Compressive flow behavior of Al-TiN multilayers at nanometer scale layer thickness

D. Bhattacharyya, N. A. Mara, P. Dickerson, R. G. Hoagland, A. Misra

Research output: Contribution to journalArticlepeer-review

107 Scopus citations

Abstract

The mechanical behavior of nanoscale Al-TiN multilayered composites was studied using micropillar compression experiments, which were compared with previously performed nanoindentation experiments, and the microstructure was investigated using scanning and transmission electron microscopy. It was found that at extremely small layer thicknesses (<5 nm) the nanoscale multilayers acquire remarkable hardness (∼6 GPa), high flow strengths (∼4.5 GPa maximum) and high compressive deformability (5-7% plastic strain). These high strengths were accompanied by extraordinarily high strain-hardening rates in the Al layers, which were of the order of 16-35 GPa (∼E/4-E/2) in "regime II" of the stress-strain curve of the compression tests in the 2-4 nm layered films and 5-9 GPa in the Al-18 nm-TiN-2 nm layered films, where Al layers deform plastically and TiN layers are deformed elastically. The high strengths and high work-hardening rates are discussed and analyzed using the concepts of dislocation motion and interactions within the confined nanoscale Al layers.

Original languageEnglish (US)
Pages (from-to)3804-3816
Number of pages13
JournalActa Materialia
Volume59
Issue number10
DOIs
StatePublished - Jun 2011

Bibliographical note

Funding Information:
The authors wish to thank J. K. Baldwin at LANL for assistance with magnetron sputtering of Al/TiN multilayers. The very fruitful discussions with Prof. J. P. Hirth and Prof. W. D. Nix are gratefully acknowledged. This work was funded by the Office of Basic Energy Sciences (BES) of the Office of Science, Department of Energy of the United States Government. The Center for Integrated Nanotechnologies, a BES user facility, is acknowledged for nanoindentation access through an approved user proposal with N. A. Mara.

Keywords

  • Compression test
  • Nanocomposite
  • Nanoindentation
  • Plastic deformation

Fingerprint

Dive into the research topics of 'Compressive flow behavior of Al-TiN multilayers at nanometer scale layer thickness'. Together they form a unique fingerprint.

Cite this