Isothermal kinetics of mechanochemically and
thermally synthesized Ag from Ag2O
thermally synthesized Ag from Ag2O
(1. Department of Materials Science and Engineering, Shahid Bahonar University of Kerman, Kerman, Iran;
2. Department of Materials Science and Engineering, School of Engineering,
Shiraz University, Zand Avenue, Shiraz, Iran)
2. Department of Materials Science and Engineering, School of Engineering,
Shiraz University, Zand Avenue, Shiraz, Iran)
Abstract: The kinetics of isothermal reduction of Ag2O with graphite under argon atmosphere for a non-activated sample and mechanically activated sample was investigated. It is found that Johnson-Mehl-Avrami model appropriately explained the thermal and mechanochemical synthesis of Ag from Ag2O+ghraphite mixture. The process kinetics was investigated using the same approach for milled and unmilled samples. The results show that the Avrami exponent of mechanochemical reduction is higher than that of high temperature thermal reduction. Also, the mechanisms of nuclei growth in thermal and mechanochemical reduction are diffusion controlled and interface controlled, respectively.
Key words: isothermal kinetics; mechanochemical activation; thermal reduction; Johnson-Mehl-Avrami model; Ag