Studies on the formability of Al-based metallic glasses/nanocomposites based on isochronal DSC analysis
Studies on the formability of Al-based metallic glasses/nanocomposites based on isochronal DSC analysis
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DOI：
10.1016/j.jnoncrysol.2010.07.023
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发表时间：
2010-09
影响因子：
3.5
通讯作者：
L. Zhuo;Tao Zhang
中科院分区：
文献类型：
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作者：
L. Zhuo;Tao Zhang
采用等时差示扫描量热法研究了Al_（86）Si_（0.5）Ni_（4.06）Co_（2.94）Y_（6Sc_（0.5））非晶合金的非晶形成能力，并与Al_（85）Ni_（50）Co_（2.94）Y_（80）非晶合金进行了对比。实验结果表明，Al_（86）Si_（0.5）Ni_（4.06）Co_（2.94）Y_（60）Sc_（0.5）合金的第一次晶化和第二次晶化之间的温度间隔增大（称为初级fcc-Al/玻璃区域），以及增大了金属间化合物成核和生长的第二激活能（Ep ~ 2）。Avrami指数的变化表明，初始晶化过程是一个快速的二维和三维扩散控制的成核和生长机制，整个过程受fcc-Al晶体生长的强烈控制。通过对合金成分原子迁移率的分析，认为通过适当的异种元素和同种元素共存，可以扩大初生fcc-Al/玻璃区，有利于制备更大尺寸的Al基金属玻璃或纳米复合材料。
The Al86Si0.5Ni4.06Co2.94Y6Sc0.5metallic glass of highly improved glass-forming ability (GFA) has been investigated by isochronal differential scanning calorimetry measurements, as well as the Al85Ni5Co2Y8for comparison. The experimental results indicate that the Al86Si0.5Ni4.06Co2.94Y6Sc0.5exhibits enlarged temperature interval between the first and second crystallization onsets (termed as primary fcc-Al/glass region), as well as enlarged second activation energy (Ep2) against the nucleation and the growth of intermetallic compounds besides fcc-Al. The variation of the Avrami exponent demonstrates that the primary crystallization process is a rapid two- and three-dimensional diffusion-controlled nucleation and growth mechanism initially, and the whole process is strongly controlled by the growth of fcc-Al crystals. According to the analysis on the basis of atomic mobility of alloy components, it demonstrates that the enlarged primary fcc-Al/glass region obtained through proper coexistence of dissimilar and similar elements would be in favor of preparing Al-based metallic glasses or nanocomposites in greater size.