The miniaturization of products requires the mass production of microparts. The microforming can
well meet this requirement. Due to the emergence of decreasing flow stress scale effect in the micro scale, the
traditional forming process and theory may fail. Based on the crystal plasticity theory, upsetting tests of micro
copper cylinders with different dimensions and grain sizes were simulated, and the decreasing flow stress scale effect
was studied and discussed. Results show that with the decrease of billet dimensions, the flow stress is gradually
decreased, and the decreasing flow stress scale effect is emerged; with the increase of grain size, the decreasing
flow stress scale effect is more remarkable. It can also be seen that the decreasing flow stress scale effect can be
well simulated with the crystal plasticity theory, and the necessary relevant information is provided for deeper
understanding on this scale effect, as well as the design of processes and die structures in the microforming.
SHEN Yu1 (申昱), YU Hu-ping1 (于沪平), DONG Xiang-huai1 (董湘怀), GUO Bin (郭斌)2
. Simulation and Discussion on the Decreasing Flow Stress Scale Effect[J]. Journal of Shanghai Jiaotong University(Science), 2012
, 17(3)
: 306
-311
.
DOI: 10.1007/s12204-012-1274-0
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