Equal Channel Angular Pressing Passes Research Articles

Effect of short-time high-temperature stabilization on the microstructure and tensile property of severely deformed Al-Mg-Sc alloy

In this paper, the effect of short-time high-temperature stabilization on the microstructure and tensile property of the Al-Mg-Sc alloy deformed by equal channel angular pressing (ECAP) has been investigated. The results show that the 2-pass ECAP cannot completely refine the grain, and the distribution of the deformed structure is inhomogeneous. After short-time stabilization, the grain of the material is refined, the shear zone becomes small grains with a size of about 1 μm, and the non-uniform deformation structure is alleviated. This change results in a small reduction in strength but a large increase in toughness. Short-time stabilization also improves the workability of the material. Re-deforming the material by another 2 pass ECAP, the sample with short-time stabilization demonstrates fewer internal defects, a more uniform structure, and finer grains.

Investigating the combined influence of rolling, ECAP processes, and intermediate annealing on mechanical and microstructural properties of beryllium copper alloy 25

A beryllium copper alloy 25 underwent a series of processing steps involving rolling, equal-channel angular pressing (ECAP), and subsequent annealing. This study delved into the combined effects of these processes on the microstructural evolution and mechanical properties of the deformed beryllium copper alloy 25. The investigation utilized optical microscopy, scanning electron microscopy, transmission electron microscopy, room temperature Vickers hardness testing, and tensile testing. The findings reveal a notable enhancement in the strength of the beryllium copper alloy 25 while preserving its ductility after subjecting it to six ECAP passes followed by annealing at 210 °C for 20 min, applied to the rolled sample. Initially, an increase in number of ECAP passes resulted in a gradual reduction in grain size and a weakening of the alloy's texture. This led to an increase in ultimate tensile strength up to 333.5% without reducing in percentage elongation. Notably, after six ECAP passes, the average grain size decreased from 48 µm to less than 1 µm, yielding exceptional comprehensive mechanical properties with significantly improved strength and plasticity. The resultant material exhibits promising potential for fabrication into bars and plates for a wide range of applications in aerospace and marine industries.

Evaluation of microstructure and mechanical properties of Al1050/Al2O3/Gr composite processed by forming operation ECAP

Abstract Enhancement of microstructure and mechanical features of the hybrid aluminum matrix composite (HAMC) prepared by the stir-casting process (SCP) is quite significant for failure prevention during the service. In this work, the circular rod of hybrid aluminum matrix composite reinforced with particles of alumina (Al2O3) 50 μm, and graphite (Gr) 40–100 µm fabricated by SCP was adopted. This Al1050/Al2O3/Gr composite was subjected to severe plastic deformation using equal channel angular pressing (ECAP) at room temperature to show the impact of this process on the microstructure and mechanical features of the fabricated composite. Grain refinement, strength, and hardness were evaluated at different forming passes (1P, 3P, and 5P) with two channel angles (die angles) of 120° and 135°. The results revealed that the number of ECAP cycles has a significant effect on the refinement of the grain size. The fifth pass of ECAP (5P ECAP) with a die angle of 120° gave more refinement of the grains in the range of 36–75 nm compared to other passes. On the other hand, the strength and hardness relatively augment until 5P ECAP with increasing the cycle number at two die angles of 120° and 135°. The ultrafine grain can reduce the voids of the aluminum matrix then the hardness is enhanced.

Mechanism of Grain Refinement in 3D-Printed AlSi10Mg Alloy Subjected to Severe Plastic Deformation.

In this article, the evolution of microstructural characteristics of selectively laser-melted AlSi10Mg alloy subjected to equal channel angular pressing (ECAP) is investigated. The microstructures were analyzed in detail using scanning electron microscopy (SEM), electron backscatter diffraction (EBSD), transmission Kikuchi diffraction (TKD), and transmission electron microscopy (TEM). A heterogeneous ultrafine-grained microstructure was produced after one ECAP pass at 100 °C. This microstructure was composed of Al/Si cells and sub-micrometer grains. The grains were refined by conventional dislocation processes; however, evidence of dynamic recrystallization was also documented. Furthermore, it was revealed that the Al/Si cells contribute significantly to grain refinement. EBSD/TKD investigations showed that cell misorientation increased after ECAP processing, resulting in an increased fraction of grains with very low misorientation angles.

