Science at the interface : grain boundaries in nanocrystalline metals.

Technical Report · Tue Sep 01 04:00:00 EDT 2009

DOI:https://doi.org/10.2172/974872· OSTI ID:974872

Rodriguez, Mark Andrew; Follstaedt, David Martin; Knapp, James Arthur; Brewer, Luke N; Holm, Elizabeth Ann; Foiles, Stephen Martin; Hattar, Khalid M; Clark, Blythe B; Olmsted, David L; Medlin, Douglas L

Interfaces are a critical determinant of the full range of materials properties, especially at the nanoscale. Computational and experimental methods developed a comprehensive understanding of nanograin evolution based on a fundamental understanding of internal interfaces in nanocrystalline nickel. It has recently been shown that nanocrystals with a bi-modal grain-size distribution possess a unique combination of high-strength, ductility and wear-resistance. We performed a combined experimental and theoretical investigation of the structure and motion of internal interfaces in nanograined metal and the resulting grain evolution. The properties of grain boundaries are computed for an unprecedented range of boundaries. The presence of roughening transitions in grain boundaries is explored and related to dramatic changes in boundary mobility. Experimental observations show that abnormal grain growth in nanograined materials is unlike conventional scale material in both the level of defects and the formation of unfavored phases. Molecular dynamics simulations address the origins of some of these phenomena.

• Research Organization: Sandia National Laboratories
• Sponsoring Organization: USDOE
• DOE Contract Number: AC04-94AL85000
• OSTI ID: 974872
• Report Number(s): SAND2009-5751
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
77 NANOSCIENCE AND NANOTECHNOLOGY
GRAIN BOUNDARIES
GRAIN GROWTH
GRAIN SIZE
INTERFACES
MOLECULAR DYNAMICS METHOD
NANOSTRUCTURES
NICKEL
Nanocrystals.
Nanostructure materials-Analysis.
Nanostructures.
WEAR RESISTANCE