Header menu link for other important links
X
Ni tracer diffusion in CoCrFeNi and CoCrFeMnNi high entropy alloys
Published in Elsevier Ltd
2016
Volume: 688
   
Pages: 994 - 1001
Abstract
High entropy alloys (HEAs) are multicomponent alloys in equiatomic or nearly equiatomic composition. Anticipated sluggish atomic diffusion is reported to be one of the core effects in HEAs which is presumably responsible for their many unique properties. For the first time, in the present study, tracer (Ni) diffusion in CoCrFeNi and CoCrFeMnNi alloys is measured by the radiotracer technique in the temperature range of 1073–1373 K using the 63 Ni isotope. Chemically homogeneous alloys of equiatomic composition were prepared by a vacuum arc melting route. The microstructure and phase stability of the alloys in the given temperature range is confirmed by differential thermal analysis and X-ray diffraction. Ni diffusion in both CoCrFeNi and CoCrFeMnNi alloys is found to follow Arrhenius behavior. When plotted against the homologous temperature, a tendency to a successive slow down of the tracer diffusion rate with an increased number of components in equiatomic alloys is unambiguously established. Both the entropy term as well as the energy barriers is revealed to contribute to this trend. The current results indicate that diffusion in HEAs cannot a priori be considered as sluggish. © 2016 Elsevier B.V.
About the journal
JournalData powered by TypesetJournal of Alloys and Compounds
PublisherData powered by TypesetElsevier Ltd
ISSN09258388
Open AccessNo
Concepts (16)
  •  related image
    Differential thermal analysis
  •  related image
    Entropy
  •  related image
    Nickel
  •  related image
    Point defects
  •  related image
    Thermoanalysis
  •  related image
    Vacuum applications
  •  related image
    X ray diffraction
  •  related image
    CORRELATION FACTORS
  •  related image
    EQUIATOMIC COMPOSITION
  •  related image
    HIGH ENTROPY ALLOYS
  •  related image
    Homologous temperature
  •  related image
    MULTI-COMPONENT ALLOY
  •  related image
    Number of components
  •  related image
    RADIOTRACER TECHNIQUES
  •  related image
    Tracer diffusion
  •  related image
    Diffusion