Multi-pass Equal Channel Angular Pressing Research Articles

Obtaining Heterogeneous Microstructure and Enhanced Mechanical Properties in ECAP-Processed AZ61 Alloys via Single-Pass Rolling with Increased Rolling Reduction

Material design and preparation based on constructing heterogeneous microstructures can break the conventional performance limitations of fine-grained magnesium alloys. In this study, AZ61 alloys processed via multi-pass equal channel angular pressing (ECAP) were subjected to single-pass rolling (SPR) with increased rolling reductions. The effect of rolling reduction on the formation of heterogeneous microstructure and the mechanical properties of the alloy was investigated. Microstructural examinations revealed that a heterogeneous microstructure was formed in the alloy at varied rolling reductions, but the desired heterostructure with higher fine grain contents could only be achieved at increased rolling reduction. This was mainly due to the fact that the alloy underwent partial dynamic recrystallization (PDRX) under SPR, and PDRX more easily occurred with higher rolling reduction. The tensile test results showed that with increased rolling reduction, the strength of the alloy first increased and then decreased slightly, with the ductility steadily increasing. Improved mechanical properties were achieved in the alloy rolled at increased rolling reductions owing to the heterogeneous microstructure with a greater content of fine grains.

Effects of broken β-Mg17Al12 and non-uniform Mg2Pb particles introduced by EX-ECAP on microstructure and mechanical properties of Mg–Pb-9.2Al-0.8B alloys

Mg–Pb-9.2Al-0.8B alloy faces a significant strength-toughness balance problem in applications. To address this challenge, severe plastic deformation was applied to the alloy by combining traditional extrusion with multi-pass equal channel angular pressing (EX-ECAP). The research delves into the microstructural evolution (including broken β-Mg17Al12 and non-uniform Mg2Pb particles) and its effects on the strengthening mechanisms. The synergistic effects of grain boundary strengthening due to grain refinement, Orowan strengthening, geometrically necessary dislocation strengthening, and coefficient of thermal expansion strengthening collectively enhance the tensile strength and ductility, balancing the strength and toughness. The results showed an impressive ultimate tensile strength of 386.1 MPa, which is 2.33 times that of the as-cast alloy. The altered fracture morphology clearly indicated a transformation from brittle to brittle-ductile fracture mode. During the deformation process, the activation of dislocations, atomic-scale ripples, minor lattice distortions, and kink bands enhance the macroscopic flexibility. The introduction of EX-ECAP presents new opportunities for manufacturing high-performance Mg–Pb-9.2Al-0.8B alloy through integrated deformation techniques.

Enhanced yield stress and reduced elastic modulus of metastable β Ti–Nb alloys deformed by equal channel angular pressing attributed to the Synergistic effect of deformation mechanisms

This work aims to obtain Ti–Nb alloys with a high yield stress, good plasticity, and low elastic modulus. To this end, metastable β Ti–Nb alloys were subjected to multipass equal channel angular pressing (ECAP) deformation at room temperature, and a thorough investigation of their microstructure evolution, deformation mechanisms, and strengthening/toughening mechanisms was conducted through X-ray diffraction, transmission electron microscopy, electron backscatter diffraction, and tensile tests. In the initial deformation stages, multiple deformation mechanisms are observed, including dislocation slip, {332} <113> twinning, stress-induced martensite (SIM) α″-phase, {112} <111> twinning, and stress-induced ω-phase. However, as the strain accumulates, the ω-phase disappears, the volume fraction of the SIM α″-phase gradually decreases, and the dominant deformation mechanism changes to dislocation slip and {332} <113> twinning. The ECAP deformation results in a complex-network microstructure and the precipitation of the nanoscale SIM α″-phase, which leads to the twinning-induced plasticity (TWIP) and transformation-induced plasticity (TRIP) effects. As a consequence, the Ti–Nb alloy simultaneously exhibits a high yield stress and a good plasticity. Furthermore, the high-density dislocations and interfaces generated by the ECAP deformation reduce the stability of the β-phase, and the introduced nanopores cause a decrease in density, resulting in a decrease in the elastic modulus of the alloy.

