The slip modes of titanium and the effect of purity on their occurrence during tensile deformation of single crystals

1954 ◽  
Vol 226 (1165) ◽  
pp. 216-226 ◽  
Keyword(s):  
Shear Stress ◽  
Slip System ◽  
Single Crystals ◽  
Tensile Deformation ◽  
Interstitial Impurity ◽  
Slip Systems ◽  
Slip Planes ◽  
Critical Resolved Shear Stress ◽  
Interstitial Elements

Single-crystal test specimens of van Arkel titanium were obtained by a modification of the strain anneal technique.The modes of slip have been identified as (101̄0) [112̄0],(101̄1) [112̄0], and (0001) [112̄0]. It has been shown that not only does the interstitial impurity affect the magnitude of the critical resolved shear stress but also the relative values for the three slip systems. (101̄0) is the principal slip system and is favoured by increasing purity. A possible mechanism for the role of oxygen and nitrogen in this effect is put forward wherein it is shown that the interstitial sites occupied are such that interstitial elements render slip more difficult on two of the three slip planes in titanium.

Effect of Temperature and Crystal Orientation on the Plasticity (SLIP) Evolution in Single Crystal Nickel Base Superalloy Notched Specimens

2007 ◽  
Author(s):  
Shadab Siddiqui ◽  
Nagaraj K. Arakere ◽  
Fereshteh Ebrahimi
Keyword(s):  
Shear Stress ◽  
Single Crystal ◽  
Element Model ◽  
Effect Of Temperature ◽  
Nickel Base Superalloy ◽  
Shear Stresses ◽  
Slip Systems ◽  
Slip Planes ◽  
Nickel Base ◽  
Critical Resolved Shear Stress

A comprehensive numerical investigation of plasticity (slip) evolution near notches was conducted at 28°C and 927°C, for two crystallographic orientations of double-notched single crystal nickel base superalloys (SCNBS) specimens. The two specimens have a common loading orientation of <001> and have notches parallel to the <010> (specimen I) and <110> (specimen II) orientation, respectively. A three dimensional anisotropic linear elastic finite element model was employed to calculate the stress field near the notch of these samples. Resolved shear stress values were obtained near the notch for the primary octahedral slip systems ({111} <110>) and cube slip systems ({100} <110>). The effect of temperature was incorporated in the model as changes in the elastic modulus values and the critical resolved shear stress (CRSS). The results suggest that the number of dominant slip systems (slip systems with the highest resolved shear stress) and the size and the shape of the plastic zones around the notch are both functions of the orientation as well as the test temperature. A comparison between the absolute values of resolved shear stresses near the notch at 28°C and 927°C on the {111} slip planes revealed that the plastic zone size and the number of activated dominant slip systems are not significantly affected by the temperature dependency of the elastic properties of the SCNBS, but rather by the change in critical resolved shear stress of this material with temperature. The load required to initiate slip was found to be lower in specimen II than in specimen I at both temperatures. Furthermore, at 927°C the maximum resolved shear stress (RSS) on the notch surface was found to be greater on the {100} slip planes as compared with the {111} slip planes in both specimens. The results from this study will be helpful in understanding the slip evolution in SCNBS at high temperatures.

Room Temperature Deformation in “Soft” Orientation Nial Single Crystals

1990 ◽  
Vol 213 ◽  
Author(s):  
R.D. Field ◽  
D.F. Lahrman ◽  
R. Darolia
Keyword(s):  
Shear Stress ◽  
Elevated Temperature ◽  
Single Crystals ◽  
Room Temperature ◽  
Dislocation Motion ◽  
Temperature Deformation ◽  
Slip Planes ◽  
Schmid Factor ◽  
Critical Resolved Shear Stress ◽  
Active Slip

ABSTRACTA detailed study of deformation of NiAl single crystals in two soft orientations, <110> and <111>, has been conducted. The Schmid factor favors {100} slip in the former and {110} slip in the latter. Detailed dislocation analysis, critical resolved shear stress measurements, and slip trace analysis have been performed to determine the nature of dislocation motion and interactions in this material. Particular attention is given to prismatic loops formed during deformation, since the shapes of these loops reveal the active slip planes. Similar loop morphologies observed in elevated temperature [001] oriented tensile specimens are also discussed.

