Accumulative Roll Bonding Process Research Articles

Nanostructured Composite Foils Produced Via Accumulative Roll Bonding as Lithium-Ion Battery Anodes.

In this work, we introduce a new nanostructured composite foil (NCF) alloying anode framework for high-capacity anode materials for lithium-ion batteries. These materials are manufactured with an accumulative roll-bonding process, a simple route for the generation of hierarchical nanostructures. The model Sn/Cu NCF system provides volumetric capacities between 1000 and 1720 mA h cm-3, equating to a projected 20-50% increase in cell-level volumetric energy density. The initial electrochemical cycle was associated with an efficient formation process (88-92%) that drastically increased transport kinetics, allowing for rapid lithiation (>8 mA cm-2) on subsequent cycles. The introduction of a multilayered inactive copper matrix successfully eliminated loss of the active material as a degradation mechanism, while loss of lithium-inventory limited long-term cyclability in lithium-limited environments. Further development of this framework to mitigate loss of lithium inventory may provide a promising route toward the production of high-energy battery materials.

The Bonding Interface and Tribological Properties of Cu–Graphite Sandwich Composites Fabricated via Accumulative Roll-Bonding Processes

Copper–graphite sandwich composites are new functional composites with excellent tribological and mechanical properties. More and more researchers prepare the sandwich composites by accumulative roll-bonding processes due to severe plasticity deformation. The microstructure and properties of copper–graphite sandwich composites prepared by continual annealing and accumulative roll-bonding processes for eight rolling cycles were investigated. The results showed that with the increase of rolling cycles, the dispersion of graphite particles between two copper layers along a rolling direction became more uniform, the pores at the interface between graphite particles and the Cu matrix gradually disappeared, and the hardness of copper–graphite composites gradually increased. After eight rolling cycles, the Vickers hardness of the composites increased by 140.8% as compared with that of annealed pure copper. During friction, the steel balls can meet some graphite particles in the composites rolled by four cycles. The friction coefficient and wear loss of copper–graphite composites gradually decreased with the increase of rolling cycles. Compared with the composites rolled by one cycle, the friction coefficient and wear loss of the composites rolled by eight cycles were reduced by 32.5 and 49.0%, respectively. The main wear mechanism gradually evolved from fatigue wear and abrasive wear to adhesive wear, and then to fatigue wear.

Microstructure and properties analysis of accumulative-roll-bonding-processed Mg–Li/Ta composites for shielding of high-energy electron

The rational combinations of low/high-density metallic materials have been proved to be effective in shielding high-energy electron radiation, however, little has been studied and reported about their synthesis, microstructure, properties and stability against irradiation. In present work, Mg–Li alloy and pure Ta sheets were used to prepare such a novel low/high-density shielding composite by accumulative roll bonding (ARB). Results showed that a uniformed microstructure of composite could be produced after four ARB cycles. Both ARB process and irradiation caused no obvious change in phase compositions of raw materials. In larger areal mass 8.2–12.3 g/cm2, the Mg–Li/Ta composite is a more efficient shield than pure Mg–Li and Ta. Treated by irradiation, a notable number of cavities accompanied by dislocations were formed as main defects in α-Mg phase. The induced dislocations facilitated the nucleation and growth of {1 0–1 2} twins, which in turn acted as sinks of defects. By contrast, Ta phase exhibited good radiation stability as no signs of visible cavities. During ARB process and irradiation, the textures of α-Mg and Ta in composite all varied distinctly. The average micro-hardness of Mg–Li and Ta phase increased with ARB cycles. Treated by irradiation, Mg–Li matrix was sharply hardened while hardness of Ta was slightly decreased. The tensile strength of Mg–Li/Ta composite increased in ARB process and reached the maximum after four cycles. After irradiation, composite exhibited same strength but severe loss of ductility.