Effect of equal-channel angular pressing on microstructure, aging kinetics and impact behavior in a 7075 aluminum alloy

Among the precipitation hardenable 7xxx series aluminum alloys, AA7075 alloys (one of the most important engineering alloys) due to their low density (lightweight), high toughness and strength, and enhanced fatigue behavior have been used over the years in aerospace, aircraft, automotive, construction and marine applications. In the present study, the influence of the artificial aging through conventional heat treatment (i.e., precipitation hardening) and the thermomechanical treatment (equal-channel angular pressing (ECAP) + post-ECAP aging) on the quasi-static tensile, impact toughness and precipitation behavior as well as on the microstructure of an AA7075 alloy is investigated systematically. The results indicate that the ECAP process as well as post-ECAP aging result in considerably increased strength and hardness of the AA7075 alloys because of the superimposed effects of grain boundary strengthening (Hall-Petch relation), strain hardening (by means of the increased dislocation density) and precipitation hardening (due to the fine precipitates formed in Al matrix). Multi-pass ECAP processing has been found to result in a considerable decrease of the impact toughness (from 15.3 J·cm−2 to 7.6 J·cm−2) associated with the failure mode (i.e., ductile-to-brittle transition) of the AA7075 alloys, whereas the artificial peak aging leads to a marked improvement (∼67 %) in the impact toughness in ECAPed conditions. Moreover, the ECAP process noticeably accelerates the precipitation kinetics of AA7075 alloys: The peak aging time in the ECAPed alloy is reduced significantly – from 30 h to 4 h. The results of the present study provide a deeper understanding of the combination of ECAP and heat treatment, and their effect on the fracture mode and toughness under impact loading, the aging kinetics and the microstructural evolution of an AA7075 alloy.

Microstructure and properties of biodegradable Zn-0.8Mn-0.5Cu-0.2Sr alloys processed by ECAP

In recent years, Zn alloys had been regarded as biomedical materials with good biocompatibility and biodegradability. However, the mechanical properties of Zn alloys were often not sufficient for the ideal orthopedic internal fixation implant. In order to improve the comprehensive mechanical properties of Zn alloys by strengthening and toughening, equal channel angular pressing (ECAP) method and Bc route were applied to process Zn-0.8Mn-0.5Cu-0.2 Sr alloys. Meanwhile, the effects of multi-pass ECAP on mechanical properties, corrosion behavior and microstructure were systematically investigated. As a result, ECAP could significantly refine the grain sizes of the as-cast Zn-0.8Mn-0.5Cu-0.2 Sr alloys. Only after 2 passes, the average grain sizes of the Zn-0.8Mn-0.5Cu-0.2 Sr alloy could be refined from 54.04 μm in as-cast to 1.20 ± 0.76 μm. In addition, the increase of ECAP passes promoted the precipitation of MnZn13 phase and reduced texture strength, which affected the strength and ductility. The UTS of the 2 P and 4 P alloys were 337.6 MPa and 320.4 MPa, respectively. And as ECAP passes increased from 2 to 8, the EL gradually increased from 24.9% to 46.3%. After ECAP, the corrosion rates of the Zn-0.8Mn-0.5Cu-0.2 Sr alloys increased. The corrosion rates of the 2 P and 4 P alloys measured by the weight loss method were about 0.022 mm/year and 0.019 mm/year. Thus, Zn-0.8Mn-0.5Cu-0.2 Sr alloy was expected to be a promising biodegradable material. Meanwhile, ECAP could be an effective avenue to achieve high comprehensive mechanical properties and suitable corrosion rates.

Evolution of microstructure, macrotexture and mechanical properties of high strength biomedical TA4 pure titanium during multi-pass ECAP

The application of equal-channel angular pressing (ECAP) to TA4 pure titanium (Ti) results in a fine-grained microstructure. This technique presents an substitute for alloying, delivering enhanced mechanical properties without reducing biocompatibility and corrosion resistance. This study employs scanning electron microscopy (SEM), X-ray diffractometry (XRD), and transmission electron microscopy (TEM) to explore the microstructure evolution and the toughening mechanism of TA4 pure Ti after deformation. ECAP performed at 573 K endows TA4 pure Ti with a uniformly fine-grained microstructure, leading to a significant enhancement in its mechanical properties, exemplified by a yield strength of ∼731.9 ± 2.7 MPa and an elongation of ∼30.8± 1.3 %. While the {0001} basal slip primarily governs the ECAP deformation, the non-basal slip plays an increasingly important role with the increase of passes. The increase of yield strength can be attributed to grain refinement and the modification of the {0001} basal texture. Meanwhile, the improvement of plasticity is related to the strengthening of the {101‾ 0} prismatic texture. These findings offer fresh insights and methodologies for the design and manufacture of high-performance biomedical pure Ti.