Enhanced strength and plasticity of 316L austenitic stainless steel through combined ECAP and annealing treatment

The mechanical properties of 316L austenitic stainless steel (ASS) were enhanced by equal channel angular pressing (ECAP) combined with annealing treatment. High-density dislocations, twins, and slip bands are generated during 4 passes ECAP. An appropriate annealing treatment is beneficial for overcoming ductility loss and maintaining strength of ECAP samples. In this study, we found that annealing at 700 °C for 1 h and 600 °C for 12 h can achieve this goal, mainly due to the recovery of stacked dislocations at boundaries and the retention of nanoscale twins and slip bands.

Enhancing mechanical properties and microstructure evolution of hybrid AZ61-5SiC-0.5CNTs composite during equal channel angular pressing

Equal channel angular pressing (ECAP) is one of widely used severe plastic deformation methods for improving performance of metallic materials. In this work, the effects of the ECAP on the microstructural evolution and mechanical properties of the AZ61–5SiC-0.5CNTs composite were studied systematically. The results revealed that ECAP can effectively reduce the porosity of the AZ61–5SiC-0.5CNTs composite, refine grains, weaken basal texture, and promote the further dispersion of CNTs, which can optimize the microstructure of the composite. However, the large shear effect of ECAP also leads to the destruction of the structural integrity of the CNTs and thus reduces the strengthening effect. Due to the combined effects of grain refinement, porosity changes, texture evolution, and structural damage of CNTs, the composites reached the highest strength after 2 ECAP passes at 250 ℃. The yield and tensile strengths were increased to 383 MPa (+11.0 %) and 445 MPa (+8.0 %), respectively, while the elongation was marginally reduced, but remained around 6 %.

In-situ synchrotron diffraction analysis of deformation mechanisms in an AA5083 sheet metal processed by modified equal-channel angular pressing

Severe plastic deformation (SPD) is a process to significantly improve the mechanical properties of materials by grain refinement. For forming at room temperature (RT), higher strengths can thus be achieved; for increased temperatures (HT), greater elongations can be achieved. This great potential has been chiefly applied only on laboratory scale due to a lack of industrial process design. Equal-channel angular pressing (ECAP) offers the possibility to integrate these advantages in industrial processes. This paper investigates a modified ECAP process for aluminum AA5083 sheet metal. Two passes of ECAP for sheet metal and an additional heat treatment were used. To study the material deformation on a micro-scale, in-situ synchrotron measurements at DESY (Hamburg) were performed to analyze the evolution of lattice strains and dislocation densities during tensile testing. The mechanical properties of the ECAP-processed sheet material reveal an increase in yield strength and a decrease in elongation at RT. Higher strains can be measured for the processed material at elevated test temperatures. In-situ diffraction results show a changed behavior of the ECAP sheet material compared to the reference material for both temperature regimes. These changes are based on the increased defect density in the material, which leads to increased strength at RT. At HT, dynamic recrystallization occurs during tensile testing, and the prevailing deformation mechanisms reconfigure. Electron backscatter diffraction (EBSD) and micrographs are used to interpret and supplement the observations. The findings provide the basis for the in-depth understanding of the deformation behavior of the material and help to apply the ECAP process on an industrial scale.

