Modeling of Orientation Dependence of Critical Resolved Shear Stress and Deformation Mechanisms on Yield Point of Austenitic Stainless Steels Hardened by Interstitial and Substitution Atoms

The proposed dislocation model describes the orientation dependence of the critical resolved shear stress (CRSS) and deformation mechanisms on the yield point in single crystals of austenitic stainless steel with nitrogen impurities. The model takes into account the following: the change of the interstitial atom position in the lattice from octahedral interstice to tetrahedral site owing to passage of a leading Shockley’s partial dislocation; the change in the separation width between two partial dislocation in external stress field; the relationship between the width of the extended dislocation and the elastic interaction of the extended dislocation with the impurity atoms.

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THE DEFORMATION OF NIOBIUM SINGLE CRYSTALS

Canadian Journal of Physics ◽

10.1139/p67-052 ◽

1967 ◽

Vol 45 (2) ◽

pp. 607-629 ◽

Cited By ~ 183

Author(s):

R. A. Foxall ◽

M. S. Duesbery ◽

P. B. Hirsch

Keyword(s):

Shear Stress ◽

Single Crystals ◽

High Vacuum ◽

Three Dimensional ◽

Orientation Dependence ◽

Ultra High Vacuum ◽

Text Type ◽

Dislocation Arrays ◽

Critical Resolved Shear Stress ◽

Twist Boundaries

Various orientations of single crystals of niobium, purified by ultra-high vacuum annealing, have been tested in compression at 295 °K and in tension at temperatures between 77 °K and 295 °K. The shear stress – shear strain curves show three-stage hardening in a manner similar to f.c.c. crystals. Analysis of the orientation dependence of the operative slip system suggests an asymmetry in the critical resolved shear stress for slip on {112} planes which increases with decreasing temperature. Explanations for this in terms of the various ways in which a [Formula: see text] type screw dislocation can dissociate have been proposed. It is found that dissociation on two {112} planes or composite dissociation on {110} and {112} planes leads to a satisfactory qualitative explanation of the experimental results.The dislocation distribution occurring as a function of strain has been studied for crystals of a single glide orientation deformed in tension at 295 °K. [Formula: see text] sections from crystals deformed into stage I contain clusters of primary edge dipoles. The density of secondary dislocations is low (~10%). Sections from crystals deformed into stage II were chosen such that the three-dimensional nature of the dislocation arrays could be investigated. The distribution shows strong similarities to those observed in copper crystals (Steeds 1966), i.e. edge multipole walls, tilt and twist boundaries. The density of secondary dislocations is high, being of the same order as the primary density.

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Plastic Deformation of Ni3Nb Single Crystals

MRS Proceedings ◽

10.1557/proc-552-kk10.7.1 ◽

1998 ◽

Vol 552 ◽

Cited By ~ 2

Author(s):

Kouji Hagihara ◽

Takayoshi Nakano ◽

Yukichi Umakoshi

Keyword(s):

Plastic Deformation ◽

Shear Stress ◽

Single Crystals ◽

Crystal Orientation ◽

Strengthening Mechanism ◽

Orientation Dependence ◽

Slip Model ◽

Compression Tests ◽

Increasing Temperature ◽

Critical Resolved Shear Stress

ABSTRACTTemperature dependence of yield stress and operative slip system in Ni3Nb single crystals with the DOa structure was investigated in comparison with that in an analogous L12 structure. Compression tests were performed at temperatures between 20 °C and 1200 °C for specimens with loading axes perpendicular to (110), (331) and (270).(010)[100] slip was operative for three orientations, while (010)[001] slip for (331) and {211} <10 7 13> twin for (270) orientations were observed, depending on deformation temperature. The critical resolved shear stress (CRSS) for the (010)[100] slip anomaly increased with increasing temperature showing a maximum peak between 400 °C and 800 °C depending on crystal orientation. The CRSS showed orientation dependence and no significant strain rate dependence in the temperature range for anomalous strengthening. The [100] dislocations with a screw character were aligned on the straight when the anomalous strengthening occurred. The anomalous strengthening mechanism for (010)[100] slip in Ni3Nb single crystals is discussed on the basis of a cross slip model which has been widely accepted for some L12-type compounds.

