Determination of activation energies for nucleation and growth from isothermal differential scanning calorimetry data

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• 作者：Yi-Hui Jiang ; Feng Liu ; ^{liufeng@nwpu.edu.cn} ; Shao-Jie Song ; Bao Sun
• 关键词：Isothermal ; Activation energy ; Nucleation ; Growth
• 刊名：Journal of Non-Crystalline Solids
• 出版年：2012
• 期刊代码：50_00223093
• 类别：ms
• 出版时间：1 July, 2012
• 卷：358
• 期：12-13
• 页码：1417-1424
• 文件大小：823 K

摘要

Differential scanning calorimetry (DSC) is usually adopted to analyze solid-state phase transformation incorporating nucleation, growth and impingement. Then, for isothermal transformation, time-dependent Avrami exponent and overall effective activation energy can always be deduced using recipes, which are derived from an analytical phase transformation model. On this basis, a concise and reliable approach to determine time-independent activation energies for nucleation and growth is proposed. Numerical calculations have demonstrated that the new approach is sufficiently precise under different conditions of transformation (e.g. nucleation: mixed nucleation and Avrami nucleation; growth: interface-controlled growth and diffusion-controlled growth; impingement: randomly nuclei dispersed, anisotropic growth and non-random nuclei distributions). Application of the approach in crystallization of Zr₅₅Cu₃₀Al₁₀Ni₅, Zr₅₀Al₁₀Ni₄₀ and Cu₄₆Zr₄₅Al₇Y₂ bulk amorphous alloys as measured by isothermal DSC was performed.