Topic
Grain boundary strengthening
About: Grain boundary strengthening is a research topic. Over the lifetime, 8585 publications have been published within this topic receiving 286232 citations.
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TL;DR: In this paper, the drag on a grain boundary produced by an impurity atmosphere is examined in detail, and is found to depend on the velocity of the grain boundary relative to the diffusivity of the impurity and its interaction with the grain boundaries.
1,227 citations
01 Apr 1971
TL;DR: In this paper, the problem of sliding at a nonplanar grain boundary is considered in detail, and the results give solutions to the following problems: 1) How much sliding occurs in a polycrystal when neither diffusive flow nor dislocation motion is possible? 2) What is the sliding rate at a wavy or stepped grain boundary when diffusional flow of matter occurs? 3) How is the rate of diffusional creep in polycrystals in which grain boundaries slide? 4) how is this creep rate affected by grain shape, and grain boundary migration? 5)
Abstract: The problem of sliding at a nonplanar grain boundary is considered in detail. The stress field, and sliding displacement and velocity can be calculated at a boundary with a shape which is periodic in the sliding direction (a wavy or stepped grain boundary): a) when deformation within the crystals which meet at the boundary is purely elastic, b) when diffusional flow of matter from point to point on the boundary is permitted. The results give solutions to the following problems. 1) How much sliding occurs in a polycrystal when neither diffusive flow nor dislocation motion is possible? 2) What is the sliding rate at a wavy or stepped grain boundary when diffusional flow of matter occurs? 3) What is the rate of diffusional creep in a polycrystal in which grain boundaries slide? 4) How is this creep rate affected by grain shape, and grain boundary migration? 5) How does an array of discrete particles influence the sliding rate at a grain boundary and the diffusional creep rate of a polycrystal? The results are compared with published solutions to some of these problems.
1,101 citations
TL;DR: In this article, the effects of size on predominantly mechanical properties of materials are reviewed at a first-order level, and important aspects can be understood from the point of view of the interaction of a characteristic length (which may be as diverse as the dislocation radius of curvature at a given stress or the magnetic exchange length) with a size parameter (grain or particle size, or film thickness).
1,068 citations
TL;DR: In this paper, a study experimentale de la variation de la durete en fonction de la grosseur de grain for des materiaux nanocristallins is presented.
1,025 citations
TL;DR: In this paper, the pore and grain boundary structures in sintered powder compacts are presented to provide the basis for qualitative description of the important phases of the course of densification.
Abstract: Photomicrographs of pore and grain boundary structures in sintered powder compacts are presented to provide the basis for qualitative description of the important phases of the course of densification. From this guide, appropriate grain shapes and pore shapes and locations are selected for the formulation of diffusion sintering models. The principle models presented are for bulk diffusion transport with the grain boundaries as vacancy sinks when the pore phase is continuous and coincident with three grain edges, and also when the pore phase is discontinuous and located at four-grain corners. These models predict that the rate of density change is constant when the diffusion coefficient and grain size are constant. The need for simultaneous isothermal densification and grain growth data is indicated. The explicit change in densification rate with discontinuous grain growth is predicted in terms of pore spacing and grain size.
961 citations