Investigation of Severe Plastic Deformation Effects on Magnesium RZ5 Alloy Sheets Using a Modified Multi-Pass Equal Channel Angular Pressing (ECAP) Technique.

The present study investigates the effects of multiple passes of equal channel angular pressing (ECAP) on magnesium alloy sheets with the assistance of an Inconel plunger along with a die setup having a channel angle of 120° and corner angle of 10° operating at a temperature of 200 °C followed by the required heat treatment processes. The microstructural analysis of the sheet samples at various stages of the multi-pass hot ECAP has shown evidence of ultrafine grain refinement (UFG) due to the occurrence of severe plastic deformation. X-ray diffraction analysis has also exhibited the presence of phases like MgZn and CeZn3 which is supposedly responsible for the enhancement of the mechanical properties. As a result, the room temperature tensile and compressive strengths have improved by 6.12% and 6.63%, respectively, after the second pass, and 11.56% and 15.64%, respectively, after the fourth pass of ECAP. Additionally, the hardness of the sheets has increased by 6.49% and 16.64% after the second and fourth pass of hot ECAP, respectively, mainly attributed to the drastic decrease in grain size from 164 μm to 12 μm within four ECAP passes, all these with a negligible change in ductility. This success in the thermomechanical processing of Mg-RZ5 alloy sheets using a die channel angle of 120° with a minimal number of passes of hot ECAP under a controlled equivalent strain, further opens doors for incorporating optimizations and/or additional aspects so as to achieve even better grain refinements, and consequently, mechanical strength improvements thereby catering to the industrial needs of aerospace and construction areas.

Achieving ultrahigh specific strength of an ultrafine grained Mg–9Li–1Al alloy via the combined processing of ECAP with repeated annealing and rolling

A super-high strength Mg–9Li–1Al (LA91) alloy with ultimate tensile strength (UTS) of 312 MPa and specific strength of ∼215 kNmkg−1 was successfully achieved via a combined processing of multi-pass equal-channel angular pressing (ECAP) with repeated annealing and room temperature (RT) rolling. Significant grain refinement after ECAP led to the formation of ultrafine-grain (UFG) α-Mg phase with grain size of ∼350 nm. Further refinement of the α-Mg grains reaching ∼200 nm was achieved by further repeated annealing and RT-rolling with high dislocation density. The formation of strong basal texture of the α-Mg phase of the combined-processed alloy also contributed to the achieved excellent strength-ductility synergy. The 1 wt% Al (aluminum) in the Mg–Li dual-phase matrix acted as a high-efficient strengthening element, and was the major contributory factor to the 48% improved specific strength of the alloy compared to the UFG Mg–9Li binary alloy in our former study. The Al element distributing throughout the alloy phases without segregation contributed to the enhanced refinement of the α-Mg grains during the combined processing and improved strain-hardening rate during the tension plastic deformation, allowing for the achievement of a high strength of the LA91 alloy.

Microstructure, texture, and instability during superplastic deformation of ECAP-treated AZ31 Mg alloy

An ultrafine-grained AZ31 Mg alloy processed through multipass equal channel angular pressing (ECAP) achieved 5 and 0.9 µm mean grain sizes after two and four passes, respectively. The deformation behaviour of the alloy was studied through tensile testing at high temperatures. A 410% superplastic elongation was achieved at 250°C during the tensile deformation of the four-pass-processed alloy. The Haehner criterion allowed the prediction of the stable uniform deformation of the alloy. The strain rate sensitivity of 0.38 and equiaxed microstructure suggested grain boundary sliding as the rate-controlling mechanism. The slip system’s contribution to superplasticity was discussed using related Schmid factors. Slip activity prevalence at high strains induced a texture-strengthening effect and allowed low-angle grain boundary formation at high strains.

