处于介观尺度的材料的塑性变形行为不同于通常的宏观范围的材料，存在尺度效应。而且其变形也不同于微观尺度的材料[1]。研究处于介观尺度材料的塑性变形的重要意义在于，为微成形的基本成形规律的研究和工艺技术的发展铺平道路。通过在200C恒载荷的高温变形实验，研究厚度为10～350微米的铝合金箔的等温塑性变形行为。研究铝箔的厚度和晶粒大小对高温变形速率的影响规律。通过透射电子显微镜的观察可以发现在晶界旁存在亚晶界。用t/d参量能很好的描述塑变的尺度效应，随着t/d的减小，应变速率增大。t/d对应力指数也具有影响作用。得到一个经验的公式来描述应变速率和t/d的关系，用此公式能较好地模拟应力指数随t/d的变化。
It is found that the plastic deformation behavior of the materials in meso-scale is different from that in macro scale, also that in micro scale. The importance of studying the high temperature deformation behavior of those materials is in that it paves the ways for basic forming discipline of microforming and developing microforming technology. Constant applied stress creep experiments at 200C of aluminum alloy thin foils with the thickness of 10～350m are carried out. The effect of the thickness and the grain size to the strain rate is studied. Subgrains are found near the grain boundary under the observation by Transaction Electronic Microscopy. The results show that using the parameter of t/d, the size effect of deforming can be better summarized. The strain rate is fast when t/d is reduced. It is found that the parameter of t/d has affected to the stress exponent. An equation is obtained to correlate the strain rate with t/d. The relationship between the stress exponent and t/d simulated by the equation is perfectly correspondent to the experimental data.
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