Accumulative Roll Bonding Passes Research Articles

FABRICATION OF AA1100/Fl2O3 COMPOSITE STRIPS AND THE IMPROVEMENT OF THEIR ELECTROMAGNETIC, MECHANICAL AND FRACTURE PROPERTIES

In this study, forming limit diagrams (FLDs), fracture toughness (FT), mechanical, magnetic, and electro-physical properties of Al/Fe2O3 composites have been investigated experimentally. Accumulative-roll-bonding (ARB) process was used to manufacture composite samples. Then, Al/Fe2O3 composites have been produced at 300∘C up to eight ARB passes. Also, magnetic composites have been fabricated with 0, 5% and 10[Formula: see text]wt.% of particles. The interlayer bonding quality was improved at higher passes. By studying the SEM rapture morphology, it was shown that the rapture mode changed to shear ductile for samples with more passes. For composite samples fabricated at higher passes and in comparison with the annealed sample, elongated dimples were turned to shallow dimples. FLDs area as the main forming criterion dropped severely after pass one and then began to improve at higher passes. Fracture test results showed that after the 8th pass, the value of FT improved gradually to the maximum value of 34.3[Formula: see text]MPam[Formula: see text].

Effect of ARB process on the plane stress fracture toughness, creep properties and forming limit diagram of Aluminum/BN/Copper composite strips

Abstract In the present study, Al/BN/Cu bimetal composite strips were fabricated via the accumulative roll bonding (ARB) process. Then, fracture toughness, mechanical properties, bonding strength, forming limit diagram (FLD), and creep properties have been studied via experimental techniques. The study of creep behavior and mechanical properties showed a formation of a 17 μm atomic diffusion layer at the interface during ARB under three creep loading conditions namely 35 MPa at 225 °C, 35 MPa at 275 °C, and 30 MPa at 225 °C. The tensile strength of samples improved to 144 MPa which was about 234% in comparison with the primary Al monolithic sample. It was observed by the SEM that the fracture types changed to shear kind after higher passes including prominent effects on the fracture morphology. FLD curve dropped severely after the first ARB pass and then began to enhance at higher passes. The fracture toughness value of 30 MPa m1/2 was achieved after ten ARB passes. An intermetallic composition was created near Al. The creep failure time did decline by 44% and the stress level decreased by 13% at a constant temperature. It can be concluded that applied temperature and stress effect on creep properties especially leads to increasing the slope of creep curves with higher stresses. This trend was opposite for the creep temperature at higher temperature levels. Moreover, dynamic recrystallization was observed through the crystalline structure of samples.

High-temperature tribological behavior of the Al/Mg/Cu multilayered composite produced by the severe plastic deformation

In the current research, the microstructure and wear behavior of Al/Mg/Cu multilayered composite at high temperatures were investigated. For this purpose, the Al/Mg/Cu composite was produced by the accumulative roll bonding (ARB) process and continued until the sixth pass at ambient temperature. The hot wear tests were performed at loads of 10, 20, and 40 N at 100, 150, and 250 °C for different passes. The findings demonstrated that with the increase of ARB passes, the wear rate decreased. So under 40 N at 100, 150, and 250 °C, the wear rate in the sixth pass decreased by 53 %, 65 %, and 76 %, respectively, compared to the first pass. The examination of the worn surfaces showed at 100 °C under high loads, fatigue wear was dominant. At 150 °C, oxidation was the main wear mechanism. The presence of oxidized grooves on the surface showed that the abrasive wear encouraged oxidation. At 250 °C under 40 N, inhomogeneous oxidation was the main wear mechanism of the samples. So that aluminum and magnesium regions were oxidized and copper areas remained un-oxidized like isolated islands.

