Nanosized Lead Inclusions in Aluminum-Magic Sizes and Aspect Ratios
Nanosized Lead Inclusions in Aluminum-Magic Sizes and Aspect Ratios
复制标题
铝中纳米级铅夹杂物的神奇尺寸和纵横比
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
T. Fujii
中科院分区：
文献类型：
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作者：
E. Johnson;A. Johansen;U. Dahmen;Shi Chen;T. Fujii
采用快速凝固和离子注入的方法制备了含有密集分布的纳米级铅沉淀相的铝铅合金。嵌入的沉淀物生长在平行立方体与铝基体对齐，他们有一个立方八面体的形状，从最小化的总界面能，和原子光滑的{111}和{100}方面。最小的沉淀物，小于约20纳米的尺寸，采用一系列的魔术尺寸确定的周期性极小值的残余应变能。在这个尺寸范围内，立方八面体边缘的能量变得显著。这导致沉淀物的纵横比的变化，使得较小的沉淀物较少被截断。将实验数据拟合到解析表达式，得到{100}和{111}界面能量之间的比值为1.15，边缘和{111}界面之间的能量比值为2.06。
Aluminum-lead alloys containing dense distributions of nanosized lead precipitates have been made by rapid solidification and ion implantation. Embedded precipitates grow in parallel-cube alignment with the aluminum matrix; they have a cuboctahedral shape resulting from a minimization of the total interface energy, and atomically smooth {111} and {100} facets. The smallest precipitates, less than about 20 nm in size, adopt a series of magic sizes determined by periodic minima in the residual strain energy. In this size range the energy of the cuboctahedral edges becomes significant. This leads to changes in the aspect ratio of the precipitates so that the smaller precipitates are less truncated. Fitting the experimental data to an analytical expression gives a value of 1.15 for the ratio between the {100} and {111} interface energies and a value of 2.06.a Pb for the ratio of energies between the edges and {111} interfaces.