Size Effect on Micro Tensile Test of Copper
Size Effect on Micro Tensile Test of Copper
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DOI：
10.4028/www.scientific.net/amr.264-265.108
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发表时间：
2011-06
期刊：
影响因子：
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通讯作者：
You Huang;Yao-Min Chang
中科院分区：
文献类型：
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作者：
You Huang;Yao-Min Chang
近十年来，金属微成形技术的研究引起了人们极大的兴趣。然而，无论是一种方法，也没有一个确切的微观力学性能已经很好地确定。因此，本研究进行了几个实验，以指出“尺寸效应”的影响。通过实验数据与相关参数的对比，可以发现材料在微观尺度下的力学特性，为了揭示材料在微观尺度下的力学特性，本文研究了试样尺寸和晶粒尺寸对铜材料微观拉伸试验的影响。首先，选取了五种不同厚度的微铜片作为实验材料。由于ASTM中制定的最小标准试件对于该微拉伸试验来说仍然太大，因此本研究决定将试样形状的样本量缩小到1/2。随着试件尺寸的减小，流变应力减小。该方法能够得到影响微拉伸试验流变应力的重要因素。其次，通过热处理制备不同晶粒度的样品。然后对这些不同粒度的试样进行了试验。根据实验结果，可以得到不同晶粒尺寸对流变应力的影响，进而得到试样尺寸与晶粒尺寸之间的力学行为变化规律。
There has been a significant research interest in metal micro-forming for the last ten years. However, neither a methodology nor an exact micro mechanical property has been well determined. Hence, several experiments are carried out in this research to point out the influence of “size effect”. Based on the comparison between the experimental data and relevant parameters, the material characteristics in micro scale can be found. In order to find the mechanical properties in micro scale, this study shows the effect of specimen size and grain size on the micro tensile test of copper material. Firstly, five copper micro-sheets with different thicknesses have been chosen as experimental materials. Since the minimum standard test piece formulated in ASTM is still too big for this micro tensile test, this study decided to shrink the sample size of specimen shape to 1/2 . Then the flow stress decreases with decreasing specimen size. This way is able to get the important factor which influence the flow stress on the micro tensile test. Secondly, these samples of different grain sizes are made by heat treatment. Then these samples of different grain sizes are used to conduct the experiment. According to the experimental result, the change of flow stress, which is influenced by various grain sizes, can be found. Finally, the change in the mechanical behavior between specimen size and grain size is obtained.