Effect of Heat Treatment on the Interfacial Structure and Microstructure of Al/Al/Cu Composites Prepared by Different Accumulative Roll Bonding Passes

The effects of heat treatment ((300–500 °C) × 30 min) on the interfacial structure, microstructure, and tensile properties of Al4343/Al3003/Cu composites prepared by different accumulative roll bonding (ARB) passes are studied by scanning electron microscopy, energy dispersion spectrometry, electron backscattered diffraction, and tensile tests at room temperature. The results show that the total thickness of the diffusion layer at the Al3003/Cu interface in the same ARB pass Al/Al/Cu composite increases with the increase in temperature. At the same temperature, the total thickness of the diffusion layer at the Al3003/Cu interface increases from ARB0 to ARB3 passes and decreases at ARB5 passes. In the same ARB pass Al/Al/Cu composites, the grains of Al4343 grow with the increase of temperature; the grain of Al3003 increases slightly from 300 to 400 °C, and grows along the interface direction after 500 °C. After 400 and 500 °C, the final average grain size of Cu decreases from ARB0 to ARB3 passes and increases slightly at ARB5 passes. The tensile properties of the composites are affected by recovery and recrystallization at lower temperatures and ARB passes, and by the total thickness and volume fraction of the diffusion layer at higher temperatures and ARB passes.

Microstructural evolution and mechanical properties of aluminum-graphite composites processed via accumulative roll bonding

In the present work, the aluminum-graphite metal matrix composites were fabricated via accumulative roll bonding (ARB). The graphite powder particles of <50 μm were introduced into aluminum in three different weight percentages. The effect of graphite on the evolution of microstructure, interface formation, and mechanical properties was studied. The microstructural investigation revealed that the amount of graphite played a vital role. A better particle distribution was observed for 1.25 and 1.5 wt%. However, a further increase in the reinforcement to 2.2 wt% shows longer flaky graphite with comparatively sharing a larger interface area with the matrix aluminum. An FE-SEM/EDS (Field Emission-Scanning electron microscopy/Energy dispersive Spectroscopy) line mapping at the aluminum-graphite interface confirmed an intact sound interface with better adherence properties. The ultimate tensile strength of the composites drastically improved with an increasing number of ARB passes. The FE-SEM taken over the fractured surface of the composite revealed that the ARBed Al-1100 and the composites failed in ductile mode. It was observed that the graphite particle was the primary source of nucleation in the composites. The voids have nucleated at the particle-matrix interface, followed by their growth and coalescence.

Plastic deformation and fracture of AlMg6/CNT composite: A damage evolution model coupled with a dislocation-based deformation model

Understanding the plastic deformation and fracture behavior of Carbon nanotube (CNT)-reinforced aluminum composites is crucial for determining the factors controlling their strength and ductility. This article presents a novel approach by proposing a coupled micromechanical dislocation-based constitutive model combined with the Gurson-Tvergaard-Needleman (GTN) damage evolution model. The objective of this research is to accurately predict the load-displacement behavior of an AlMg6/CNT composite, which is manufactured through accumulative roll bonding (ARB), from yield to fracture. The study investigates the correlations between the number of ARB passes, which affects the dislocation density of the matrix, and the distribution of CNTs in the composite, with the GTN parameters. The analysis reveals that the volume fraction of void nucleating particles (fN) is a critical parameter influencing the ductility of the composite ductility. Initially, due to CNT agglomeration, they act as nucleation sites for damage, resulting in an increase in fN and a decrease in ductility. However, as the number of ARB passes increases, leading to a homogeneous CNT distribution, fN decreases, and CNTs contribute to improved strength and ductility of the composite. The proposed model accurately predicts the load-displacement curve of the composite during uniaxial tensile testing, taking into account the effect of ARB passes. The research findings provide insights for future extensions of the GTN model, aimed at enhancing its theoretical framework and applicability in the field.

New aspects of solid-state welding in the aluminium accumulative roll bonding

The phenomena in solid-state welding (SSW) of metals during accumulative roll bonding (ARB) are analysed. The basic mechanism in SSW is described by the ‘film theory’, where superficial oxide layers/cover layers of metals fracture when submitted to elongations, the material on both sides of the sheets to be joined are extruded through these fractures and opposing virgin surfaces touch and weld. Present results reveal new aspects of these phenomena: the presence of ‘mountain ridges’ on delaminated surfaces after ARB, bonding regions along the rolling direction and the flattening of the geometric characteristics of delaminated surfaces as the number of ARB passes rises. A model is proposed for the development of the bonds along the rolling direction.

