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Accumulative Roll Bonding of Pure Copper and IF Steel  [PDF]
Saeed Tamimi,Mostafa Ketabchi,Nader Parvin,Mehdi Sanjari,Augusto Lopes
International Journal of Metals , 2014, DOI: 10.1155/2014/179723
Abstract: Severe plastic deformation is a new method to produce ultrafine grain materials with enhanced mechanical properties. The main objective of this work is to investigate whether accumulative roll bonding (ARB) is an effective grain refinement technique for two engineering materials of pure copper and interstitial free (IF) steel strips. Additionally, the influence of severely plastic deformation imposed by ARB on the mechanical properties of these materials with different crystallographic structure is taken into account. For this purpose, a number of ARB processes were performed at elevated temperature on the materials with 50% of plastic deformation in each rolling pass. Hardness of the samples was measured using microhardness tests. It was found that both the ultimate grain size achieved, and the degree of bonding depend on the number of rolling passes and the total plastic deformation. The rolling process was stopped in the 4th cycle for copper and the 10th cycle for IF steel, until cracking of the edges became pronounced. The effects of process temperature and wire-brushing as significant parameters in ARB process on the mechanical behaviour of the samples were evaluated. 1. Introduction Recently, much attention has been directed to ultragrain refining of metallic materials, where the grain size is reduced to less than one micrometre. According to Hall-Petch relationship, it is expected that ultrafine grain (UFG) structure would result in higher strength [1, 2]. Producing high strength materials, particularly without alloying, is very important in economical point of view. Severe plastic deformation (SPD) techniques have been known in the last decades as effective methods to produce UFG materials. The efficiency of traditional SPD techniques has been carried out such as equal channel angular pressing (ECAP) and high-pressure torsion (HPT) for grain refinement of a number of metallic materials, for example, [3, 4]. It has been shown that the UFG microstructure can be achieved using these methods; however, the typical sizes of the samples deformed by ECAP and HPT are small [5]. Furthermore, these types of SPD processes require special and/or expensive equipment. In recent years, a number of alternative SPD technologies have been developed, including equal channel angular rolling, cyclic bending, and accumulative roll bonding (ARB) in which the mentioned limitations were partially omitted [5, 6]. These SPD processes have potential to be adopted by the industry to produce UFG materials in the form of large sheets, due to their possibility as continuous
Particle Based Alloying by Accumulative Roll Bonding in the System Al-Cu  [PDF]
Christian W. Schmidt,Patrick Kn?dler,Heinz Werner H?ppel,Mathias G?ken
Metals , 2011, DOI: 10.3390/met1010065
Abstract: The formation of alloys by particle reinforcement during accumulative roll bonding (ARB), and subsequent annealing, is introduced on the basis of the binary alloy system Al-Cu, where strength and electrical conductivity are examined in different microstructural states. An ultimate tensile strength (UTS) of 430 MPa for Al with 1.4 vol.% Cu was reached after three ARB cycles, which almost equals UTS of the commercially available Al-Cu alloy AA2017A with a similar copper content. Regarding electrical conductivity, the UFG structure had no significant influence. Alloying of aluminum with copper leads to a linear decrease in conductivity of 0.78 μΩ?cm/at.% following the Nordheim rule. On the copper-rich side, alloying with aluminum leads to a slight strengthening, but drastically reduces conductivity. A linear decrease of electrical conductivity of 1.19 μΩ?cm/at.% was obtained.
Microstructures and Mechanical Properties of Al/Mg Alloy Multilayered Composites Produced by Accumulative Roll Bonding

HSLiu,BZhang,GPZhang Shenyang National Laboratory for Materials Science,

材料科学技术学报 , 2011,
Abstract: Al/Mg alloy multilayered composites were produced successfully at the lower temperature (280°C) by accumulative roll bonding (ARB) processing technique. The microstructures of Al and Mg alloy layers were characterized by scanning electron microscopy and transmission electron microscopy. Vickers hardness and three-point bending tests were conducted to investigate mechanical properties of the composites. It is found that Vickers hardness, bending strength and stiffness modulus of the Al/Mg alloy multilayered composite increase with increasing the ARB pass. Delamination and crack propagation along the interface are the two main failure modes of the multilayered composite subjected to bending load. Strengthening and fracture mechanisms of the composite are analyzed.
