Solid state reactions in Al/Ni alternate foils induced by cold rolling and annealing
Solid state reactions in Al/Ni alternate foils induced by cold rolling and annealing
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DOI：
10.1016/s1359-6454(99)00040-3
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发表时间：
1999-04
期刊：
影响因子：
9.4
通讯作者：
L. Battezzati;P. Pappalepore;F. Durbiano;Isabella Gallino
中科院分区：
文献类型：
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作者：
L. Battezzati;P. Pappalepore;F. Durbiano;Isabella Gallino
由具有总成分Al 50 Ni 50和Al 66 Ni 34的交替箔制成的Al/Ni复合材料被轧制多达75次，在每个轧制道次之后折叠它们以恢复近似原始厚度。结果表明，复合材料的变形是由Ni和Al作为传递介质维持的。箔厚度的对数减少与轧制道次成比例。元素，特别是Ni，逐渐达到纳米晶体状态。没有可检测到的反应是由重复的共同变形引起的。复合材料中的反应发生在退火时。通过成核和生长在Al/Ni界面处获得的相序列，并通过X射线衍射、透射电子显微镜、扫描电子显微镜鉴定，再现了退火沉积多层膜和球磨粉末上发现的相序列：Al 3 Ni，Al 3 Ni 2，NiAl。所有的反应都被变形强烈激活，即它们在较低的温度下发生，如在差示扫描量热计中的连续加热实验所揭示的。整体的实验结果是一致的成核和生长的反应机制与晶界相互扩散的速率决定步骤。这一观点得到支持的扩散，晶粒生长，并在铝镍相的顺序的激活能的数据的集合进行比较。
Al/Ni composites made of alternate foils having overall composition Al50Ni50and Al66Ni34were rolled up to 75 times folding them after every rolling pass to restore approximately the original thickness. It was found that the deformation of the composite is sustained by the Ni with Al acting as transmitting medium. The logarithmic reduction of foil thickness scales with the number of rolling passes. A nanocrystalline state of the elements, particularly Ni, is progressively reached. No detectable reaction is caused by repeated co-deformation. Reactions in the composites occur on annealing. The sequence of phases obtained at Al/Ni interfaces via nucleation and growth, and identified by X-ray diffraction, transmission electron microscopy, scanning electron microscopy, reproduces that found on annealing deposited multilayers and ball-milled powders: Al3Ni, Al3Ni2, NiAl. All reactions are strongly activated by deformation, i.e. they occur at lower temperature as revealed by continuous heating experiments in a differential scanning calorimeter. The overall set of experimental results is consistent with reaction mechanisms of nucleation and growth with grain-boundary interdiffusion as the rate-determining step. This view is supported by comparison with a collection of data for the activation energy of diffusion, grain growth, and ordering in Al–Ni phases.