中文摘要：

设计开发了3套典型盒形件微拉深模具,分别为模具Ⅰ、模具Ⅱ、模具Ⅲ,将厚度分别为100,50和20μm的3种材料分别在常温、850和950℃的温度下进行热处理,将热处理后的板料放在3种模具中进行拉深成形,研究其最大拉深力和成形深度。研究发现,微成形过程的尺度效应很明显,最大成形力和成形深度会明显减小,且不能简单用宏观成形中的相似性和类比性进行计算和解释。通过归一化处理引入尺寸比例系数λ和厚度晶粒尺寸比t/D,发现λ能够更好地解释模具Ⅰ、Ⅱ相对较大尺寸微成形过程,模具Ⅲ成形过程只能通过引入厚度晶粒比t/D才能更好地解释微成形突变现象。

英文摘要：

Three sets of typical square cup dies for micro drawing named as Ⅰ,Ⅱ and Ⅲ were designed and developed.These materials with thickness of 100,50 and 20 μm were conducted by heat treatment at room temperature,850 ℃ and 950 ℃ respectively.Then,they were drawn in three dies,and the maximum drawing force and the maximum drawing depth were studied respectively.It is found that the scale effect is obvious during micro drawing process,and the maximum drawing force and the maximum drawing depth are decreasing sharply and cannot be explained and calculated by the similarity and analogy principle in macro forming.Therefore,the size ratio λ and thicknessgrain size ratio of t/D by normalized treatment are introduced,which demonstrates the relatively large size micro drawing phenomena produced byⅠ,Ⅱ dies and only by introducing the thickness grain size ratio of t/D can explain the mutation phenomenon produced by Ⅲ die.