A review on recent advances in accumulative roll bonding of similar, dissimilar and metal matrix composites

Extracting of lightweight metallic materials with ultra-fine grain arrangement passed through severe plastic deformation (SPD) having high strength had a large stretch of applications in automobiles, aerospace, and bio-medical sectors. SPD is a metal forming method in which the material is subjected to a considerable amount of plastic strain, resulting in an ultra-fine grain structure having less than 50 nm. In several (SPD) processes, the accumulative roll bonding (ARB) process is mostly preferred in industries that can be widely used to produce bulky materials continuously. This present keynote review paper discusses the modern improvements in the ARB process, basics and mechanisms of bonding of materials, mechanical properties such as strength, ductility, toughness and it also discuss the microscopic structure of the material, and it draws a contrast between the materials that underwent ARB process compared with normal metal sheets. Moreover, ARB processed materials have the potential for high performance.

Microstructure and mechanical behaviors of Al/Cu laminated composites fabricated by accumulative roll bonding and intermediate annealing

Strength and toughness of laminated composites with alternatively stacked “brick-and-mortar” structure can be synchronously improved along the direction parallel to the layer interface. However, it is still a challenge to prepare high-performance laminated composites in large quantities to meet industrial needs. In this work, we employ accumulative roll bonding (ARB) and/or intermediate annealing to prepare Al/Cu laminated composites as cheaper substitutes for Cu alloys due to lightweight and considered electrical conductivity. Our results show that the ARB process decreases the layer thicknesses and grain sizes, and improves the Vickers micro-hardness of Al/Cu laminated composites. As the ARB cycle increases from 1 to 8, the tensile strength firstly increases from 279.20 MPa to 358.71 MPa, and then decreases to 317.88 MPa. Meanwhile, the uniform elongation firstly increases from 1.25% to 1.71%, and then decreases to 0.58%. These variations of tensile properties are tightly linked to the layer-integrity and microstructures of Al and Cu layers. Moreover, the intermediate annealing (350 °C for 30 min) applied after every 2 ARB cycles can significantly increase the tensile strength, uniform elongation and elongation to failure, especially for Al/Cu laminated composites with high ARB cycles, because intermediate annealing remarkably improves the interfacial metallurgical bonding and continuity/integrity of Al and Cu layers. However, the final annealing for long time would introduce brittle intermetallics (like AlCu and Al2Cu), and therefore deteriorate the tensile ductility. This work provides a new treatment process for fabricating Al/Cu laminated composites with synchronously increasing strength and ductility.

Textured Electrodes: Manipulating Built-In Crystallographic Heterogeneity of Metal Electrodes via Severe Plastic Deformation.

Control of crystallography of metal electrodeposit films has recently emerged as a key to achieving long operating lifetimes in next-generation batteries. It is reported that the large crystallographic heterogeneity, e.g., broad orientational distribution, that appears characteristic of commercial metal foils, results in rough morphology upon plating/stripping. On this basis, an accumulative roll bonding (ARB) methodology-a severe plastic deformation process-is developed. Zn metal is used as a first example to interrogate the concept. It is demonstrated that the ARB process is highly effective in achieving uniform crystallographic control on macroscopic materials. After the ARB process, the Zn grains exhibit a strong (002) texture (i.e., [002]Zn //ND). The texture transitions from a classical bipolar pattern to a nonclassical unipolar pattern under large nominal strain eliminate the orientational heterogeneity of the foil. The strongly (002)-textured Zn remarkably improves the plating/stripping performance by nearly two orders of magnitude under practical conditions. The performance improvements are readily scaled to achieve pouch-type full batteries that deliver exceptional reversibility. The ARB process can, in principle, be applied to any metal chemistry to achieve similar crystallographic uniformity, provided the appropriate temperature and accumulated strains are employed. This concept is evaluated using commercial Li and Na foils, which, unlike Zn (HCP), are BCC crystals. The simple process for creating strong textures in both hexagonal and cubic metals and illustrating the critical role such built-in crystallography plays underscores opportunities for developing highly reversible thin metal anodes (e.g., hexagonal Zn, Mg, and cubic Li, Na, Ca, Al).