Tensile Deformation Behavior of Magnesium Single Crystals with Different Yttrium Concentrations

2021 ◽  
Vol 1016 ◽  
pp. 516-521
Author(s):  
Tomohiro Hanada ◽  
Masayuki Tsushida ◽  
Hiromoto Kitahara ◽  
Shinji Ando
Keyword(s):  
Slip System ◽  
Single Crystals ◽  
Yield Stress ◽  
Tensile Deformation ◽  
Tensile Tests ◽  
Second Order ◽  
Pyramidal Slip ◽  
Tensile Deformation Behavior ◽  
Yttrium Addition ◽  
Critical Resolved Shear Stress

Tensile tests of Mg-Y single crystals with different yttrium concentrations: 0.07 and 0.3 at.% were carried out to investigate effects of yttrium on pyramidal <c+a> slip system. In Mg-0.07at%Y alloy single crystals, {11 2}< 23> second order pyramidal <c+a> slip was activated and yield stress increased, compared to pure Mg single crystals. On other hand, in Mg-0.3at%Y alloy single crystals, {10 1}< 23> first order pyramidal <c+a> slip was activated and yield stress increased, compared to Mg-0.07at%Y alloy single crystals. The change in slip system by yttrium addition would be caused by increasing critical resolved shear stress (CRSS) for second order pyramidal slip.

Characteristics of Ordinary ½⟨110] Slip in Single Crystals of γ-TiAl

1998 ◽  
Vol 552 ◽  
Author(s):  
S. Jiao ◽  
N. Bird ◽  
P. B. Hirsch ◽  
G. Taylor
Keyword(s):  
Shear Stress ◽  
Single Crystals ◽  
Yield Stress ◽  
Dislocation Slip ◽  
Slip Systems ◽  
Different Temperatures ◽  
Critical Resolved Shear Stress ◽  
Thermal Reversibility ◽  
Edge Dislocations

ABSTRACTA study of the occurrence of ordinary slip in single crystals of Ti 54.5 at% Al with various orientations at different temperatures shows that the critical resolved shear stress is approximately the same for ¼⟨110] slip on {111} and {110} planes near the peak of the yield stress anomaly. However the shapes of the glide loops are quite different, suggesting that the order of relative mobilities of screw and edge dislocations is reversed in the two cases. The reason for this and its possible effect on the mechanism responsible for the yield stress anomaly of ½⟨110] {111} slip are discussed. Experiments on the thermal reversibility of the yield stress when either ordinary- or super- dislocation slip systems are operating at both temperatures have shown that the yield stress is reversible for the latter but not reversible in the former case.

Slip systems and critical resolved shear stress in pyrite: an electron backscatter diffraction (EBSD) investigation

2008 ◽  
Vol 72 (6) ◽  
pp. 1181-1199 ◽  
Author(s):  
C. D. Barrie ◽  
A. P. Boyle ◽  
S. F. Cox ◽  
D. J. Prior
Keyword(s):  
Shear Stress ◽  
Slip System ◽  
Single Crystal ◽  
Electron Backscatter Diffraction ◽  
Lattice Rotation ◽  
Slip Systems ◽  
Boundary Trace ◽  
Electron Backscatter ◽  
Backscatter Diffraction ◽  
Critical Resolved Shear Stress

AbstractA suite of experimentally deformed single-crystal pyrite samples has been investigated using electron backscatter diffraction (EBSD). Single crystals were loaded parallel to <100> or <110> and deformed at a strain rate of 10-5s-1, confining pressure of 300 MPa and temperatures of 600°C and 700°C. Although geometrically (Schmid factor) the {001}<100> slip system should not be activated in <100> loaded samples, lattice rotation and boundary trace analyses of the distorted crystals indicate this slip system is easier to justify. Determination of 75 MPa as the critical resolved shear stress (CRSS) for {001}<100> activation, in the <110> loaded crystals, suggests a crystal misalignment of ~5—15° in the <100> loaded crystals would be sufficient to activate the {001}<100> slip system. Therefore, {001}<100> is considered the dominant slip system in all of the single-crystal pyrite samples studied. Slip-system analysis of the experimentally deformed polycrystalline pyrite aggregates is consistent with the single-crystal findings, with the exception that {001}<11̄> also appears to be important, although less common than the {001}<100> slip system. The lack of crystal preferred orientation (CPO) development in the polycrystalline pyrite aggregates can be accounted for by the presence of two independent symmetrically equivalent slip systems more than satisfying the von Mises criterion.