Corrosion-fatigue resistance of ultrafine grain commercially pure titanium in simulated body fluid

Commercially pure titanium (CP-Ti) due to excellent biocompatibility and high specific strength is known as a metallic biomaterial and is widely utilized in medical applications as implant material. Because of low strength of CP-Ti as compared to other bio-metals, it has been proved in literatures that applying equal channel angular pressing (ECAP) process can be useful to enhancement of mechanical and metallurgical properties of CP-Ti by improvement of initial microstructure to ultrafine grained (UFG). Implant in human body is attacked from cyclic fatigue loads and corrosion, simultaneous. Hence, aim of this study is examination of corrosion-fatigue resistance of CP-Ti before and after introducing ECAP in simulated body fluid (SBF) as a saline solution close to blood plasma. In this study, multi-pass ECAP is conducted on CP-Ti at room temperature and then the axial fatigue test is performed in SBF environment with temperature 37 °C. The comparison of stress-cycle curves demonstrated that corrosion-fatigue resistance of ECAPed CP-Ti is extremely higher than initial annealed one. Moreover, it was observed that by increasing the pass number of ECAP, corrosion-fatigue resistance improves significantly. Furthermore, these results are compared to fatigue behavior of CP-Ti in air environment. The results show that corrosion-fatigue resistance of unECAPed and ECAPed CP-Ti in SBF is slightly lower than fatigue ones in air. According to the results of this experimental research, it is concluded that UFG CP-Ti has an awesome corrosion-fatigue resistance in human body and it is very suitable for utilizing as material of implants.

Tension-compression asymmetry of quadruple CuCoNiBe alloys processed by high-temperature multi-pass equal channel angular pressing (ECAP)

Abstract Among copper alloys, the precipitation (age) hardening quadruple CuCoNiBe alloys due to their superior mechanical properties in terms of the highest strength and elasticity achieved by peak aging have been used over the years in a wide range of industrial applications including aircrafts, coil systems, blast-proof materials, and molding dies. Combined thermomechanical treatment (i.e., equal channel angular pressing [ECAP] processing followed by post-ECAP aging) can result in a further enhancement of the strength of CuCoNiBe alloys due to the grain refinement and the formation of fine precipitates from α-Cu supersaturated solid solution. In this study, for the first time, the effect of severe plastic deformation by ECAP processing on the mechanical behavior of CuCoNiBe alloys is discussed thoroughly based on the material responses to tensile and compressive loading conditions. The results show that, besides a considerable strength enhancement, ECAP processing leads to a strong tension-compression asymmetry and significantly accelerated precipitation kinetics in CuCoNiBe alloys.

A high strength and ductility Zn–Cu–Mg alloy achieved by bandlike distribution of ultra-fine CuZn5 and Mg2Zn11 particles

Banded structure with alternately arranged ultra-fine η-Zn + Mg2Zn11 bands and ultra-fine η-Zn + CuZn5 bands was obtained in Zn–3Cu–1Mg (wt.%) alloy after multi-pass equal channel angular pressing (ECAP). Owing to the effective heterogeneous deformation-induced (HDI) strengthening and hardening from soft η-Zn + CuZn5 and hard η-Zn + Mg2Zn11 domains, the ECAP alloys exhibited outstanding mechanical properties with ultimate tensile strength of 388–415 MPa, and fracture elongation of 29.2–63.0%.

Improving microstructure and corrosion resistance of LPSO-containing Mg–Y–Zn–Mn alloy through ECAP integrated with prior solution treatment

Unique Mg-RE (rare earth) alloys with long-period stacking ordered (LPSO) structures have attracted extensive attention for their excellent mechanical properties and bright prospects. Thus it is urgent to improve their corrosion resistance simultaneously. The present work focused on the improvement of microstructure and corrosion behaviours in new Mg-2.2Y-1.1Zn-0.4Mn (wt. %) alloys with mixed LPSO phases through warm equal-channel angular pressing (ECAP) integrated with prior solution treatment (ST). The results show that the multi-pass ECAP process optimizes the grain size and distribution of mixed LPSO phases, which improves the corrosion resistance of the alloy. During the integrated ECAP processing, the massive 18 R phase was broken from 100 μm (as-cast) to 5–8 μm (12 passes), and the precipitated 14H phase was more uniformly distributed in the fined α-Mg matrix. Accordingly, the corrosion resistance of the LPSO-containing samples from 0 to 8 ECAP passes increased for a more uniform and more refined structure. In contrast, the corrosion resistance improvement of the 12-pass ECAP one was reduced slightly for weakened 18 R barriers.