Cracks Propagation as a Function of Grain Size Variants on Nanocrystalline Materials’ Yield Stress Produced by Accumulative Roll-Bonding  [PDF]
P. B. Sob, A. A. Alugongo, T. B. Tengen
Advances in Materials Physics and Chemistry (AMPC) , 2017, DOI: 10.4236/ampc.2017.72006
Abstract: Cracks are usually observed at the edge of materials deformed by accumulative roll bonding from conventional materials to nanostructure materials. The observed cracks then propagate in the materials during grain refinement. The cracks propagation affects the yield stress and the effective fracture energy of nanocrystalline materials. In this study, the impacts of crack propagation when measured as a function of grain size variants on nanocrystalline materials’ yield stress are investigated for a material deformed by accumulative roll-bonding. The study employs experimental data and theoretical concepts of severe plastic deformation and cracks processes in nanocrystalline materials. The current studies also focus on nano-cracks that will not lead to rapid materials failure during grain refinement. The study revealed that crack propagation varied as a function of grain size variants during grain refinement. The study also revealed that nano-crack increased during the deformation of nanostructured materials. The study also revealed that the effective fracture energy decreased as grain refinement took place. The study revealed that nanomaterials yield stress decreased with the increase in effective fracture energy. The current study suggests a theoretical model that shows the generation of nanomaterials cracks during grain refinement as a function of grain size variants. In the model, the cracks propagate on nanocrystalline materials due to the compressive load applied to a material. The model predicts that the generation of cracks as functions of grain size variants impacts the energy level in nanocrystalline materials.
Cyclic Deformation of Ultra-Fine Grained Commercial Purity Aluminum Processed by Accumulative Roll-Bonding  [PDF]
Charles C.F. Kwan,Zhirui Wang
Materials , 2013, DOI: 10.3390/ma6083469
Abstract: Accumulative Roll-Bonding (ARB) is one of the more recently developed techniques capable of producing bulk ultra-fine grained (ufg) metals. There are still many aspects of the behavior of ufg metals that lacks an in-depth understanding, such as a generalized view of the factors that govern the cyclic deformation mechanism(s). This study aims to advance the understanding of the cyclic deformation behavior of ufg metals through the systematic investigation of ARB processed aluminum upon cyclic loading. It was found that the cyclic softening response often reported for ufg metals is largely influenced by the microstructure stability as the cyclic softening response is facilitated by grain coarsening which becomes inhibited with highly stable microstructure. On one hand, shear bands resembling braids of dislocations trespassing multiple grains have been observed to operate for the accommodation of the imposed cyclic strain in cases where grain coarsening is largely restricted. On the other hand, it was found that the microstructure stability can be overcome at higher applied cyclic plastic strain levels, leading to grain coarsening and thus a cyclic softening response. The findings in this study have further confirmed that the cyclic softening behavior found in many ufg metals, which may be detrimental in practical applications, can be inhibited by improvements in the microstructure stability.
