A microplasticity analysis of shear band cracks in rolled 2024 aluminium alloy

Wing Bun Lee, Kang Cheung Chan

Research output: Journal article publicationJournal articleAcademic researchpeer-review

7 Citations (Scopus)

Abstract

Flow localization in the form of shear bands is an important part of the ductile fracture process. The propagation of shear-band cracks has been followed in the rolling of an annealed and an aged-hardened 2024 aluminium alloy respectively. Shear bands occurred in the alloy that had been aged-hardened prior to rolling but not in the one that had been annealed. There are two types of observed shear bands: grain-scale shear bands and sample-scale shear bands. The shear-band cracks were found to propagate along the directions of the sample-scale shear bands which often deviate from the maximum shear stress plane of 45°. While some grains allowed the cracks to pass through, some grains would stop the cracks from growing. A material based constitutive equation was used to predict the angle of the shear-band cracks and the prediction agreed well with the observed ones. The propagation of the shear-band cracks were found to be sensitive to the local variation of the crystallographic texture proportion. Both the microplasticity and continuum theories point out the importance of strain hardening rate as an important controlling factor in the occurrence of shear band cracks in textured polycrystals.
Original languageEnglish
Pages (from-to)207-221
Number of pages15
JournalInternational Journal of Fracture
Volume52
Issue number3
DOIs
Publication statusPublished - 1 Dec 1991

ASJC Scopus subject areas

  • Computational Mechanics
  • Modelling and Simulation
  • Mechanics of Materials

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