Effect of deformation geometry on the intermittent plastic flow associated with the Portevin–Le Chatelier effect
✍ Scribed by T.A. Lebedkina; M.A. Lebyodkin
- Publisher
- Elsevier Science
- Year
- 2008
- Tongue
- English
- Weight
- 467 KB
- Volume
- 56
- Category
- Article
- ISSN
- 1359-6454
No coin nor oath required. For personal study only.
✦ Synopsis
The unstable plastic flow caused by the Portevin-Le Chatelier effect is studied experimentally. Non-local effects due to strain heterogeneity are addressed by comparing the statistical and multifractal properties of tension and compression deformation curves of an AlMg alloy. Power-law statistical distributions and multifractal scaling are found in certain experimental conditions, and provide a quantitative characterization of the plastic-flow intermittency. The analysis reveals distinct temporal patterns associated with stress serrations in tension and compression, reflecting distinct modes of the collective dislocation dynamics. In contrast, the onset of instability follows similar relationships in both loading conditions. This similarity justifies the conventional approach to modeling the loss of stability of a uniform plastic flow as a local property, governed by the homogenized behavior of the dislocation ensemble.
📜 SIMILAR VOLUMES
The effect of solute content and heat treatment on occurrence of the P-L effect were investigated in AI-Ag alloys. The activation energies estimated from values of the critical strains were nearly equal to that for solute migration in AI-MO alloys, which means that the P-L effects in AI-Ag alloys we
The influence of precipitation hardening on the characteristics of serrated yielding in an Al-IMg-Si alloy has been investigated. The critical strain at the onset of serrated yielding was increased by ageing and for ageing times longer than 6 hr at 180°C serrated yielding was not observed. The strai