摘要
通过在200℃恒载荷的高温变形实验,对厚度(t)为10～200μm的铝箔的应变速率与厚度的变化规律进行了研究.在t≥50μm时,随厚度的降低,变形速率增加,而在t<50μm时随厚度的降低,变形速率降低.根据实验结果,在t≥50μm时应变速率与厚度的关系符合幂率关系,其中的指数(α)大约在1～2之间,α依存于应力和晶粒大小.在t<50μm时应变速率与厚度的关系则受到晶粒减小和织构增强的强烈影响.对高温变形机制的考察表明,其变形受晶界滑移控制.在变形微观结构的观察中找到了晶界滑移的证据.
The relationship between the strain rate and the thickness （t） is investigated via creep test of thin AI foils with the thickness of 10-200μm under constant applied stress at 200 ℃. At t≥50μm, the strain rate is increased with decrease in thickness. However. at t〈50μm, the strain rate is decreased with decrease in thickness. According to the experimental results, a power-law dependence of strain rate on thickness can be obtained at t≥50μm. The power exponent a is in the range of 1 -2 and depends on the applied stress and the grain size. The relation- ship between the strain rate and the thickness is affected dramatically by the fine grain size and strong texture of the A1 foils with t〈50μm. The creep mechanism is found to he the grain boundary sliding, of which the experimental evidence is found in the microstructure observation.
出处
《南京大学学报（自然科学版）》
CAS
CSCD
北大核心
2009年第2期198-202,共5页
Journal of Nanjing University（Natural Science）
关键词
尺度效应
高温变形
微观结构
微机电系统
铝箔
size effect, high temperature deformation, microstructure, micro-electro-mechanical systems （MEMS）, AI foil