Microstructural evolutions and mechanical properties of multilayered 1060Al/Al–Al2O3 composites fabricated by cold spraying and accumulative roll bonding

A multiple processing technique that combines cold spraying (CS) and accumulative roll bonding (ARB) was designed to prepare multilayered 1060Al/Al–Al2O3 composites with improved ductility. Microstructural evolution during processing was characterized using scanning electron microscopy (SEM) and electron backscattered diffraction (EBSD). The deposited Al–Al2O3 complex layer was well bonded to the 1060Al matrix, and during ARB processing, the deposited layers were highly squeezed to eliminate voids, Al2O3 particles were split to reduced size and dispersed to a homogeneous distribution within the deposited layers. The tensile test results revealed that the best combination of strength and ductility was achieved in the sample with optimized 3-pass ARB processing, with an increase of ∼41.66% in ultimate tensile strength (153 MPa) and an increase of ∼95.73% in tensile elongation (7.34%) compared to the initial As-Annealed sample. Fracture behavior of the prepared composite was also analyzed. The analysis of microstructural features provided insight into the underlying mechanisms explaining the high strength and great ductility.

Study of mechanical properties and wear resistance of Al 1050/Brass (70/30)/Al 1050 composite sheets fabricated by the accumulative roll bonding process

The wear phenomenon is one of the essential factors in the failure of industrial components. Therefore, it is vital to investigate the wear behavior of engineering materials and metal matrix composites (MMC). In this article, Al 1050/Brass (70/30)/Al 1050 composite sheets were fabricated using the accumulative roll bonding (ARB) process. The ARB process was performed at ambient temperature without any heat treatment between the cycles in 5 passes. Mechanical properties, fracture surface, and wear behavior of the specimens were also measured. The tensile strength of the Al/Brass/Al sandwich sample is higher than the primary aluminum and less than the original brass. As the number of ARB cycles increases, the tensile strength and elongation changes have no significant trend. The highest ultimate tensile strength was obtained in the first cycle at 288 MPa, which is about 3.5 times the primary aluminum. The highest hardness was also obtained for aluminum and brass after the end of the fourth cycle. Pin-on-disk wear tests were applied with two different forces on specimens, and as an important achievement, the results show that by using Al/Brass/Al composite can increase the wear resistance of aluminum. Worn surface morphology and wear debris of samples were also examined by scanning electron microscopy (SEM). The optical microscope's checking of the layers shows that the brass layer is completely crushed in the aluminum field from the second cycle onwards. Fracture surface images of the samples also show both ductile and brittle fractures.

On the microstructure, texture and mechanical properties through heat treatment in Al–CuO nanocomposite fabricated by Accumulative Roll Bonding (ARB)

This study focuses on the Al-0.5 vol% CuO composite creation. Therefore, the researchers used the accumulative roll bonding (ARB) process to establish the Al-0.5 vol% CuO composites. The composites were created in three ARB methods; the usual way, with rapid annealing and preheating between ARB cycles. Heat treatment was adjusted at 190 ᵒC and lasted for 5 min. This study used a small amount of reinforcing particles, which resulted in the absence of any porosity in the composite. The ARB process resulted in the average size of the created composite grain in the usual way, with the rapid annealing and preheating to be 219.19 nm, 306.54 nm, and 355.65 nm, respectively. The composite creation through the ARB process increased the tensile strength by more than 2.5 times. The ARB with preheating, causes dynamic recovery, dramatically reducing the metal matrix hardness. In this way, the particles were swept instead of getting spread. Therefore, the tensile strength and elongation of the sample were lowered.

Structural and corrosion behavior investigation of novel nano-quasicrystalline Al-Cr-Fe reinforced Al-matrix composites produced by ARB process

In the present study, aluminum metal matrix composites (AMCs) reinforced with Al-Cr-Fe quasicrystal (AlQC) nanoparticles (3 and 5 wt%) and monolithic Al were produced by the accumulative roll bonding (ARB) process up to 8 cycles. X-ray diffraction (XRD) and scanning electron microscopy were employed for structural evaluation. XRD results confirmed the presence of AlQC nano-powders in the Al matrix and the decrease of the matrix crystallite size to a nanometric scale (105 nm) after eight cycles. Microstructural studies showed an improvement in the distribution of the AlQC nanoparticles in the matrix, as well as the connection improvement between Al layers by increasing ARB cycles. Density measurements also showed that theoretical density of the composite samples was greater than the measured density, which is attributed to the presence of voids and pores. Also, corrosion behavior investigations in 3.5 wt% NaCl solution showed that corrosion potential decreases and corrosion rate increases in the presence of AlQC nanoparticles as the reinforcement in comparison to monolithic Al. Finally, a decrease in the corrosion rate of the samples was realized by increasing ARB cycles to the 4 cycle and then an increase was detected by further increasing cycles up to 8 cycles.

