Calorimetric study of the crystallization kinetics of Cu47Ti33Zr11Ni8Si1 metallic glass

作     者：S. Venkataraman H. Hermann C. Mickel L. Schultz D. J. Sordelet J. Eckert 

作者机构：FG Physikalische Metallkunde FB 11 Material- und Geowissenschaften Technische Universität Darmstadt Petersenstraße 23 D-64287 Darmstadt Germany Leibniz-Institut für Festkörper- und Werkstoffforschung Dresden Helmholtzstraße 20 D-01069 Dresden Germany Material and Engineering Physics Program Ames Laboratory (USDOE) Iowa State University Ames Iowa 50014 USA 

出 版 物：《Physical Review B》 (Phys. Rev. B Condens. Matter Mater. Phys.)

年 卷 期：2007年第75卷第10期

页      面：104206-104206页

核心收录：

学科分类：0808[工学-电气工程] 0809[工学-电子科学与技术（可授工学、理学学位）] 07[理学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

摘      要：The isochronal and isothermal activation energies for the primary crystallization process of Cu47Ti33Zr11Ni8Si1 metallic glass powders subjected to varying thermal treatments have been evaluated by differential scanning calorimetry and determined using the Kissinger approach and the Johnson-Mehl-Avrami (JMA) analysis, respectively. The values of the differential Avrami exponent are also determined from the isothermal data. Assuming diffusion-controlled growth, it is shown that thermal treatment of the samples in the supercooled liquid region considerably influences the behavior of the nucleation rate during the crystallization process. Microstructural investigations indicate that the thermal treatment is accompanied by precipitation of fine nanocrystals in an amorphous matrix. The values for the activation energies determined by both the Kissinger approach and the JMA analysis are similar for the as-prepared powder, but a significant difference is found for the thermally treated powders. This discrepancy is explained on the basis of the fundamental assumptions made in the models. It will be shown that the Kissinger method fails if the differential Avrami exponent changes significantly during the transformation process.