scholarly journals Ca-induced Plasticity in Magnesium Alloy: EBSD Measurements and VPSC Calculations

Crystals ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 67 ◽  
Author(s):  
Umer Masood Chaudry ◽  
Kotiba Hamad ◽  
Jung-Gu Kim
Keyword(s):  
Shear Stress ◽  
Magnesium Alloy ◽  
Slip System ◽  
Basal Slip ◽  
Room Temperature ◽  
Prismatic Slip ◽  
Slip Systems ◽  
Electron Backscattered Diffraction ◽  
Self Consistent ◽  
Critical Resolved Shear Stress

In the present work, Ca-induced plasticity of AZ31 magnesium alloy was studied using electron backscattered diffraction (EBSD) measurements supported by viscoplastic self-consistent (VPSC) calculations. For this purpose, alloy samples were stretched to various strains (5%, 10%, and 15%) at room temperature and a strain rate of 10−3 s−1. The EBSD measurements showed a higher activity of non-basal slip system (prismatic slip) as compared to that of tension twins. The VPSC confirmed the EBSD results, where it was found that the critical resolved shear stress of the various slip systems and their corresponding activities changed during the stretching of the alloy samples.

scholarly journals The Stress Induced Martensite-Austenite Interface in Fe-15Ni-15Cr Single Crystals

1973 ◽  
Vol 31 ◽  
pp. 110-111
Author(s):  
G. A. Stone ◽  
G. Thomas
Keyword(s):  
Shear Stress ◽  
Slip System ◽  
Single Crystal ◽  
Single Crystals ◽  
Habit Plane ◽  
Maximum Shear Stress ◽  
Crystal Axis ◽  
Surface Study

A single crystal stressed in the [3]𝛄 direction at 185°K was transformed to 5% 𝛂 martensite and 2% Ɛ martensite by volume. The austenite slip system of maximum shear stress is the (11)𝛄 [01)𝛄. Fig. 1 shows a two surface study using the electron and optical microscopes. The a martensite is confined between £martensite plates with the (0001)Ɛ ∥ (11)𝛄. The size of the acicular martensite crystals is controlled by the spacing of the £ martensite plates. These £ martensite plates are seen in Fig. 1A as dark vertical bands. The axes of the acicular crystals lie in the (11)𝛄 plane. The £ martensite habit plane is defined as the plane perpendicular to the (11)𝛄 containing the vector defining the crystal axis.

Plastic Deformation of Mo(Si,Al)2 Single Crystals with the C40 Structure

1996 ◽  
Vol 460 ◽  
Author(s):  
M. Moriwaki ◽  
K. Ito ◽  
H. Inui ◽  
M. Yamaguchi
Keyword(s):  
Single Crystals ◽  
Deformation Behavior ◽  
Basal Slip ◽  
Room Temperature ◽  
Slip Systems ◽  
Temperature Range ◽  
Al Content ◽  
Partial Dislocations ◽  
Increasing Temperature ◽  
Critical Resolved Shear Stress

ABSTRACTThe deformation behavior of single crystals of Mo(Si,Al)2 with the C40 structure has been studied as a function of crystal orientation and Al content in the temperature range from room temperature to 1500°C in compression. Plastic flow is possible only above 1100°C for orientations where slip along <1120> on (0001) is operative and no other slip systems are observed over whole temperature range investigated. The critical resolved shear stress for basal slip decreases rapidly with increasing temperature and the Schmid law is valid. Basal slip appears to occur through a synchroshear mechanism, in which a-dislocations (b=1/3<1120>) dissociate into two synchro-partial dislocations with the identical Burgers vector(b*1/6<1120>) and each synchro-partial further dissociates into two partials on two adjacent planes.

Sign in / Sign up

Export Citation Format

Share Document