Microstructure Evolution and Grain Growth Kinetics in Annealed Nanocrystalline Chromium

Journal Article · Mon Jan 01 04:00:00 EST 2007 · Journal of Physical Chemistry

DOI:https://doi.org/10.1021/jp066993q· OSTI ID:931912

Chojnowski, Grzegorz ^[1]; Przenioslo, Radoslaw ^[1]; Sosnowska, Izabela ^[1]; Bukowski, Mirko ^[2]; Natter, Harald ^[2]; Hempelmann, Rolf ^[2]; Fitch, Andrew ^[3]; Urban, Volker S ^[4]

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1. Warsaw University
2. University of Saarbrucken, Saarbrucken, Germany
3. European Synchrotron Radiation Facility (ESRF)
4. ORNL

The kinetics of thermal evolution of the microstructure of nanocrystalline chromium (nano-Cr) has been studied by time-resolved synchrotron radiation techniques: high-resolution powder diffraction and small-angle X-ray scattering (SAXS). The as-prepared electrodeposited nano-Cr with average grain size of 27 nm shows the same bcc structure as {alpha}-Cr. The nano-Cr cubic lattice parameter thermal expansion is the same as that of reference polycrystalline {alpha}-Cr. Annealing of nano-Cr at temperatures above 400 C leads to a grain growth process with the final grain size not exceeding 125 nm even at a temperature of 700 C. The single power-law behavior is observed by SAXS in as-prepared nano-Cr changes during annealing above 400 C. In nano-Cr samples annealed at temperatures between 400 and 700 C, the low-q part of the SAXS signal shows a Porod-type behavior while the high-q part shows a power-law Q-{alpha} with the exponent {alpha} < 4. This effect is probably due to changes of the grain surface roughness during grain growth.

• Research Organization: Oak Ridge National Laboratory (ORNL)
• Sponsoring Organization: SC USDOE - Office of Science (SC)
• DOE Contract Number: AC05-00OR22725
• OSTI ID: 931912
• Journal Information: Journal of Physical Chemistry, Journal Name: Journal of Physical Chemistry Journal Issue: 111 Vol. 10.1021; ISSN JPCHAX; ISSN 0022-3654
• Country of Publication: United States
• Language: English

Related Subjects

43 PARTICLE ACCELERATORS
CHROMIUM
CUBIC LATTICES
GRAIN GROWTH
GRAIN SIZE
KINETICS
MICROSTRUCTURE
SYNCHROTRON RADIATION
THERMAL EXPANSION