Effect of equal channel angular pressing on magnesium alloys − A review

Magnesium (Mg) alloys own excellent properties that includes better castability, low density and great specific strength. Mg and its alloys are easily available and economical. Necessity of Mg and its alloys for manufacturing and engineering purposes has increased, predominantly in the area of aircraft and automobile applications. The known limitation of magnesium is its poor formability at room temperature, with inadequate slip systems due to hexagonal closed packed construction of magnesium. Formability of magnesium alloys will be enhanced at room temperature by grain structure refinement which improves ductility with grain refined structure. Severe plastic deformation (SPD) procedure induces extreme strain within the sample to produce ultrafine grained structure. Additionally, few shortcomings of magnesium is increased wear mass loss and corrosion rate obstructing the use of Mg and its alloys in several industrial appliances. Wear resistance and corrosion behaviour can be enhanced by SPD thereby increasing the requirement of magnesium alloys for engineering applications. Among SPD, equal channel angular pressing (ECAP) is an efficient approach to develop and vary the mechanical and microstructural properties as per the need. In ECAP approach, the workpiece undergoes shear deformation and large strains are induced in the workpiece with no variation in cross sectional aspect of the workpiece. Microstructure plays a very important role in achieving the required mechanical properties. ECAP process creates ultrafine-grained microstructure with different number of ECAP passes with varying temperatures inducing high strain rate.

Optimization of wear parameters for ECAP-processed ZK30 alloy using response surface and machine learning approaches: a comparative study

The present research applies different statistical analysis and machine learning (ML) approaches to predict and optimize the processing parameters on the wear behavior of ZK30 alloy processed through equal channel angular pressing (ECAP) technique. Firstly, The ECAPed ZK30 billets have been examined at as-annealed (AA), 1-pass, and 4-passes of route Bc (4Bc). Then, the wear output responses in terms of volume loss (VL) and coefficient of friction (COF) have been experimentally investigated by varying load pressure (P) and speed (V) using design of experiments (DOE). In the second step, statistical analysis of variance (ANOVA), 3D response surface plots, and ML have been employed to predict the output responses. Subsequently, genetic algorithm (GA), hybrid DOE–GA, and multi-objective genetic algorithm techniques have been used to optimize the input variables. The experimental results of ECAP process reveal a significant reduction in the average grain size by 92.7% as it processed through 4Bc compared to AA counterpart. Furthermore, 4Bc exhibited a significant improvement in the VL by 99.8% compared to AA counterpart. Both regression and ML prediction models establish a significant correlation between the projected and the actual data, indicating that the experimental and predicted values agreed exceptionally well. The minimal VL at different ECAP passes was obtained at the highest condition of the wear test. Also, the minimal COF for all ECAP passes was obtained at maximum wear load. However, the optimal speed in the wear process decreased with the number of billets passes for minimum COF. The validation of predicted ML models and VL regression under different wear conditions have an accuracy range of 70–99.7%, respectively.

Wear behaviour of aluminium-based hybrid composites processed by equal channel angular pressing

In the present investigation, a systematic experimental wear study at room temperature on Al2618 and reinforced Al2618 in the solutionized state, and after each pass of equal channel angular pressing (ECAP) was taken up to obtain a fundamental understanding of the wear behaviour and generate reference data on wear properties. The authors prepared a hybrid composite using Al2618 with boron carbide (5 wt.%) and graphite (5 wt.%) by the stir casting process. Solution treated cylindrical specimens of Al2618 and reinforced Al2618 were subjected to four passes of ECAP through a 120° die at room temperature using the processing route (BC). From the results point of view, microhardness measurements were carried out at room temperature on the specimens from the solutionized work piece before and after each pass of ECAP. Scanning electron microscope and X-ray diffraction techniques were used to conduct the microstructural studies. After three passes through both routes, the microstructure showed elongated grains with many dislocations; and after four passes, the microstructure depicted nearly equiaxed grains. Sub micrometre sized grains were produced after three passes of ECAP. Moreover, there was a monotonic increase in the hardness values with an increase in the number of passes. Finally, we reported that there was an improvement in the wear resistance of Al2618 and reinforced Al2618 subjected to ECAP process. This scrutiny may accelerate the applications of aluminium alloys in the industrial sector.

Effect of Zinc and Severe Plastic Deformation on Mechanical Properties of AZ61 Magnesium Alloy.

