The kinetics of dislocation climb over hard particles—II. Effects of an attractive particle-dislocation interaction

Mechanical Behavior and Processing of Aluminum Metal Matrix Composites

“…As demonstratea elsewhere [227,228], _,ich an attractive particle-dislocation interaction in DS alloy leads to a well-defined threshold stress for creep which must be exceeded in order to detach the dislocation from particle after climbing. Most recently, it has been suggested [229] that dislocation detachment from the particle may be thermally activated and that in this case, creep may occur below the athermal "detachment stress".…”

“…In view of these similarities, it is interesting to examine whether dislocation processes proposed [209,[220][221][222][223][224][225][226][227][228][229] to account for the creep of DS alloys may also be applicable to the description of the creep of discontinuous SiCAl composites. Before attempting such an examination, it is appropriate to briefly review the characteristics of deformation processes for DS alloys.…”

“…In these models, the threshold stress is equal to: (a) the stress required to cause dislocation bowing between particles [209,220,221] (the Orowan stress), '% 0 , (b) the extra back stress, Tb, required to create the additional dislocation line length as the dislocation segment climbs over a particle (local climb) [222,2231, and (c) the stress required to detach the dislocation from the particle after climb is completed [227,228]. The magnitudes of the above threshold stresses along with the characterization of various parameters involved are given in Table 35.…”

“…In addition, the creep characteristics of the data of Park et al (high stress exponent and high activation energy) cannot be explained in terms of thermal activation of dislocation detachment from SiCp [228], since the athermal detachment stress, Td, is much lower than the smallest applied stress used in the investigation [89].…”

Mechanical Characterization of a Nano-ODS Steel Prepared by Low-Energy Mechanical Alloying

“…To understand the temperature-dependent mechanical properties of the ODS steel the contributions of different strengthening mechanisms have been considered: (i) solid solution (σSS); (ii) Bailey-Hirsch (σBH) due to dislocations; (iii) Hall-Petch (σHP); (iv) Orowan (σK) [29]; and (v) Arzt-Rősler-Wilkinson (σARW) for interfacial pinning [30,31].…”