The strain distribution in anisotropic polycrystalline aggregates subjected to an external stress field

1984 ◽  
Vol 49 (2) ◽  
pp. 243-262 ◽  
Author(s):  
C. M. Sayers
Keyword(s):  
Stress Field ◽  
Strain Distribution ◽  
External Stress ◽  
Polycrystalline Aggregates

The Influence of Stresses on the Surface-Near Defect Structure

1992 ◽  
Vol 262 ◽  
Author(s):  
M. Reiche ◽  
W. Nitzsche
Keyword(s):  
Stress Field ◽  
Defect Structure ◽  
Defect Formation ◽  
Nitride Layer ◽  
Nucleation And Growth ◽  
External Stress ◽  
Electrical Parameters ◽  
Initial Oxygen Concentration ◽  
Annealing Conditions ◽  
Initial Oxygen

ABSTRACTAn external stress field, induced at the film edge of a nitride layer, affects the defect generation in the surface-near region. Nucleation and growth of oxide precipitates and/or the generation of dislocations result in the reduction of the width of the denuded zone. The defect formation is discussed in dependence on the stress, gettering technique (annealing conditions), and on the initial oxygen concentration. The effect on electrical parameters is shown. The investigations prove that an additional oxide film (SiO2/Si3N4 films) does not relax completely the tensile stress induced by the nitride layer.

Slip Strains and Stresses in Polycrystalline Aggregates Under Cyclic Load

1966 ◽  
Vol 33 (2) ◽  
pp. 363-370 ◽  
Author(s):  
T. K. Tung ◽  
T. H. Lin
Keyword(s):  
Strain Distribution ◽  
Cyclic Load ◽  
Hysteresis Loops ◽  
Shear Stresses ◽  
Slip Systems ◽  
Combined Effects ◽  
Equivalent Problem ◽  
Simplifying Assumptions ◽  
Polycrystalline Aggregates ◽  
Active Slip

In an aggregate under moderate loads, plastic deformation is considered to occur in favorably oriented crystals on single active slip systems. The residual stresses, due to the slip strains, are expressed in terms of the slip strains by an equivalent problem in elasticity. The resolved shear stresses, owing to the combined effects of the slip strains and the external load, are in turn related to the slip strains by material property. The slip-strain distribution can thus be determined, and the stress distribution follows. Analytical solutions are obtained for a cyclic load of constant amplitude, under certain simplifying assumptions. They agree closely with rigorous, numerical incremental calculations for a specific case. For materials that strain-harden against reverse slip in each infinitesimal region, decreasing hysteresis loops occur with cyclic loading, and the present results corroborate the essential features of an earlier analysis by Orowan.

Laser surface nitriding of Ti6Al4V alloy coupled with an external stress field

2010 ◽  
Vol 25 (2) ◽  
pp. 344-349 ◽  
Author(s):  
Fu-Zhen Xuan ◽  
Li-Qin Cao ◽  
Zhengdong Wang ◽  
Shan-Tung Tu
Keyword(s):  
Residual Stress ◽  
Stress Field ◽  
Applied Stress ◽  
Nitrided Layer ◽  
Nitrogen Concentration ◽  
External Stress ◽  
Laser Surface ◽  
Ti6al4v Alloy ◽  
Surface Microhardness ◽  
Surprising Finding

We report on an approach for laser surface nitriding of Ti6Al4V alloy coupled with an applied stress field. A surprising finding was that, with increasing the applied stress levels, the decreased residual stress, the nitrogen concentration near the surface, and the surface microhardness of the nitrided layer were associated with the increased friction coefficient. Across the depth of the nitrided layer, the hardness, the elastic modulus, and the wear resistance (H/E) measured by nanoindentation decreased gradually and were ascribed to the gradient of nitrogen concentration in the melt zone.

The intrusive form of some basalt dykes showing flow lineation

1971 ◽  
Vol 108 (6) ◽  
pp. 489-499 ◽  
Author(s):  
John L. Roberts ◽  
David J. Sanderson
Keyword(s):  
Stress Field ◽  
External Stress ◽  
The North

SummaryThe dilational intrusion is described of some basalt dykes of Tertiary age into the Easdale Slates at Easdale, Argyllshire. The intrusive form of the dykes results from the walls of irregular fractures, guided by pre-existing planes of weakness, moving apart under magma pressure. The propagation of the fractures is discussed in relation to the external stress field controlling the intrusion of the dykes and the direction of opening of the fractures considered in relation to the magma pressure and the external stress field. The flow lineations developed at the margins of the dykes are discussed in terms of their mode of origin. Although the attitude of these lineations varies with the intrusive form of the dykes, the overall direction of flow of the magma was upwards to the north of northwest.

Impurity atoms clustering in a dislocation core in an external stress field

2000 ◽  
Vol 43 (6) ◽  
pp. 498-504
Author(s):  
M. V. Solodikhina ◽  
I. T. Suprun
Keyword(s):  
Stress Field ◽  
Dislocation Core ◽  
External Stress ◽  
Impurity Atoms

Effect of Size and Stress Field on Electronic Properties of ZnO Nanowires

2012 ◽  
Vol 724 ◽  
pp. 209-212
Author(s):  
Cheng He ◽  
Wen Xue Zhang
Keyword(s):  
Stress Field ◽  
First Principles ◽  
Output Voltage ◽  
Function Theory ◽  
Density Function Theory ◽  
External Stress ◽  
Zno Nanowires ◽  
Future Application ◽  
Band Maximum ◽  
Rapid Drop

The effects of external stress fieldfon band gapEg(D,f) of ZnO nanowires (NWs) in a diameter range ofD= 0.6 - 2.0 nm are investigated using first-principles density-function theory for the future application as nanogenerators. It is shown that theEg(D,0) values decreases with the increasing diameter of ZnO NWs without the stress field. Moreover,Eg(D, f) decreases with increasing offdue to the rapid drop of conduction band maximum of ZnO NWs whenDis constant. These findings imply thatEg(D,f) functions of ZnO NWs can be modulated by manipulatingDandf, which may be help for design of ZnO nanogenerators with a higher generation output voltage.

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