Investigation on Various Ceramic Nanoparticles Reinforced Aluminum Matrix Composites via Accumulative Roll Bonding and Cryorolling

Accumulative roll bonding (ARB) and cryorolling (CR) processes are used to fabricate three kinds of composites of AA1050 reinforced with SiCp and TiCp, to become the Al‐SiCp, Al‐TiCp, and Al‐SiCp‐TiCp composites. The effects of reinforced particles and different passes of ARB and CR on mechanical properties, microstructure, and particle distribution are studied. The microstructure shows the uniform distribution of particulates, decreased porosity, and excellent bonding between particle and matrix as the rolling cycles increased. Mechanical properties of the ARBed and cryorolled sheets are examined, and samples are compared with matrix alloy and composites. The findings demonstrate that the Al‐SiCp, Al‐TiCp, and Al‐SiCp‐TiCp composites improve the elastic modulus, yield strength, and hardness. After comparing the results of composites, the best combination of hardness, yield strength, ultimate tensile strength, toughness, and young modulus base composite has been chosen. Al‐TiCp and Al‐SiCp composites demonstrate ductile fracture behavior, as observed through SEM testing, while Al‐SiCp‐TiCp composite sample exhibits a bimodal fracture. This composite should aid in the creation of lightweight composites for use in aeronautical applications.

ELECTROMAGNETIC PROPERTIES, FORMING LIMIT DIAGRAMS AND FRACTURE TOUGHNESS OF LAMINATED Al/Fe2O3 COMPOSITES

In this study, electrophysical, electromagnetic and mechanical properties, fracture toughness and forming limit diagram (FLD) of Al base composite samples have been studied experimentally. All samples have been fabricated via accumulative roll bonding (ARB) process. To this purpose, AA1060/ Fe2O3 composite strips with thickness of 1 mm have been fabricated with up to eight ARB passes at 300[Formula: see text]C. In this study, magnetic Al/Fe2O3 composites reinforced with 0, 5% and 10 wt.% of Fe2O3 particles have been manufactured via ARB. The microstructure was studied by optical microscopy (OM). Also, by decreasing the thickness of layers at higher number of passes (increasing the plastic strain), the bonding quality among the layers was improved. Scanning electron microscopy (SEM) fracture surface morphology of samples after the tensile test showed that by increasing the passes, the fracture style (mode) converted to shear ductile at higher ARB passes. So, deep dimples shrink slowly and their number and depth decreased relative to the annealed sample. As the criterion of formability, the area under the FLDs dropped sharply after the first pass and then improved by increasing the passes. Results of fracture test have shown that the value of fracture toughness has been enhanced continually to the maximum value of 34.3 MPam[Formula: see text] at the 8th pass.

Effect of Al2O3 particle content on microstructure and mechanical properties of 1060Al/Al–Al2O3 composites fabricated by cold spraying and accumulative roll bonding

1060Al/Al–Al2O3 laminated particle-reinforced aluminum matrix composites (LPRAMCs) were successfully prepared using a combination of cold spraying (CS) and accumulative roll bonding (ARB) techniques, exhibiting a synergistic improvement in strength and plasticity. The effects of Al2O3 particle content on the microstructure, tensile properties and fracture morphology of LPRAMCs were studied. The results showed that compared with the 1# composites with higher Al2O3 particle content (20.1 vol%), the 2# composites with lower Al2O3 particle content (8.4 vol%) exhibited delayed necking fracture during the ARB process, with greater elongation (El) but lower ultimate tensile strength (UTS). After 5 passes of ARB, the UTS and El of the 1# and 2# composites were 345 MPa, 16.1%, and 293 MPa, 22.2%, respectively. This suggests that the mechanical properties of the Al–Al2O3 deposited layer have a significant impact on the mechanical properties of LPRAMCs. With an increase in ARB passes, the fracture mode of the LPRAMCs shifted from brittle to ductile fracture, displayed by equiaxed and shear dimples. These findings can provide novel insights and theoretical foundations for optimizing the mechanical properties of Al matrix composites.