Effects of strain accumulation and annealing on interfacial microstructure and grain structure (Mg and Al3Mg2 layers) of Al/Cu/Mg multilayered composite fabricated by ARB process

In this research, Al/Cu/Mg multilayered composites were produced by the accumulative roll bonding (ARB) process and then annealed at different temperatures and times. Microstructural studies showed that with increasing temperature and annealing time in the zero cycle samples, the thickness of the intermetallic compounds (Al 3 Mg 2 and Al 12 Mg 17 ) increased. Also, optical microscopy (OM) images displayed that the Al 3 Mg 2 growth rate was higher than Al 12 Mg 17 . The effect of accumulative strain in various annealing conditions on the thickness of the intermetallic compounds is very low. Its effect is more accelerated to the nucleation of the compounds. Plus, the growth mechanism of the intermetallic layer of Al/Mg was determined to be controlled by diffusion and reaction. The activation energy of Al 3 Mg 2 and Al 12 Mg 17 were calculated to be 73 and 143 Kj.mol −1 , respectively. Evaluation of the grain structure of magnesium layers showed that the grains were equiaxed and strain-free for magnesium at zero cycle and different heat treatment conditions. Besides, shear bands formed by the shear strain concentration enhanced the nucleation of magnesium grains around them in the annealing process and diminished the size of magnesium grains compared to the farther regions. Furthermore, the layer of Al 3 Mg 2 intermetallic compound with equiaxed column structure formed after annealing at different temperatures and times as well as various cycles of ARB.

A texture study of nanostructured Al–Cu multi-layered composite manufactured via the accumulative roll bonding (ARB)

In this study, texture development during the accumulative roll bonding (ARB) of Al–Cu multilayered composite was investigated using X-ray diffraction. Microstructural investigations were also conducted using optical and transmission electron microscopy. The results of textural investigation of the rolled specimens indicated that a strong β-fiber was developed and dominated mainly by the Brass and Copper components in both the Al and Cu layers during the early stages of the ARB process. Moreover, the intensity of the most textural components in both of the metallic layers decreased in the last two ARB cycles. No component other than a weak Rotated Cube was found in the Al layer after the last ARB cycle. In the Cu layer, on the other hand, a Cube component, known as the "recrystallization texture ", was developed which was accompanied by a "rolling texture" represented by the β fiber. Furthermore, the increased misorientation between the grains at high ARB cycles confirmed the formation of high angle grain boundaries in both of the metallic layers. Microstructural investigations showed that the average grain size of the final specimens (after 7 ARB cycles) was less than 500 nm in both Al and Cu layers.

Large-scale synthesis of metal nanosheets as highly active catalysts: Combining accumulative roll-bonding and etching process

Large-scale synthesis of metal nanosheets as highly active catalysts: Combining accumulative roll-bonding and etching process

Microstructure and Mechanical Properties of Al-Mg-Si Similar Alloy Laminates Produced by Accumulative Roll Bonding.

As the applications of heterogeneous materials expand, aluminum laminates of similar materials have attracted much attention due to their greater bonding strength and easier recycling. In this work, an alloy design strategy was developed based on accumulative roll bonding (ARB) to produce laminates from similar materials. Twin roll casting (TRC) sheets of the same composition but different cooling rates were used as the starting materials, and they were roll bonded up to three cycles at varying temperatures. EBSD showed that the two TRC sheets deformed in distinct ways during ARB processes at 300 °C. Major recrystallizations were significant after the first cycle on the thin sheet and after the third cycle on the thick sheet. The sheets were subject to subsequent aging for better mechanical properties. TEM observations showed that the size and distribution of nano-precipitations were different between the two sheet sides. These nano-precipitations were found to significantly promote precipitation strengthening, and such a promotive effect was referred to as hetero-deformation induced (HDI) strengthening. Our work provides a new promising method to prepare laminated heterogeneous materials with similar alloy TRC sheets.