This study investigates the effects of zinc (4 wt.%) and severe plastic deformation on the mechanical properties of AZ61 magnesium alloy through the stir-casting process. Severe plastic deformation (Equal Channel Angular Pressing (ECAP)) has been performed followed by T4 heat treatment. The microstructural examinations revealed that the addition of 4 wt.% Zn enhances the uniform distribution of β-phase, contributing to a more uniformly corroded surface in corrosive environments. Additionally, dynamic recrystallization (DRX) significantly reduces the grain size of as-cast alloys after undergoing ECAP. The attained mechanical properties demonstrate that after a single ECAP pass, AZ61 + 4 wt.% Zn alloy exhibits the highest yield strength (YS), ultimate compression strength (UCS), and hardness. This research highlights the promising potential of AZ61 + 4 wt.% Zn alloy for enhanced mechanical and corrosion-resistant properties, offering valuable insights for applications in diverse engineering fields.

Refractory High‐Entropy Alloys Produced from Elemental Powders by Severe Plastic Deformation

A comparative investigation of two fundamentally different approaches for the synthesis, microstructure evolution, and mechanical properties of the refractory high‐entropy alloys (RHEA) HfNbTaTiZr and HfNbTiZr is performed. The two methods comprises conventional arc (button) melting and a powder route based on mechanical alloying and consolidation via severe plastic deformation. In particular, blended elemental powder is pre‐compacted and subjected to one or four passes of equal channel angular pressing (ECAP) at 500 °C and then 10 revolutions of high pressure torsion (HPT) at room temperature to an effective strain between 4 and 40. Some samples are then annealed at 500 °C for 1 h to investigate the thermal stability of the phases. The four ECAP passes at 500 °C do not result in the formation of the body‐centered cubic (BCC) phase typical for the program RHEAs despite the presence of interfacial zones between particles and defect‐driven diffusion. Nevertheless, a single ECAP pass is sufficient to create a solid bulk sample for subsequent HPT. After 10 HPT revolutions, in contrast to melting route resulting in a single BCC phase alloy, both alloys form new phases comprising a Nb‐rich BCC phase and a ZrHf‐rich HCP phase in both alloys.

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.

Enhanced superplasticity of ultrafine-grained WEQ612 magnesium alloy via the coupling effect of grain boundary segregation and dense precipitation

Achieving low-temperature, high-strain-rate (LTHSR) superplasticity is important for preparing rare-earth (RE)–Mg alloy products with complex shapes. Herein, an ultrafine-grained Mg–6.22Y–0.98Er–2.11Ag (wt%, WEQ612) alloy was prepared via equal-channel angular pressing (ECAP). After 16 passes of ECAP and aging at 473 K for 58 h, an average grain size of 600 nm was achieved, and there was a high density of intergranular precipitates with an average size of approximately 180 nm. The WEQ612 alloy exhibited excellent superplasticity during superplastic deformation, with elongations of 451% at 523 K and 1 × 10−4 s−1, and 834% at 573 K and 1 × 10−2 s−1. The high density of intergranular precipitates, which were uniformly distributed at the grain boundaries, promoted dynamic recrystallization (DRX) during superplastic deformation and inhibited grain growth. The grain boundary co-segregation of Y and Ag further improved the grain boundary stability of the alloy. Despite the general consensus that grain boundary sliding (GBS) is the main mechanism of superplasticity, a more complex role of GBS and DRX was identified in this study. The identified mechanism provides a reference for GBS and grain boundary rotation as well as dislocation motion during superplastic deformation, and helps to describe the intermediate processes that occur during superplastic deformation. Thus, this study provides insights into the development of LTHSR superplastic RE–Mg alloys.