The role of strain path changes on the microstructure, texture, and mechanical properties of unidirectionally and cross-accumulative roll-bonded (ARBed) aluminum

Accumulative roll bonding (ARB) was carried out via unidirectional (UARB) and cross (CARB) routes to investigate the role of strain path variation on the microstructure, texture, and mechanical properties of commercially pure Al sheets. The microstructure and crystallographic texture were studied using the X-ray diffraction method. Microstructural observations indicated that the 90-degree sample rotation between consecutive passes led to higher dislocation density in the CARB-processed samples. Moreover, the grain size was remarkably decreased to 193 nm by eight cycles of the CARB technique, showing a reduction of 99% compared to the initially annealed specimen. Macrotexture measurements demonstrated that a strong Cube {001} <100> component (16 × R), observed in the starting Al, disappeared after the first ARB pass. In contrast to the UARBed strips, the Goss/Brass {011} <115>, A {011} <111>, and P {011} <122> components were introduced by sample rotation in CARBed aluminum sheets. The mechanical properties of the processed materials were evaluated using microhardness and uniaxial tensile tests. It was found that the hardness was continuously increased by increasing the number of the pass in both routes. A dramatic drop in the elongation after the first cycle gave rise to a toughness of 6.2 MJ m−3. However, increasing the number of cycles resulted in an increase of about 230% in toughness in the eight-cycle processed specimens.

Prediction of the tensile properties of ultrafine grained Al–SiC nanocomposites using machine learning

We discovered and analyzed the new prediction model by using machine learning (ML) for the tensile strength of aluminum nanocomposites reinforced with μ-SiC particles fabricated by accumulative roll bonding (ARB). The effect of the number of cycles and SiC content on the microstructure, phase analysis, tensile, and hardness properties have been investigated for the ARBed sheets and their composites. The experimental results showed the distribution of SiC particles improved by increasing ARB passes. The ARB approach greatly enhanced the ultimate tensile strength (UTS), yield strength (YS), and hardness. The UTS achieved was 254 MPa for 4% SiC after 9 ARB cycles. The hardness values of the ARBed AA1050, and AA1050-4 wt% SiC are 60, and 76.5, respectively, after 9 ARB cycles. The modified version of random vector functional link based on Growth Optimizer Algorithm is developed as a machine-learning model to predict the tensile properties of the produced composites. The efficiency of the developed ML model is evaluated with other methods according to the performance criteria.

On the understanding and prediction of tribological properties of Al-TiO2 nanocomposites using artificial neural network

Due to the influence of the manufacturing process on the composite’s wear properties, mathematical models cannot accurately predict the wear rates and coefficients of friction of composite materials. As a result, this work provides a deeper comprehension of the tribological properties of Al-TiO2 nanocomposites with varying TiO2 content tested at varying sliding loads as well as improved predictability. Accumulative roll bonding (ARB) was used to create Al-TiO2 nanocomposites that had good TiO2 nanoparticle dispersion in the matrix. The pin-on-disc test was used to measure their wear rates and coefficient of friction. A neural network model was used to predict the wear rates and the coefficient of friction because there was a correlation between the composite morphology, hardness, and microstructure, as well as the evolution of the tribological properties. Due to the uniform distribution of TiO2 nanoparticles within the composite and the saturation of grain refinement in the Al matrix, it was experimentally demonstrated that wear rates decrease as the number of ARB passes increases until a plateau is reached. After five ARB passes, the composite containing 3% TiO2 nanoparticles achieved the maximum hardness improvement of 153.7%. While the same composite’s wear rates decrease from 3.7 × 10−3 g/m for pure Al to 1.1 × 10−3 g/m at 5 N load. For each of the produced composites that were subjected to four distinct wear loads, the artificial neural network model was able to accurately predict the wear rates and coefficient of friction, achieving determination coefficient R2 values of 0.9766 and 0.9866, respectively, for the wear rates and coefficient of friction.