Microstructure Evolution and Properties of β-TCP/Mg-Zn-Ca Biocomposite Processed by Hot Extrusion Combined with Multi-Pass ECAP

To further improve the comprehensive performance of Mg-based alloy, hot extrusion combined with multi-pass equal channel angular pressing (ECAP) was applied to process Mg-3 wt%Zn-0.2 wt%Ca alloy and 1 wt%β-TCP/Mg-3 wt%Zn-0.2 wt%Ca biocomposites. The microstructure evolution, mechanical properties, corrosion behavior, and cell biocompatibility of the experimental specimens were systematically investigated. The average grain size of 13.4 ± 0.6 μm in MgZnCa alloy and 9.6 ± 0.3 μm in composites materials can be achieved by six ECAP passes. The uniaxial compressive strength (UCS) of 388.4 ± 7.3 MPa and the strain at failure of 14.3 ± 1.5% were confirmed in MgZnCa alloy, while the UCS of 405.3 ± 7.4 MPa and the strain at failure of 9.8 ± 1.9% were achieved by the addition of β-TCP after six ECAP passes. In spite of different compositions, the minimum corrosion rate of 0.895 mm·Y−1 and 1.117 mm·Y−1 can be achieved by two ECAP passes at 593 K. The cytocompatibility evaluation revealed that the experimental materials processed by six ECAP passes had no significant cytotoxicity to L929 cells, and the addition of β-TCP improved the cytocompatibility.

Effect of high-temperature ECAP on grain coarsening and refinement

Multi-pass equal-channel angular pressing (ECAP) experiments were carried out on extreme-cooled 7055 aluminium alloy at 400°C. The microstructure of 7055 aluminium alloy was characterised by X-ray diffraction (XRD), electron backscatter diffraction (EBSD), and transmission electron microscopy (TEM). The results reveal two distinct grain sizes: some coarsened grains exist in the microstructure, and most fine grains are distributed near and inside the coarse grains. The deformation texture is weakened, the recrystallisation texture is enhanced, and the recrystallisation texture {124} 〈211〉 (R) is more sensitive to strain. The refined grains are mainly mechanically refined by large shear deformation, the coarsened grains be formed by sub-grain merging and growth at high temperatures.

Optimizing microstructure and mechanical properties of biomedical Mg–Y–Zn–Mn alloy with LPSO phases by solution treatment plus equal-channel angular pressing

Long-period stacked ordered (LPSO) Mg–Y–Zn alloys have shown great medical prospects. To explore the impact of LPSO phase evolution on mechanical properties, a new biomedical Mg-2.2Y-1.1Zn-0.4Mn (wt.%) alloy prepared by solution treatment plus equal-channel angular pressing (ECAP) was systematically investigated. The results indicate that massive 18R LPSO networks along α-Mg grain boundaries are disintegrated during solution treatment of the as-cast alloy, whereas 14H lamellas are precipitated in α-Mg grains. Following a similar dispersion of 14H precipitated phases, the remnant 18R network phase was gradually extended, broken, and refined throughout the subsequent multi-pass ECAP process. The refined LPSO phases promote dynamic recrystallization (DRX) during the severe deformation process and improve mechanical properties of the obtained fine-grained alloy. After 773K solution treatment for 10h plus 693K ECAP for 12 passes, the biomedical alloy with co-existing 18R and 14H LSPO phases shows excellent mechanical properties with an ultimate tensile strength of 326.6 MPa and elongation of 14.5 percent.

Achieving ultra-fine grains and high strength of Mg–9Li alloy via room-temperature ECAP and post rolling

Ultra-fine grains (UFG’s) and high strength was successfully achieved in Mg–9Li alloy via room temperature (RT) equal channel angular pressing (ECAP) and post rolling. The solid solution (SS) treatment of the alloy was performed before ECAP to achieve the refined needle-like α-Mg phase and excellent RT plastic deformation ability. The SS-treated alloy was ECAP processed continuously for 8 passes at room temperature without any cracks. Low temperature effectively inhibits dynamic recovery and recrystallization during the multi-pass ECAP process, reaching ultra-fine grains of about 1 μm and ultimate tensile strength (UTS) values of 187 MPa of the alloy. Post RT rolling of the ECAP-processed alloy further refines the grains into ultra-fine grains ranging between 500 and 700 nm, which endows the alloy with an excellent UTS value of 206 MPa and decent elongation to failure (Ef) of 21%. The ultra-fine grains with certain intragranular dislocation, leading to grain boundary and dislocation strengthening was a major contributory factor to the obtained high strength. Texture strengthening from the formation of strong basal textures of the α-Mg phase also improved the strength.