Textural Evolution of 6061 Aluminum Alloy Processed by Accumulative Roll-Bonding Process

A commercial Al-Mg-Si alloy (AA 6061) was deformed by using the accumulative roll bonding (ARB) process for up to five cycles at ambient temperature. The evolution of texture in this process was studied by the X-ray diffraction (XRD) method. Experimental results indicate that the combination of the shear texture composed of Rotated cube {001} component and the rolling textures that included Copper {112} and Dillamore {4, 4, 11} components developed after the first cycle. During the first cycle, the shear texture was developed as a result of shear deformation induced by high level of friction between the rolls and the sheet. By increasing the number of cycles, the shear texture strength diminished and changed to the rolling texture. After the fifth cycle, a remarkable increase in the rolling texture intensity was observed due to homogenous deformation induced by the presence of fine non-shearable particles. Additionally, the presence of magnesium in solid solution influenced the texture evolution during ARB.

DIC-based experimental study of fracture toughness through R-curve tests in a multi-layered Al-Mg (LZ91) composite fabricated by ARB

Adding Li to Mg, dual-phase Mg-Li with very low density and high formability at room temperature was produced and used as a reinforcement phase for fabricating a three-layered metal matrix Al-Mg composite through accumulative roll bonding (ARB) process. In this study, due to the inherent nature of the ARB process, which is associated with high strain, and low strength of the magnesium-lithium alloy, the fracture toughness test and energy absorption were used in addition to the tensile test to observe the interaction effect of the increasing strength and the reducing elongation, which were caused by the ARB. By preparing the compact tension (CT) specimens and conducting R-curve tests, the fracture behavior of the processed composite in various ARB cycles (primary sandwich and four ARB cycles) was investigated. Meanwhile, a Digital Image Correlation (DIC) system was also employed to measure the variation of crack growth, crack opening, and corresponding forces and increase the accuracy and quality of the results. The surrounded area under the force-displacement of crack opening curves was measured and calculated as the toughness and absorbed energy. Tensile strength and total elongation of the processed composite improved gradually, 275.7% and 38%, respectively, compared to the primary phase as the number of cycles increased and the thickness of the layers decreased. Plastic instability was more prominent in the last cycles because of the increasing trend of imposed strains and the reduction in thickness which reached their highest amounts at the final step. Although obtained results confirmed the general improvement in fracture toughness of the ARBed composite, its value varied slightly from one cycle to another. The highest values were achieved for total energy absorption and crack opening at maximum force after the second ARB cycle. In contrast, the maximum amount of fracture toughness, 29.08 MPa m1/2, was belonged to the last cycle of the process. Dimples and micro-cavities, seen in both SEM images of Al and Mg layers, resulted in a ductile failure.

Enhanced Mechanical Properties and Microstructure of Accumulative Roll-Bonded Co/Pb Nanocomposite.

Lead composites have been used as anodes in the electrowinning process to produce metals such as copper and zinc. Manufacturing stable lead anodes with appropriate mechanical and chemical properties is required to improve the performance of the electrowinning process. In this study, an accumulative roll bonding (ARB) method was used to fabricate a Co/Pb nanocomposite. Utilizing the ARB method can help us to achieve a uniform structure with enhanced mechanical properties via severe plastic deformation. The results showed that suitable tensile properties were obtained in Pb–0.5%Co–10pass samples. The tensile strength and strain of these samples were 2.51 times higher and 83.7% lower than that of as-cast pure Pb. They also showed creep resistance and hardness up to 1.8 and 2.5 times more than that of as-cast pure Pb. The ARB technique uniformly distributed Co particles in the Pb matrix. The enhanced strength of Pb samples was observed in the composite including grain sizes of less than 50 nm as a result of hindering the recovery phenomenon. The particle size of the Co distributed in the Pb matrix was 353 ± 259 nm. Compared to conventional methods, the ARB process improved the mechanical properties of Co/Pb composites and can open a new horizon to fabricating this composite in metal industries.