Prediction of wear rates of Al-TiO2 nanocomposites using artificial neural network modified with particle swarm optimization algorithm

The prediction of the wear rates and coefficient of friction of composite materials is relatively complex using mathematical models due to the effect of the manufacturing process on the wear properties of the composite. Therefore, this work presents a rapid reliable tool based on neural network modified with particle swarm optimizer to predict the wear rates and coefficient of friction of Al-TiO2 nanocomposite manufactured using accumulative roll bonding (ARB). The wear rates and coefficient of the produced composites were computed using pin-on-disc and correlated with the composite morphology, hardness and microstructure. Experimentally, it was demonstrated that the hardness and wear rates reduce with increasing the number of ARB passes until a plateau was achieved due to the uniform distribution of TiO2 nanoparticles inside the composite and the saturation of grain refinement in the Al matrix. The maximum hardness improvement was 153.7% for composite containing 3% TiO2 nanoparticles after 5 ARB passes. While the wear rates of the same composite tested at 5 N load reduces from 3.7 × 10−3 g/m for pure Al to 1.1 × 10−3 g/m. The proposed model was able to predict the wear rates and coefficient of friction for all the produced composites tested at four different wear loads with excellent accuracy reaching R2 equal 0.9766 and 0.9866 for the wear rates and coefficient of friction, respectively.

A novel Cu-carbon nanotube sheet composite manufactured via the ARB process: A microstructural and mechanical study

A Cu matrix composite was designed and produced successfully by adding carbon nanotubes (CNTs) as reinforcement particles. The accumulative roll bonding (ARB) process was used to introduce the material in the shape of the sheet. The process was repeated up to five ARB cycles to obtain a uniform composite with good mechanical properties. Different amounts of CNTs were added to the matrix of Cu in order to evaluate the behavior of the CNTs in the matrix of the Cu. Microstructural evaluations confirmed that by increasing the ARB cycles, a uniform distribution of the CNTs was achieved. However, for Cu-1%CNT considerable numbers of unbonded areas led to weak bonding. Also, the material responded differently to the applied tensile test during loading. For low amounts of CNT-contained composites, the ultimate tensile strength (UTS) was increased in each ARB pass, but, for Cu-1%CNT composite, the UTS was the lowest. Also, microscopy observations were used to study the distribution/configuration of CNTs. The weak bonding of the Cu layers in some spots was attributed to the agglomeration of CNTs between the layers. Fractography of the samples after the tensile test, also, showed remarkable separation between the unbonded layers.

On the prediction of the mechanical properties of ultrafine grain Al-TiO2 nanocomposites using a modified long-short term memory model with beluga whale optimizer

Mechanical properties of fine grain nanocomposites differ from those of conventional composites due to the in situ effect caused by the addition of nanoparticle reinforcement and the complexity of strengthening mechanisms, which make their prediction using conventional analytical and numerical model is relatively difficult. Therefore, this work presents a rapid reliable machine learning model based on long-short term memory model modified with beluga whale optimizer to predict the mechanical properties of ultrafine grain Al-TiO2 nanocomposite manufactured using accumulative roll bonding (ARB). The mechanical properties were evaluated using tensile tests and correlated with the composite microstructure and hardness. Experimentally, it was demonstrated that the tensile strength increases with increasing the number of ARB passes until a plateau was achieved due to the uniform distribution of TiO2 nanoparticles inside the composite and the saturation of grain refinement in the Al matrix. The maximum tensile achieved was 270 MPa for composite containing 3% TiO2 nanoparticles after 5 ARB passes compared to 90.5 MPa for the raw Al. The proposed model was able to predict the yield and ultimate strengths, elongation, and hardness for all the produced composites tested with excellent accuracy reaching R2 equal 0.9955, 0.9952, 0.9859, and 0.9975, respectively, which is way better than other models.

