Revealing the atomistic nature of dislocation-precipitate interactions in Al-Cu alloys

I. Adlakha, P. Garg, K. N. Solanki

Research output: Contribution to journalArticlepeer-review

32 Scopus citations


Despite significant gains on understanding strengthening mechanisms in precipitate strengthened materials, such as aluminum alloys, there persists a sizeable gap in the atomistic understanding of how different precipitate types and their morphology along with dislocation character affects the hardening mechanisms. Toward this, the paper examines nature of precipitation strengthening behavior observed in the Al-Cu alloys using atomistic simulations. Specifically, the critical resolved shear stress is quantified across a wide range of dislocation-precipitate interactions scenarios for both θ′ and θ phase of Al2Cu. Overall, the simulations reveal that the dislocation character (edge or screw) plays a key role in determining the predominant hardening mechanism (shearing vs. Orowan looping) employed to overcome the θ′ Al2Cu precipitate. Furthermore, the critical shear stress and mechanism to overcome the precipitate is sensitivity to the position of the glide plane with respect to the precipitate and its orientation. Interestingly in our findings, the θ Al2Cu precipitate conventionally regarded as un-shearable particle was overcome by shear cutting mechanism for small equivalent precipitate radius, which agrees with recent TEM observations. These findings provide necessary information for the development of atomistically informed precipitate hardening models for the traditional continuum scale modeling efforts.

Original languageEnglish (US)
Pages (from-to)325-333
Number of pages9
JournalJournal of Alloys and Compounds
StatePublished - Aug 15 2019


  • Atomistic
  • Critical resolve shear stress
  • Dislocation
  • Precipitation hardening

ASJC Scopus subject areas

  • Mechanics of Materials
  • Mechanical Engineering
  • Metals and Alloys
  • Materials Chemistry


Dive into the research topics of 'Revealing the atomistic nature of dislocation-precipitate interactions in Al-Cu alloys'. Together they form a unique fingerprint.

Cite this