✍ Scribed by Y. Estrin; H.S. Kim; F.R.N. Nabarro
No coin nor oath required. For personal study only.
Dislocation generation by a Frank-Read source was considered for the case of nanocrystalline metallic materials. It was shown that thermally activated operation of this mechanism, which was proposed in the literature as an explanation for the observed grain size dependence of the strain rate sensitivity (SRS) of the flow stress, is only possible in a very limited range of the source lengths and stresses. By comparing the calculated SRS with the experimental data for copper, it was further demonstrated that the thermally activated Frank-Read mechanism can be discarded as a process underlying the observed strain rate sensitivity data.
📜 SIMILAR VOLUMES
## Abstract On the basis of a result obtained by DE WIT and KOEHLER an exact formula has been derived for the critical shear stress of a Frank‐Read source, which can be applied to anisotropic crystals as well. Application of this formula in a few numerical cases shows that the effect of the anisotr