Microstructure-Based Modeling and Mechanical Characteristics of Accumulative Roll Bonded Al Nanocomposites with SiC Nanoparticles

This research work aims to fabricate the Al-4 wt.% SiC nanocomposite using the accumulative roll bonding (ARB) technique. Moreover, a finite element model based on real microstructure representative volume element representation and cohesive zone modeling was developed to predict the mechanical response of the produced composites. The results demonstrated that SiC particles were homogenously distributed inside the Al matrix after five passes. The tensile strength and hardness were improved by increasing the number of ARB passes. The microhardness of an Al-4%SiC composite subjected to five ARB passes was increased to 67 HV compared to 53 HV for Al sheets subjected to the same rolling process. Moreover, owing to greater bonding and grain refinement, tensile strength was increased by a factor of three compared to pure Al. The result of the proposed micro-model successfully predicts the experimentally obtained results of the Al–SiC macro composite. The numerically obtained stress–strain curve was comparable with the experimental one. The results also showed that the size of the used RVE was significantly influential in the prediction of the stress–strain behavior.

Microstructure evolution and mechanical behavior of α/β alternative Mg–Li alloy composite sheets with different initial thickness ratios prepared by accumulative roll bonding

α/β alternative Mg–Li composite sheets with different initial thickness ratio of α to β (H) were prepared by accumulative roll-bonding (ARB). The hard layer necking, microstructure evolution and the strain hardening sequence of the α/β alloys in the composite sheets during the ARB process were studied by optical microscopy (OM), transmission electron microscopy (TEM), X-ray diffraction (XRD), microhardness and tensile test. The results showed that, with the increase of H, the necking of the LA51 layer was relieved, and the grains of the two alloys were gradually refined. With the increase of ARB passes and H, the strength of the composite sheets increased first and then decreased, and the plasticity decreased first and then increased. When H = 1, the ARB3 composite sheet possesses the ultimate tensile strength (UTS), yield strength (YS) and elongation (EL) of 286 ± 1 MPa, 262 ± 6 MPa and 6.4 ± 0.1%, respectively. During the ARB process, the work hardening of the LA141 layer first increased, then that of the LA51 layer increased gradually, and finally that of the two alloy layers increased simultaneously.

Study of mechanical properties and wear resistance of nanostructured Al 1100/TiO2 nanocomposite processed by accumulative roll bonding

Aluminum (Al) composites have been extensively developed for automotive applications due to their high specific strength. Therefore, in this study, an Al-titanium dioxide (TiO2) nanocomposite was processed using the accumulative roll bonding (ARB) process. The mechanical characteristics of monolithic and nanocomposites specimens made with 0, 1, 2, and 3 wt% TiO2 nanoparticles as reinforcement were studied at several ARB passes. According to the microstructure of the composites, rolling after five passes achieves a homogenous distribution of reinforcement particles, ultrafine and elongated grains of the matrix. After five ARB passes, the TiO2 particles were uniformly dispersed. Finally, scanning electron microscopy and energy dispersive spectroscopy revealed that the Al-TiO2 nanocomposite had an appropriate dispersion of TiO2 nanoparticles. Vickers microhardness improves as the number of accumulative roll bonding passes increases. Furthermore, after five passes, Vickers microhardness testing revealed that the sample with 3%TiO2 has the greatest hardness value of 112 HV, which is significantly greater than the 44 HV hardness value of the ARB-processed aluminum. The mechanical properties of the specimens, yield and ultimate strengths, improved with the addition of TiO2 nanoparticles. Due to good bonding among the components, mechanical parameters such as microhardness and tensile strength were more than three times better than the Al matrix.

Effect of concurrent accumulative roll bonding (ARB) process and various heat treatment on the microstructure, texture and mechanical properties of AA1050 sheets

This study investigated the microstructure, texture, and mechanical properties of 1050 aluminum alloy sheets that underwent the accumulative roll bonding (ARB) method. The ARB proceeded up to eight passes in three ways: conventional process, preheat between rolling passes (preheating) or anneal between rolling passes (annealing). Heat treatment was done between the ARB passes for 5 min at 150 °C. The mean grain width of the 1050 Al sheet that was 11 μm before ARB, decreased to 295.73 nm, 317.33 nm, or 339.23 nm after six ARB passes in the conventional process, annealed or preheated conditions, respectively. Concurrent heat treatments cause a decrease in the strength of the texture components of Al sheets that were elaborated by the ARB method. Even though conventional and annealed processes successfully enhanced the microhardness by ∼80% and tripled the tensile strength, these improvements were weaker in the preheated condition than the other conditions due to dynamic recovery.