Sparse modeling of space- and time-varying diffraction response of a progressively loaded aluminum alloy

Daniel Banco, Eric Miller, Matthew P. Miller, Armand Beaudoin

Research output: Contribution to journalArticlepeer-review


High energy X-ray diffraction data collected in situ during loading experiments permits probing of the crystal structure of a plastically deforming material sample. An elastoplastic deformation is associated with heterogeneity in both crystal orientation and lattice spacing—each manifesting as azimuthal broadening and radial broadening of diffraction peaks respectively. Quantifying the spreading effect is challenging, especially in cases where the sample has a granularity between that of a single crystal and fine grain or powder material. The approach developed in this paper begins by modeling the intensity signal in the vicinity of a Debye-Scherrer ring as a sparse, nonnegative superposition of Gaussian basis functions drawn from an over-complete dictionary. Processing automatically selects from the dictionary basis functions whose widths and amplitudes are representative of the data. The chosen basis functions are used to compute scalar measures of radial and azimuthal broadening for the set of diffraction peaks composing a Debye-Scherrer ring. To demonstrate the utility of the approach, we show that analysis of diffraction peak shape information from an aluminum alloy 7075 T651 (AA7075 T651) sample provides insight into the origin of material state that would have otherwise have been difficult if not impossible to extract using conventional methods. Furthermore, the extracted information revealed a deformation response linked to the processing history of the sample.

Original languageEnglish (US)
Pages (from-to)713-723
Number of pages11
JournalMaterials Characterization
StatePublished - Nov 2018


  • High-energy synchrotron radiation
  • Plasticity
  • Polycrystalline materials
  • Sparse coding
  • X-ray diffraction

ASJC Scopus subject areas

  • General Materials Science
  • Condensed Matter Physics
  • Mechanics of Materials
  • Mechanical Engineering


Dive into the research topics of 'Sparse modeling of space- and time-varying diffraction response of a progressively loaded aluminum alloy'. Together they form a unique fingerprint.

Cite this