Tailoring of microstructure and shape memory properties of hot-forged NiTiNb alloy by multi-pass ECAP at high temperatures

NiTiNb is a wide-hysteresis shape memory alloy, and the microstructure directly affects the shape memory properties. In this study, the microstructures and shape memory properties of hot-forged NiTiNb alloys were tailored by multi-pass equal-channel angular pressing (ECAP) at high temperatures. First, grain refinement structures with severely deformed grains and fully dynamic recrystallized equiaxed grains were prepared by ECAP at 650 °C and 800 °C (denoted as ECAP-650 and ECAP-800, respectively). The correlation between the two types of ECAP-based microstructures and shape memory properties of the NiTiNb alloy was established. The results indicated that there was no direct relationship between the grain size and thermally induced martensite (TIM) transformation. However, the dislocations in the deformed grains hindered the TIM transformation, resulting in a lower martensite transformation temperature. The greater β-Nb deformation during the stress-induced martensite (SIM) increased the martensite transformation hysteresis of the ECAP-processed samples. Simultaneously, the recrystallized grains were more beneficial to the stability of the SIM. Compared with the initial sample, the transformation hysteresis temperatures of the ECAP-650 and ECAP-800 samples increased by 29 °C and 34 °C, respectively. The refined grains were not conducive to the recovery of transformation strain, but they were beneficial for increasing the recovery stress. Compared to the initial sample, the recoverable transformation strain of the ECAP-650 and ECAP-800 samples decreased by 18.3% and 6.6%, respectively, and the corresponding maximum recovery stresses increased by 23.7% and 12.2%. Similar to the recovery stress, the thermomechanical cyclic stability of the ECAP-processed samples was also improved because the dislocation content introduced by lattice mismatch was reduced, and the sample with deformed grains had better stability than the sample with recrystallized grains.

Improvement of ductility and work hardening ability in a high strength Zn-Mg-Y alloy via micron-sized and submicron-sized YZn12 particles

In this study, the effects of Y addition on microstructure and mechanical properties of Zn-Mg alloy during multi-pass equal channel angular pressing (ECAP) were systematically investigated. The results show that apart from α-Zn matrix and network-shaped eutectic Zn+Mg2Zn11 structure, micron-sized and submicron-sized YZn12 particles were formed in as-cast alloy. During multi-pass ECAP, the α-Zn matrix was refined via dynamic recrystallization (DRX), and the eutectic structure was fragmented into fine particles gradually, while the YZn12 particles became further refined (~100 nm) only from 8p to 12p ECAP. Tensile tests at room temperature indicated that the 12p-ECAP alloy exhibits the optimal mechanical properties with ultimate tensile strength of 465 MPa and fracture elongation of 11%. The fine and uniform microstructure contributes to the enhancement of ductility. Furthermore, the improved work hardening ability of 12p alloy was mainly ascribed from the generation of submicron-sized YZn12 particles with the size of ~100 nm, which could induce twinning with them and increase the density of geometrically necessary dislocations. The results suggest that the introduction of second phase particles with twinning ability may be effective to improve the work hardening ability of Zn alloys.

Tailoring Extra-Strength of a TWIP Steel by Combination of Multi-Pass Equal-Channel Angular Pressing and Warm Rolling

Increasing the yield stress of twinning-induced plasticity (TWIP) steels is a demanding task for modern materials science. This aim can be achieved by microstructure refinement induced by heavy straining. We feature the microstructural evolution and mechanical performance of a high-manganese TWIP steel subjected to deformation treatment by different combinations of equal channel angular pressing (ECAP) and rolling at different temperatures. The effect of microstructure on the tensile properties of the steel subjected to the multi-pass ECAP process and to subsequent rolling is reported as well. We show that the combined deformation procedure allows us to further increase the strength of the processed workpieces due to a gradual transition from a banded structure to a heterogeneous hierarchical microstructure consisting of fragments, dislocation configurations and nano- and micro-twins colonies. Rolling of multi-pass ECAP specimens at 375 °C allowed us to achieve an extraordinary strength, the highest among all the investigated cases, while the best trade-off between yield strength and elongation to failure was reached using multi-pass ECAP followed by rolling at 500 °C. This study shows a great potential of using combined deformation techniques to enhance the mechanical performance of TWIP steels.