Authors
Johann Petit, Danièle Wagner, Nicolas Ranc, Guillaume Montay, Manuel François,
Title
Comparison of different techniques for the monitoring of the Piobert-Lüders bands development
In
13th International Conference on Fracture (ICF13), Beijing 26-30 mai 2013
Volume
5
Pages
3797–3809
Year
2013
Indexed by
Abstract
In C-Mn and some low alloyed steels, the plastic deformation begins by a macroscopic heterogeneous strain which materializes into the propagation of a strain band along a tensile sample with a uniform cross-section. This band is named Lüders, or Piobert-Lüders, band and it is considered by some authors as a plastic wave. This particular strain localization, which goes through the length of the sample, is explained by an avalanche phenomenon which enables step by step to unfix the dislocations from their Cottrell’s atmosphere. However, although its effects are well enough known, one knows much less its causes. In this paper, the travel of the Lüders band is monitored thanks to several techniques based on different physical principles: optical (speckle interferometry), thermal (infrared pyrometry) and acoustic (acoustic emission). The position of the band, its inclination, its propagation speed and th e strain rate inside the band are the main points of comparison between each technique. They allow verifying some features about the propagation of the bands and giving some new assumptions about their formation and their development
Affiliations
Offprint