystal by Nanoindentation

Micromachines ◽  
2020 ◽  
Vol 11 (9) ◽  
pp. 878
Author(s):  
Shengyun Zhou ◽  
Xianwei Huang ◽  
Congda Lu ◽  
Yunfeng Liu ◽  
Taihua Zhang ◽  
...  
Keyword(s):  
Plastic Deformation ◽  
Single Crystal ◽  
Room Temperature ◽  
Time Dependent ◽  
High Shear ◽  
Compression Stress ◽  
Creep Flow ◽  
Secondary Cracks ◽  
Loading Sequence ◽  
Surface Morphologies

Recently, instrumental nanoindentation has been widely applied to detect time-dependent plastic deformation or creep behavior in numerous materials, particularly thin films and heterogeneous materials. However, deformation mechanism at nanoindentation holding stage has not been well revealed hitherto. In the current work, nanoindentation holding tests with high loads were performed on a brittle LiTaO3 single crystal. The surface morphologies of residual impressions with various holding times were investigated. It was indicated that generation of secondary cracks and propagation of both main and secondary cracks were the dominating mechanism for time-dependent plastic deformation at the initial holding stage, and the density and length of cracks were invariable at the steady-state holding stage, which suggested a nonlocalized plastic deformation beneath the indenter. It could be concluded that time-dependent plastic deformation of brittle ceramic under nanoindentation is composed of instant cracking as the continuation of loading sequence and homogeneous creep flow by high shear-compression stress at room temperature.

Mechanical Properties and Dislocation Structure of Single Crystal Cdte Deformed in Compression at 300°C

1976 ◽  
Vol 34 ◽  
pp. 592-593
Author(s):  
Ernest L. Hall ◽  
J. B. Vander Sande
Keyword(s):  
Mechanical Properties ◽  
Single Crystal ◽  
Dislocation Structure ◽  
Room Temperature ◽  
Elevated Temperatures ◽  
Strain Curve ◽  
Optical Devices ◽  
Semiconductor Compound ◽  
Wide Range ◽  
Sample Orientation

The present paper describes research on the mechanical properties and related dislocation structure of CdTe, a II-VI semiconductor compound with a wide range of uses in electrical and optical devices. At room temperature CdTe exhibits little plasticity and at the same time relatively low strength and hardness. The mechanical behavior of CdTe was examined at elevated temperatures with the goal of understanding plastic flow in this material and eventually improving the room temperature properties. Several samples of single crystal CdTe of identical size and crystallographic orientation were deformed in compression at 300°C to various levels of total strain. A resolved shear stress vs. compressive glide strain curve (Figure la) was derived from the results of the tests and the knowledge of the sample orientation.

Electron microscope studies of the plastic deformation of ternary alloys based on GaAs

1990 ◽  
Vol 48 (4) ◽  
pp. 1120-1120
Author(s):  
R. Haswell ◽  
U. Bangert ◽  
P. Charsley
Keyword(s):  
Plastic Deformation ◽  
Electron Microscope ◽  
Room Temperature ◽  
Stacking Faults ◽  
The Other ◽  
Ternary Alloys ◽  
Dislocation Mobility ◽  
Semiconducting Materials ◽  
Micro Indentation

A knowledge of the behaviour of dislocations in semiconducting materials is essential to the understanding of devices which use them . This work is concerned with dislocations in alloys related to the semiconductor GaAs . Previous work on GaAs has shown that microtwinning occurs on one of the <110> rosette arms after indentation in preference to the other . We have shown that the effect of replacing some of the Ga atoms by Al results in microtwinning in both of the rosette arms.In the work to be reported dislocations in specimens of different compositions of Gax Al(1-x) As and Gax In(1-x) As have been studied by using micro indentation on a (001) face at room temperature . A range of electron microscope techniques have been used to investigate the type of dislocations and stacking faults/microtwins in the rosette arms , which are parallel to the [110] and [10] , as a function of composition for both alloys . Under certain conditions microtwinning occurs in both directions . This will be discussed in terms of the dislocation mobility.

Single Crystal Growth of High-Pressure Phases of Ice and Salt Hydrate Far Below the Original Melting Point by Mixing Alcohol: Crystal Structure Determination of Magnesium Chloride Heptahydrate

2020 ◽  
Author(s):  
Keishiro Yamashita ◽  
Kazuki Komatsu ◽  
Hiroyuki Kagi
Keyword(s):  
Crystal Structure ◽  
High Pressure ◽  
Crystal Growth ◽  
Single Crystal ◽  
Room Temperature ◽  
Growth Technique ◽  
Salt Hydrate ◽  
X Ray

An crystal-growth technique for single crystal x-ray structure analysis of high-pressure forms of hydrogen-bonded crystals is proposed. We used alcohol mixture (methanol: ethanol = 4:1 in volumetric ratio), which is a widely used pressure transmitting medium, inhibiting the nucleation and growth of unwanted crystals. In this paper, two kinds of single crystals which have not been obtained using a conventional experimental technique were obtained using this technique: ice VI at 1.99 GPa and MgCl<sub>2</sub>·7H<sub>2</sub>O at 2.50 GPa at room temperature. Here we first report the crystal structure of MgCl2·7H2O. This technique simultaneously meets the requirement of hydrostaticity for high-pressure experiments and has feasibility for further in-situ measurements.

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