Mechanical properties and microstructure of Al–Mg (5052) alloy processed by equal-channel angular pressing (ECAP) with variation of ECAP routes and heat treatment

Equal-Channel Angular Pressing (ECAP) has become an effective technique of severe plastic deformation designed to produce ultrafine grain metals with improved mechanical properties, such as a good combination of strength and ductility. A report on the effect of ECAP routes on the mechanical and microstructure of commercial 5052 aluminum alloy needs also to be included. This work has been undertaken, in order to obtain the results. In this work, several deformation routes were used to process the Al – Mg (5052) alloy, namely A, Ba, Bc and C. Deformation route A involved repeatedly pushing the sample into the ECAP die without rotation, route Ba was performed by rotating the sample through 90° in alternate directions between each pass, route Bc by rotating the sample 90° in the same sense between each pass and route C by rotating the sample 180° between passes. The addition of the pass number decreases the grain size of ECAP-processed samples when compared to the as-annealed sample. It also confirmed that the microstructure of the 8-pass samples shows a finer grain size than the as-annealed sample. Furthermore, the Bc route (samples rotated in the same sense by 90° between each pass) has been proven to be the most effective deformation route, in order to obtain equiaxed ultrafine grain structure when compared to other deformation routes. This phenomenon takes place due to the continuous deformation in all cubic planes. The restoration after the 4-pass number will lead to the rapid evolution of sub-grains to high-angle grain boundaries, forming equiaxed grains. The characterization of the hardness number also shows that the addition of the ECAP pass number increases the hardness number of 5052 aluminum alloy, where samples processed with the Bc route indicate the highest hardness number at 168.4 HB. Moreover, a similar phenomenon also suggests that the tensile strength of all ECAP deformation routes has comparable values. The effect of heat treatment for samples with the Bc route also shows that 200 °C annealed samples have the highest hardness number and tensile strength when compared to other samples.

Effect of number of ECAP passes on structure and mechanical properties of Al–Ca–Mn–Fe alloy

The effect of number of equal-channel angular pressing (ECAP) passes on the structure and mechanical properties of the as-cast 4% Ca–1.3% Fe–0.8% Mn–0.1% Zr–0.1% Sc Al alloy is studied. ECAP was carried out at room temperature, through BC path using an angle between the channels of 110°. The number of ECAP passes was N = 2, 3, and 4. The as-cast alloy consisted of the solid solution dendrites (Al) and the [(Al) + Al10CaFe2 + Al4Ca] eutectic, as well as of a small fraction of the Al6(Fe, Mn) particles. As a result of ECAP, the dendrites are elongated approximately at an angle of 30° relative to the direction of ECAP. After two passes of ECAP, the dislocation density increased, but with an increase in the number of passes, the dislocation density slightly decreased as a result of the rearrangement of the dislocation structure; besides calcium segregated from the eutectic. After ECAP, a significant hardening of the alloy was observed. The highest strength observed after two passes (the ultimate tensile strength of the as-cast alloy was 130 MPa, and after the second pass it was 305 MPa), and the lowest one was after four passes (the ultimate strength was 219 MPa). The relative elongation of the ECAP-processed samples did not depend on the number of passes and it was about 1%.

Microstructure evolution and mechanical properties of Mg–Mn–RE alloy processed by equal channel angular pressing

Equal Channel Angular Pressing (ECAP) has been used to successfully produce ultrafine-grained ME21 alloy with a good strength-ductility synergy. The microstructure of the as-cast ME21 alloy and its evolution during the ECAP processing were characterized using a combination of optical microscopy (OM) and scanning electron microscopy (SEM). Fracture surfaces after tensile test were also characterized using SEM. Chemical analysis and phase identification were done by energy dispersive spectroscopy (EDS) and X-ray diffraction analysis, respectively. The combination of these techniques enabled the interpretation of the mechanical behavior during the various processing stages of the alloys. The ECAP process was performed up to 16 passes, producing a uniform ultra-fine grain (1 µm) ME21 alloy resulting from full dynamic recrystallization. At room temperature, the yield strength after 16 ECAP passes (191.4 MPa) was 251% higher than that of the as-cast ME21 alloy, accompanied by a good elongation of 8.1%. The hardness increased to 60.7HV which is about 52% higher than that of the as-cast alloy. These improvement in mechanical properties is due to the ultra-fine grains with high angle grain boundaries (HAGBs) and the precipitate strengthening effects of the uniformly dispersed fine precipitates of Mg12Ce and Mn formed as a result of the intense shear during the ECAP process.