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CRITICAL RESOLVED SHEAR STRESS OF LEAD

Canadian Journal of Physics ◽

10.1139/p67-087 ◽

1967 ◽

Vol 45 (2) ◽

pp. 1189-1207 ◽

Cited By ~ 10

Author(s):

F. Weinberg

Keyword(s):

Shear Stress ◽

Flow Stress ◽

Melting Point ◽

Temperature Dependence ◽

Orientation Dependence ◽

Impurity Level ◽

Optimum Conditions ◽

Average Value ◽

Critical Resolved Shear Stress

Measurements of the critical resolved shear stress of lead are reported as a function of temperature, purity, solute additions, and orientation. By annealing in situ it was found that the value of the CRSS can be reduced, the scatter between specimens decreased, and the same specimen can be tested a number of times.Over the temperature range 4.2 °K to 600 °K (the melting point) the CRSS decreased from 53 g/mm2 to approximately 10 g/mm2. Between 100 °K and 300 °K the temperature dependence of the CRSS is the same as that of the shear modulus.It was found that the CRSS is relatively insensitive to differences in the trace impurity level and to solute additions of 0.1% Sn and 0.02% Cu. Additions of 1.0% Sn appreciably increase the CRSS at low temperatures.The orientation dependence of the CRSS is similar to that shown for copper, with higher values at the edges and corners of the stereographic triangle.Under optimum conditions the average value of the CRSS of lead is 34 g/mm2 at 78 °K. This value is anomalously high when compared to that of copper, using σ α [Formula: see text] for the flow stress to make the comparison.

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Stacking Faults and Dislocation Dissociation in MoSi2

MRS Proceedings ◽

10.1557/proc-1128-u07-10 ◽

2008 ◽

Vol 1128 ◽

Cited By ~ 3

Author(s):

Miroslav Cak ◽

Mojmir Sob ◽

Vaclav Paidar ◽

Vaclav Vitek

Keyword(s):

Shear Stress ◽

Slip System ◽

Density Functional ◽

Deformation Behaviour ◽

Stacking Faults ◽

Dislocation Core ◽

Orientation Dependence ◽

The Body ◽

Anisotropic Elastic ◽

Critical Resolved Shear Stress

AbstractThe intermetallic compound MoSi2 crystallises in the body-centred-tetragonal C11b structure and while it is brittle when loaded in tension, it deforms plastically in compression even at and below the room temperature. The ductility of MoSi2 is controlled by the mobility of 1/2〈331] dislocations on {013) planes but the critical resolved shear stress for this slip system depends strongly on the orientation of loading and it is the highest for compression along the 〈001] axis. Such deformation behaviour suggests that the dislocation core is controlling the slip on the {013)〈331] system. Since the most important core effect is dissociation into partial dislocations connected by metastable stacking faults the first goal of this paper is to ascertain such faults. This is done by employing the concept of the γ-surface. The γ-surfaces have been calculated for the (013) and (110) planes using a method based on the density functional theory. While there is only one possible stacking fault on the (110) plane, three distinct stacking faults have been found on the (013) plane. This leads to a variety of possible dislocation splittings and the energetics of these dissociations has been studied by employing the anisotropic elastic theory of dislocations. The most important finding is the non-planar dissociation of the 1/2〈331] screw dislocation that is favoured over the planar splittings and may be responsible for the orientation dependence of the critical resolved shear stress for the {013)〈331] slip system.

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Effect of solute content and temperature on the deformation mechanisms and critical resolved shear stress in Mg-Al and Mg-Zn alloys

Acta Materialia ◽

10.1016/j.actamat.2019.03.027 ◽

2019 ◽

Vol 170 ◽

pp. 155-165 ◽

Cited By ~ 15

Author(s):

J.-Y. Wang ◽

N. Li ◽

R. Alizadeh ◽

M.A. Monclús ◽

Y.W. Cui ◽

...

