Microstructure and mechanical properties of Cu and Cu–Zn alloys produced by equal channel angular pressing

The effect of stacking fault energy on equilibrium grain size and tensile properties of nanostructured copper and copper–aluminum alloys processed by equal channel angular pressing

“…Recently, investigations into strain-induced grain refinement in Cu and Cu-based solid-solutions revealed that the grain refinement mechanisms changed from dislocation cell subdivision to twinning and twin fragmentation with decreasing SFE of the material [3][4][5][6][7][8]. Because the dislocation cell subdivision commonly is confined to a microstructural scale of submicrometer or above it produces only a limited grain refinement [3,[7][8][9].…”

“…Because the dislocation cell subdivision commonly is confined to a microstructural scale of submicrometer or above it produces only a limited grain refinement [3,[7][8][9]. By contrast, deformation twinning and twin fragmentation can refine the grain size (e.g.…”

Influence of alloying with hafnium on the microstructure, texture, and properties of Cu–Cr alloy after equal channel angular pressing

“…The ductility measured in terms of elongation at fracture (EL) decreased in both alloys after ECAP to approximately the same values of EL = 15-16 %, while the UTS in the ternary alloy was 1.3 times higher than that in the Cu-0.7 % Cr alloy. The relatively ''high'' ductility in the ternary alloy can be associated with larger fraction of high angle boundaries (HAB) [30,31] and weaker texture caused by Hf addition and increase in fraction of HAB [32,33]. The post-ECAP aging at 450°C for 1 h leads to additional strengthening up to UTS = 462 and 677 MPa for Cu-0.7 % Cr and Cu-0.7 % Cr-0.9 % Hf alloys, respectively.…”

Grain refinement in a Cu–Cr–Zr alloy during multidirectional forging

“…The strength of copper can be significantly increased by cold working [3][4][5], grain refinement [6][7][8][9][10][11], and the precipitation of nanoscale dispersoids [2,[11][12][13][14][15]. However, strengthening leads to a pronounced decrease in the electrical conductivity, due to increase in the dislocation density, grain boundaries, dispersoids, and solutes, which increase the scattering of conducting electrons [1].…”

“…Recently, many techniques of severe plastic working, such as accumulative roll-bonding [11], equal channel angular pressing [7][8][9][10]16,17,[28][29][30][31] and high pressure torsion [31][32][33], were applied to produce UFG structure in Cu-Cr-Zr alloys. It was shown that the high pressure torsion is the most effective technique in refining the grains and producing the large fraction of nanoscale grains after relatively small strains, whereas the equal channel angular pressing leads to only a partial UFG structure even after a cumulative true strain of ε$16 [7][8][9][10]16,17,[28][29][30][31]. There was no attempt to use multidirectional forging (MDF) for the grain refinement of Cu-Cr-Zr alloys despite the fact that this technique was highly efficient in producing UFG structure in copper at both room and intermediate temperatures [34,35].…”