Microstructure and texture evolution of cold drawing 〈110〉 single crystal copper

Abstract

By means of electron backscattering diffraction and transmission electron microscopy the microstructure and texture of drawn single crystal copper with initial orientation 110 parallel to axial direction have been investigated in the present work. In order to analyze the effect of initial orientation on microstructure and texture of drawn copper, the results of the drawn 110 single crystal copper wires have been compared with 100 and 111 single crystal copper wires. It is found that the grain subdivision of 110 single crystal is more evident than that of 100 and 111, and the textures consisting of 111 and 100 abruptly form in the drawn 110 single crystal. At high strains, due to shear strain, the distribution of fiber textures is imhomogenous along the radial direction of drawn 110 single crystal copper wires. 100 is near the surface and 111 is at the center. The microstructure results of drawn 110 single crystal show that at low strains, it can be characterized as two kinds of geometrically necessary boundaries with noncrystalline character. At medium strains, S bands can be observed. At high strains, lamellar boundaries form. Mean misorientation and average spacing of dislocation boundary are larger in drawn 110 single crystal, as compared with 111 and 100. In drawn 110 single crystal with high strains, the bimodal distribution forms at lower strains than in drawn 100 single crystal, which is because the dislocation boundaries with high angle are contributed by not only the boundary between 111 and 100 fiber textures but also the boundary in 111 or 100 texture. single crystal copper, cold drawing, texture, microstructure Citation: Chen J, Yan W, Li B, et al. Microstructure and texture evolution of cold drawing 110 single crystal copper. Sci China Tech Sci, 2011, 54: 1551 1559,

Microstructure and Texture of Hydrostatic Extrusion Deformed Ni Single Crystals and Polycrystal

“…The exception is HE-treated = 1.2 ⟨100⟩ Ni single crystal, where the initial orientation has been maintained in 51% by volume. The stability of the starting ⟨100⟩ orientation in FCC single crystals after deformation has also been observed in another type of deformation [17]. It can also be noted that by applying higher total strain on ⟨110⟩ single crystals the dominating ⟨111⟩ fibre breaks down to two components: ⟨100⟩ and ⟨235⟩.…”

Evolution of microstructure and texture of cold-drawn polycrystalline Ag with low stacking fault energy

“…Figure 3 shows the microstructure resulting from dislocation slip in drawn polycrystalline Ag with low SFE, indicating that there are dislocation cells and un-tangled discrete dislocations at low strains (Figures 3(a)-(c)), and GNBs at high strains (the white dotted line illustrates the GNBs in Figures 3(d)-(h)). Contrasting to other FCC metals with medium to high SFE investigated by Hansen and Huang et al [14,24], Li et al [25] and Chen et al [20,26], some obvious differences in drawn polycrystalline Ag with low SFE can be found out. First, the average width of cell walls is about 75 nm in the present cold drawn Ag at a strain of 0.28, but that is 20-30 nm in cold drawn copper at the same strain [20,26], indicating that the decrease in SFE will lead to the increase in the width of dislocation cell walls.…”

“…Contrasting to other FCC metals with medium to high SFE investigated by Hansen and Huang et al [14,24], Li et al [25] and Chen et al [20,26], some obvious differences in drawn polycrystalline Ag with low SFE can be found out. First, the average width of cell walls is about 75 nm in the present cold drawn Ag at a strain of 0.28, but that is 20-30 nm in cold drawn copper at the same strain [20,26], indicating that the decrease in SFE will lead to the increase in the width of dislocation cell walls. Second, for drawn polycrystalline Ag with low SFE, a large number of un-tangled discrete dislocations appear at low strains (Figure 3(b)) and the density of discrete dislocations increases with strains (Figures 3(b) and (c)).…”

“…Second, for drawn polycrystalline Ag with low SFE, a large number of un-tangled discrete dislocations appear at low strains (Figure 3(b)) and the density of discrete dislocations increases with strains (Figures 3(b) and (c)). However, it is difficult to observe the un-tangled discrete dislocations in FCC metals with medium to high SFE [14,20,24,25], which suggests that the planar slip is dominant, when cross slip and climb are suppressed in drawn polycrystalline Ag with low SFE. Last, previous studies [14,20,24,25] on FCC metals with medium or high SFE indicate that geometrically necessary boundaries (GNBs) form between regions of different strain patterns to accommodate the accompanying difference in lattice rotation.…”

“…In addition to the formation of these dislocation boundaries, the crystal will rotate during cold drawn process. For FCC metals with medium to high SFE, duplex fiber textures of <100> and <111> parallel to the axis direction form [16][17][18][19][20]. Therefore, it can be considered that <100> and <111> are stable crystal orientation for cold-drawn FCC metals with medium to high SFE.…”