Keyword(s):

Shear Stress ◽

Deformation Mechanisms ◽

Solute Content ◽

Critical Resolved Shear Stress ◽

Zn Alloys

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The yield stress of single crystals of α-phase Cu-Ni-Pd and Cu-Pd alloys

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1989.0054 ◽

1989 ◽

Vol 423 (1865) ◽

pp. 267-278 ◽

Cited By ~ 3

Keyword(s):

Shear Stress ◽

Single Crystals ◽

Yield Stress ◽

Yield Point ◽

Concentration Dependence ◽

Atomic Concentration ◽

Α Phase ◽

Alloy Series ◽

Pd Alloy ◽

Critical Resolved Shear Stress

Single crystals of Cu- x at. % Ni- x at. % Pd [ x ═ 1 to 6] and Cu- x at. % Pd alloys [ x ═ 1, 2, 4 and 6] were deformed in tension at 293 K and 4.2 K. The crystals had the [331] {͞110} {͞1͞16} orientation which has two equivalent {͞1͞11} <011> and {͞1͞11} <101> primary glide systems. The concentration dependence of the critical resolved shear stress σ at the yield point for both alloy series was given by σ T ═ σ 0 ( T )+ A ( T ) c α , where σ 0 ( T ) and A ( T ) are constants for one alloy series at T K and c is the atomic concentration of the solute. The exponent α is 0.72 or 0.73 for the Cu-Ni-Pd and 0.61 or 0.62 for the Cu-Pd alloy series at 293 or 4.2 K. The data for both alloy series could be fitted to the relation σ 4.2K -σ 293K ═ 1.046+0.526σ 4.2K [MPa]. This establishes the stress equivalence behaviour of single crystals of these alloys.

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Orientation and temperature dependence of plastic deformation processes in 3·25% silicon iron

Proceedings of the Royal Society of London Series A - Mathematical and Physical Sciences ◽

10.1098/rspa.1963.0111 ◽

1963 ◽

Vol 274 (1356) ◽

pp. 5-20 ◽

Cited By ~ 28

Keyword(s):

Shear Stress ◽

Close Agreement ◽

Orientation Dependence ◽

Twin Plane ◽

Slip Direction ◽

Silicon Iron ◽

Slip Bands ◽

Deformation Processes ◽

Twinning Direction ◽

Critical Resolved Shear Stress

Single crystals of a 3·25 % silicon iron were deformed in tension between 20 and 293 °K. The orientation was varied systematically between [010] and [110], to determine the orientation dependence of slip and twinning. The operative slip and twinning systems were measured by two surface analysis. At 20 °K all specimens twinned and fractured; at 77 °K crystals within 11° of [010] twinned and fractured and the remainder yielded before fracture; at 195 and 293 °K all specimens yielded. Yielding occurred by the formation and propagation of slip bands along the specimen. At 77 °K slip was confined to {011} planes but at higher temperatures slip occurred on the plane containing the <111> slip direction with the maximum resolved shear stress independent of whether or not it was a low index plane. The yield propagation stress varied with orientation in close agreement with that expected for slip on an {011} <111> system at all temperatures. Twinning occurred on those systems with the maximum resolved shear stress on the twin plane in the twinning direction and the results support a critical resolved shear stress law.

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ORIENTATION DEPENDENCE OF YIELD IN BODY-CENTERED CUBIC METALS

Canadian Journal of Physics ◽

10.1139/p67-080 ◽

1967 ◽

Vol 45 (2) ◽

pp. 1091-1099 ◽

Cited By ~ 40

Author(s):

D. Hull ◽

J. F. Byron ◽

F. W. Noble

Keyword(s):

Shear Stress ◽

Deformation Behavior ◽

Orientation Dependence ◽

Compressive Deformation ◽

Slip Systems ◽

Body Centered Cubic ◽

Cubic Metals ◽

The Asymmetry ◽

Critical Resolved Shear Stress ◽

And Tungsten

Recent observations relating to the critical resolved shear stress for slip in tantalum and tungsten are reported. The results of tensile and compressive deformation are discussed in terms of the operative slip systems and the possible asymmetry of {112} [Formula: see text] slip. It is concluded that the asymmetry hypothesis is unable to account satisfactorily for anomalies in the deformation behavior of these materials.

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