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Title: Experimental investigation of the ordering pathway in a Ni-33 at.%Cr alloy

The present study involves a detailed experimental investigation of the concurrent compositional clustering and long-range ordering tendencies in a Ni-33 at.%Cr alloy, carried out by coupling synchrotron-based X-ray diffraction (XRD), transmission electron microscopy (TEM), and atom probe tomography (APT). Synchrotron-based XRD results clearly exhibited progressively increasing lattice contraction in the matrix with increasing isothermal aging time, at 475 degrees C, eventually leading to the development of long-range ordering (LRO) of the Pt2Mo-type. Detailed TEM and APT investigations revealed that this LRO in the matrix is manifested in the form of nanometer-scale ordered domains, and the spatial distribution, size, morphology and compositional evolution of these domains have been carefully investigated. Here, the APT results also revealed the early stages of compositional clustering prior to the onset of long-range ordering in this alloy and such compositional clustering can potentially be correlated to the lattice contraction and previously proposed short-range ordering tendencies.
 [1] ;  [1] ;  [2] ;  [1] ;  [3] ;  [3] ;  [2] ;  [4] ;  [1]
  1. Univ. of North Texas, Denton, TX (United States)
  2. Colorado School of Mines, Golden, CO (United States)
  3. Korean Atomic Energy Research Institute, Daejeon (South Korea)
  4. Argonne National Lab. (ANL), Argonne, IL (United States)
Publication Date:
Grant/Contract Number:
AC02-06CH11357; 2011-01-K
Accepted Manuscript
Journal Name:
Acta Materialia
Additional Journal Information:
Journal Volume: 115; Journal Issue: C; Journal ID: ISSN 1359-6454
Research Org:
Argonne National Lab. (ANL), Argonne, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22), Scientific User Facilities Division; Korea Atomic Energy Research Institute (KAERI); USDOE
Country of Publication:
United States
36 MATERIALS SCIENCE; Ni-based superalloy; atomic ordering; orientation specific APT; synchrotron XRD
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1323588