Strain path change effect on dislocation microstructure of multicrystalline copper sheets

Abstract

In this study, coarse-grained copper sheets were subjected to tension-rolling and rolling-tension strain path sequences. In both cases, two different types of strain path change were studied: the tensile and rolling directions were parallel and normal to each other. TEM observations of deformed samples showed the typical dislocation structures for the prestraining paths in tension and rolling. Special microband features, not observed during prestrain, were found during the second strain path, whatever the sequence and type of strain path change. The microstructure observed during reloading is discussed in terms of the sequence and type of strain path change, parallel or normal. The frequency of appearance of microbands is discussed in terms of the activity of new slip systems, i.e. not active during the prestrain path and connected with the number of the active slip systems after reloading. The results from this study, obtained for coarse-grained multicrystalline copper sheets, are compared with previous ones for fine and medium-grained copper.

Temperature and deformation effect on the low and high angle grain boundary structure of a double forged pure tungsten

“…Moreover, the strain path history affects both the stored energy and the heterogeneities of the microstructure. Last but not least, the last step of the fabrication processes mainly affects the microstructure, which causes the difference in tensile properties in different directions [14,15].…”

Orientation dependence of the deformation microstructure in compressed aluminum

“…[3][4][5] have been investigated and attributed to interactions between the dislocation boundaries evolved during the first deformation step and dislocations from new slip systems activated after the strain path change. The occurrence of stress transients, as well as 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 2 electron microscopy studies [6][7][8][9], imply a reorganization of the dislocation boundaries following a strain path change.…”

Microstructure evolution of single crystal copper wires in cold drawing

“…In the previous research on the microstructure of copper deformed at room temperature, deformation twins almost have not ever been reported [7,8,10] . However, deformation twins can be observed sometimes in single crystal copper wires cold drawn at room temperature (Figure 7(b)).…”