Robot-assisted surface treatment strategies of AA6014 sheet metal for accumulative roll bonding

The application of high strength aluminum sheet metal components in automotive and aviation products effectively saves material and thus weight. Material strengthening can be realized by accumulative roll bonding (ARB), which belongs to the severe plastic deformation processes. Through repeated rolling steps a multilayered sheet metal is produced, which possesses increased strength due to its ultra-fine grained microstructure. Prior to each rolling step a surface treatment via wire brushing is mandatory for removing the oxide layer and roughening the sheet surface, which enables the bonding between the unique layers during rolling. The necessary surface treatment of the sheets is not fully understood by the current state of the art. In the past, it was not possible to achieve a defined and stable surface finish, because the brushing operation was done manually. The improvement of the process stability is essential to determine the relationship between the input parameters for brushing and the resulting bond strength of multilayered ARB sheets. For this reason, a robot-controlled surface treatment is introduced. The investigated material is the precipitation-hardened aluminum AA6014 with a sheet thickness of 1 mm. A suitable brushing kinematic under constant load is implemented and its effects on the surface properties are investigated by roughness measurements. The investigation shows, that the parameter combination leads to comparable or even higher roughness values than through manual brushing. Through 16 consecutive brushing paths a homogeneous and sufficient high surface roughness is realized, which enables material bonding in the rolling step. Thus, the research results indicate, that the robot-assisted surface treatment of ARB sheet metal is a promising method for a better automation and reproducibility of the brushing and the overall ARB process.

Bonding of similar AA3105 aluminum alloy by Accumulative Roll Bonding process

Accumulative roll-bonding (ARB) is a novel plastic straining process aimed at bonding of similar and dissimilar metal combinations. Moreover, it is used recently to produce ultrafine grain materials and metal matrix reinforced composites to enhance mechanical, electrical, and corrosion resistance properties. This work presents an experimental study of roll bonding and accumulative roll bonding of similar AA3105 aluminum alloy at 300°C with a final thickness of 1.2 mm, focusing especially on bond strength evaluation and layers continuities. Tensile tests and three-points bending were performed to mechanical characterize the produced sheets in the various steps and based on the number of the cycles. The maximum strength was reached after 3 ARB cycles. After 4 cycles, the bonding interfaces have a uniform distribution through the sheet thickness, it is possible to distinguish only the interface formed in the last pass in the fracture surface, and no significant enhancement in strength was observed. Starting from 2 ARB cycles, micro-cracks were observed at the outer surface for bending angles greater than 90 deg, and at 180 deg all ARBed samples except A1 were failed.

Investigation of annealing treatment on the interfacial and mechanical properties of Al5052/Cu multilayered composites subjected to ARB process

This research aims to discuss the effect of annealing time and temperature on the interfacial and mechanical properties in Al5052/Cu multilayer composites processed by accumulative roll bonding (ARB). According to the results of XRD and EDS, four intermetallic layers with the chemical composition of Cu9Al4-Cu4Al3-CuAl-Al2Cu were observed at the interface of processed composite with three ARB passes after annealing at 400 °C for 90 min. The results of tensile properties in each specific ARB pass showed that at lower annealing temperatures and times, the recrystallization or recovery was dominant in mechanical properties, and the strength decreased, while at higher annealing temperature and time strength increased due to the thickening of intermetallic compounds. The maximum value of tensile strength (345 MPa) was obtained in the third pass at 400 °C for 90 min. Results of OM analysis on fracture surface by optic microscope of the composites annealed at 350 °C for 60 min demonstrated that from zero to the second pass the fracture path in the macroscopic state was perpendicular to the direction of stress. However, in the third and fourth passes, the macroscopic path of fracture is observed with an angle of 35–45° to the direction of tension, which is due to the formation of shear deformation zones. Also, SEM analysis of the third pass sample annealed at 400 °C for 60 min indicated that the fracture surface of the aluminum layer was ductile type but the copper layer was a knife-edge without dimples and holes.