The deformation and work hardening behaviour of a SPD processed Al-5Cu alloy

Abstract

An Al-5 wt.% Cu alloy supersaturated with Cu in solid solution was subjected to equal channel angular pressing (ECAP). The microstructural evolution was systematically investigated by backscattered electron (BSE) imaging, electron backscatter diffraction (EBSD) and transmission electron microscopy (TEM). It is revealed that a bimodal grain structure composed of coarse micron-sized grains and submicron-sized grains was developed after four passes of ECAP. Tensile testing showed that a high ultimate tensile strength of ~500 MPa, a high elongation to failure of ~28% and a uniform elongation of ~5% were achieved simultaneously. The deformation behaviour and the grain structure evolution during ECAP, the strengthening mechanisms of the as-deformed material, and especially, the role played by a high content of Cu have been discussed.

Quantifying the grain boundary segregation strengthening induced by post-ECAP aging in an Al-5Cu alloy

“…In the present work, the aim has been to further explore the strengthening mechanisms of the HOA phenomenon in SPD processed alloys, and thus post-ECAP aging treatments at low temperatures have been conducted on a bimodal structured Al-5wt.% Cu alloy [34] produced by room temperature ECAP. Systematic investigations on the evolution of grain size, dislocation density, solid solution level of Cu and precipitation of Al-Cu precipitates during post-ECAP aging have been done.…”

Formation of Σ3{110} incoherent twin boundaries through geometrically necessary boundaries in an Al-8Zn alloy subjected to one pass of equal channel angular pressing

“…A main focus has been put on the grain refinement mechanism and mechanical properties of the UFG materials [26][27][28][29], while the fundamental study on the deformation behavior has been mostly based on single crystals of low alloyed Al alloys [30,31]. In this paper, we report that a significant fraction of Σ3{110} ITBs could form by a special deformation mechanism in an Al-8Zn alloy deformed by conventional ECAP (strain rate, ~2 × 10…”

Microstructure‐Property Relations in the Tensile Behavior of Bimodal Nanostructured Metals

“…Except the aforementioned toughening mechanisms, Lee et al [15] further investigated the bimodal NS Al-Mg alloy and found that the CG inclusions can restrain the crack propagation: 1) by crack deflecting and branching and 2) by debonding. Jia et al [16] investigated the bimodal NS Al-Cu alloy and uncovered that the coarse grains Bimodal nanostructured (NS) metals realize the superior strength due to the strengthening of nanograined (NG) matrix, whereas their high ductility arises from the toughening of coarse-grained (CG) inclusions. Their overall strength and ductility can be influenced by 1) the fracture properties of CG and NG phases, 2) the distribution of CG inclusions, and 3) interfaces.…”

“…Meanwhile, the CG inclusions lead to the deeper dimples which conduce to an increase in the failure strain. [16] Equally intriguing, the CG inclusions contribute to improving work hardening and thus lead to both crack deflecting and blunting in bimodal NS Ti-Al-V alloy. [17] Sim et al [18] verified that the high dislocation accumulation capability of coarse grains can lead to the extended work hardening, whereas the CG inclusions ensure a large-scale dislocation sliding, resulting in the better ductility of the bimodal NS Ti-Al-Nb alloy.…”

“…Except the aforementioned toughening mechanisms, Lee et al further investigated the bimodal NS Al–Mg alloy and found that the CG inclusions can restrain the crack propagation: 1) by crack deflecting and branching and 2) by debonding. Jia et al investigated the bimodal NS Al–Cu alloy and uncovered that the coarse grains provide ample space for dislocation accumulation and thus enhance the work hardening. Meanwhile, the CG inclusions lead to the deeper dimples which conduce to an increase in the failure strain .…”