کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
1481790 | 1510479 | 2012 | 8 صفحه PDF | دانلود رایگان |
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.
► A recipe is proposed to determine activation energies for nucleation and growth.
► The recipe is more reliable and concise than commonly used methods.
► QN and QG for the crystallization of several amorphous alloys are obtained.
Journal: Journal of Non-Crystalline Solids - Volume 358, Issues 12–13, 1 July 2012, Pages 1417–1424