The finite-size analog of the Walgraef—Aifantis (WA) model of the "reaction + diffusion" type has been proposed to explain the size effects of dislocation patterning in fatigued metals. It has been demonstrated that the formation of certain patterns can be understood as a result of ...
The damage resulting from neutron irradiation has been examined in a number of metals using this technique. In some metals dislocation loops were observed while in others no structural changes were found subsequent to irradiation. The reasons for these differences in behaviour are not yet understood....
There has recently been a strong interest in modeling size-dependent plasticity in metals based on the concept of geometrically necessary dislocations. This article presents a brief summary of our viewpoints on geometrically necessary dislocations and their role in the development of continuum plasticity ...
For example, the plastic work hardening behavior of metal–matrix composites predicted by classical plasticity depends on the particle volume fraction and other nondimensional parameters (e.g., particle aspect ratio), but not particle size. For a typical dislocation density of 1016/m2 in work ...
While for metals such phenomena are commonly attributed to geometrically necessary dislocation densities, such an explanation cannot be applied to polymers. To provide a micromechanically motivated model for the indentation size effect in polymers, here we propose an elasto-plastic extension of the ...
YJ Wang,A Ishii,S Ogata 摘要: The grain size dependence of creep is critical to understand the plastic deformation mechanism of nanoscale metals. Here we used molecular dynamics to study the stress-induced grain size exponent transition in creep of nanocrystalline copper. The grain size exponent ...
The dislocation nature of plasticity enables crystalline metals to strain harden and renders them with a prominent strength size effect7, that is, the smaller the stronger. From the application perspective, understanding the small-scale plasticity in crystalline metals is of great impor- tance to ...
The data from nanoindentation for alpha brass when plotted, vs or (flow stress) vs , resulting from the ISE in a single specimen, concurs with that obtained from testing specimens with various levels of work hardening. This suggests that the ISE is driven by a dislocation mechanism. ...
Introduction A single particle microelectrode technique with a micromanipulator [1] was applied for the characterisation of the electrochemical and mass tr... M Zuleta,Pehr Bjrnbom,A Lundblad 被引量: 0发表: 0年 Production and Recovery of Electron-Induced Radiation Damage in a Number of Metals ...
The grain-size effect on short-range internal stresses (effective stress) is well explained in terms of a mean path length using classical dislocation modeling. The backstress dependence on grain size seems to be mainly the result of intergranular plastic-strain incompatibilities in relation with ...