Huifen CHAI Zheng RUAN Quncheng FAN Dept.of Materials Science and Engineering
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Xi'an Jiaotong University
,
Xi'an
,
710049
,
China
材料科学技术（英）
The prestrained metals show substantial asymmetry between tension and compression in addition to the softening under cyclic loading, thus the cyclic creep takes place at a load-control test. The soft- ening reflects the decrease in density of dislocation and total internal stress, and the creep implies the asymmetry in back stress between tension and compression, The mechanical behaviour of the soft- ening is similar for materials with different slip modes, but their features of creep differ significantly. The creep of planar slip Cu-Zn alloy exhibits“explosively”, while that of wavy slip Cu and low car- bon steel occurs continuously and slowly. The explanation of creep behaviour via the internal dislo- cation structure was presented in this paper. According to asymmetw behaviour, it can be concluded that the internal processes of softehing also strongly depend on the slip mode. In addition, under high stress amplitude the opposite asymmetries take place for Cu and Cu-Zn alloy, it indicates that asymmetric back stresses developed in pretension have been eliminated even though the density and the configuration of dislocations have not reached equilibrium.
关键词:
internal stress
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