Processing of the Ti25Ta25Nb3Sn Experimental Alloy Using ECAP Process for Biomedical Applications

The development of titanium-β alloys for biomedical applications is associated with the addition of alloying elements or the use of processing techniques to obtain suitable bulk properties. The Ti25Ta25Nb3Sn alloy has been highlighted for its mechanical properties and biocompatibility. To further enhance the properties of titanium alloys for biomedical applications, equal channel angular pressing (ECAP) was used due to its capability of refining the microstructure of the alloy, leading to improved mechanical properties without significant changes in Young’s modulus. This study aims to evaluate the impact of ECAP on the microstructure of the Ti-25Sn-25Nb-3Nb alloy and investigate the correlation between the microstructure, mechanical properties, and corrosive behavior. Grain refinement was achieved after four ECAP passes, with an average grain diameter of 395 nm and a non-homogeneous structure, and microhardness was slightly increased from 193 to 212 HV after four ECAP passes. The thermomechanical aspects of the ECAP processing have led to the formation of a metastable α″ phase during the first two passes, while after four passes, the structure was composed only of the β phase. The corrosion resistance of the alloy was increased after four passes, presenting the best results in terms of the improvement of passivation corrosion density.

Refining 18R-LPSO phase into sub-micron range by pre-kinking design and its prominent strengthening effect on Mg97Y2Zn1 alloy

In this study, a composite deformation strategy of pre-kinking (equal channel angular pressing (ECAP)) followed by large-ratio hot extrusion (HE) was designed to refine the 18R long period stacking ordered (LPSO) phase into sub-micron range in a Mg97Y2Zn1 (at.%) alloy. After the composite processing, the mechanical properties of the alloy are significantly enhanced, superior to the majority of reported Mg97Y2Zn1 and other LPSO-containing Mg alloys. Among the composite deformed alloys, the 16P-HE alloy exhibits the best mechanical properties with tensile yield strength (TYS) of 475 MPa, ultimate tensile strength (UTS) of 526 MPa, and fracture elongation (FE) of 14.5%. Quantitative analysis of 18R phase indicates that increasing ECAP pass from 1 to 16 gradually decreases the average size of 18R phase from 5.1 µm to 2.3 µm. After HE, the 18R phase is further refined with a corresponding decrease in the average size in the descending order of 1P-HE (4.3 µm), 4P-HE (3.2 µm), and 16P-HE (1.4 µm) alloys. Calculation of the strengthening contributions confirms that the superior mechanical properties of 16P-HE alloy are mainly due to its strongest interface strengthening (145 MPa) and grain boundary strengthening (189 MPa) from the sub-micron 18R phase and α-Mg grains. Moreover, the strengthening effect of 18R phase decreases gradually with their morphology changing from particles to fibers, and to blocks. The obtained results further deepen and broaden the strengthening-toughening theory of 18R phase.

Effect of intermediate-temperature severe plastic deformation on microstructure evolution, mechanical properties and corrosion behavior of an Al-Zn-Mg-Cu alloy

Grain refinement is an important means to strengthen the properties of alloy. Here the Al-Zn-Mg-Cu alloy was processed by intermediate-temperature equal channel angular pressing (ECAP) to evaluate the grain refinement, mechanical properties and corrosion resistance of the alloy. Ultra-fine grained structure was obtained by 4 passes ECAP applied to Al-Zn-Mg-Cu alloy. With the increase of ECAP passes, some low angle grain boundaries (LAGBs) transform to high angle grain boundaries (HAGBs), forming micron-sized fine grains. Meanwhile, the strength, microhardness and corrosion resistance of the alloy were improved with the increase of extrusion passes. The pinning effect caused by dynamic precipitation and the mechanical fragmentation caused by ECAP refine the grains of the alloy. The microhardness and strength of the deformed alloy were improved under the combined action of fine grain strengthening, dislocation strengthening and second phase strengthening. A high density of dislocations, refined grains and secondary phases were produced by intermediate-temperature ECAP, which together improved the corrosion resistance of the alloy.