Mechanical Property and Fracture Behavior of Al/Mg Composite Produced by Accumulative Roll Bonding Technique  [PDF]
Chih-Chun Hsieh,Ming-Che Chen,Weite Wu
Journal of Composites , 2013, DOI: 10.1155/2013/748273
Abstract: The Al/Mg laminated composite was fabricated by an accumulative roll bonding (ARB) technique using Al-1100 and Mg-AZ31 at 573?K. Tensile properties along rolling direction under different ARB cycles were evaluated at the ambient temperature. The tensile strength of the Al/Mg composite increased gradually till three ARB cycle and then decreased after the fourth ARB cycles. Scanning electron microscopy (SEM) was used to investigate the microstructure evolution and the failure mechanism. The Al/Mg interface with interface angles between 30° and 35° has minimum tensile strength. A higher or lower interface angle improves the tensile strength, and the interface angle can be reduced by increasing the number of cycles in the ARB process. Thus, the crack at the coarse intermetallic compounds and rupture of the Al layer after fourth cycle caused the premature failure of the specimens during the tensile test. 1. Introduction In recent times, the deformation and stability of metallic multilayers and the elastic and plastic behavior of multilayers under stress are increasingly being studied by researchers. Despite a broad range of investigations that include, for example, the study of the dislocation behavior in nanoscale multilayers [1, 2], a common feature of most such studies is that the true strain involved in the deformation process is less than approximately 1. Due to the limited strain involved, substantial changes in the layer arrangement and layer thickness are rarely encountered. Processing of fine-grained microstructures, even amorphous phases, by severe plastic deformation (SPD) has received considerable interest as a technique for strengthening metallic materials without a substantial degradation of ductility. Fine-grained microstructures of many kinds of metallic materials have been obtained by SPD techniques. A novel intense straining process involved in SPD for bulk materials using rolling deformation, termed accumulative roll bonding (ARB), was developed recently [3–6]. In this process, the achieved strain is theoretically unlimited. The ARB process has been successfully applied to aluminum alloy systems [7–10], steel systems [11, 12], copper systems [13], and layer-composite systems [14–16]. Most materials processed by ARB in several cycles have structures with submicron grains and show very high strength at ambient temperature [7–11]. Al/Mg layer compounds were successfully produced via an ARB process [14]. Al/Mg layer compounds exhibited excellent mechanical properties and showed refined grains. Diffusion occurred at the interface of Al and Mg
Microstructure and mechanical properties of SiC-particle-strengthening tri-metal Al/Cu/Ni composite produced by accumulative roll bonding process  [PDF]
Moslem Tayyebi,Beitallah Eghbali
- , 2018, DOI: https://doi.org/10.1007/s12613-018-1579-6
Abstract: In this study, a multilayer Al/Ni/Cu composite reinforced with SiC particles was produced using an accumulative roll bonding (ARB) process with different cycles. The microstructure and mechanical properties of this composite were investigated using optical and scanning microscopy and hardness and tensile testing. The results show that by increasing the applied strain, the Al/Ni/Cu multilayer composite converted from layer features to near a particle-strengthening characteristic. After the fifth ARB cycle, a composite with a uniform distribution of reinforcements (Cu, Ni, and SiC) was fabricated. The tensile strength of the composite increased from the initial sandwich structure to the first ARB cycle and then decreased from the first to the third ARB cycle. Upon reaching five ARB cycles, the tensile strength of the composite increased again. The variation in the elongation of the composite exhibited a tendency similar to that of its tensile strength. It is observed that with increasing strain, the microhardness values of the Al, Cu, and Ni layers increased, and that the dominant fracture mechanisms of Al and Cu were dimple formation and ductile fracture. In contrast, brittle fracture in specific plains was the main characteristic of Ni fractures.
TOPICAL REVIEW Progress in cold roll bonding of metals
Long Li, Kotobu Nagai and Fuxing Yin
Science and Technology of Advanced Materials , 2008,
Abstract: Layered composite materials have become an increasingly interesting topic in industrial development. Cold roll bonding (CRB), as a solid phase method of bonding same or different metals by rolling at room temperature, has been widely used in manufacturing large layered composite sheets and foils. In this paper, we provide a brief overview of a technology using layered composite materials produced by CRB and discuss the suitability of this technology in the fabrication of layered composite materials. The effects of process parameters on bonding, mainly including process and surface preparation conditions, have been analyzed. Bonding between two sheets can be realized when deformation reduction reaches a threshold value. However, it is essential to remove surface contamination layers to produce a satisfactory bond in CRB. It has been suggested that the degreasing and then scratch brushing of surfaces create a strong bonding between the layers. Bonding mechanisms, in which the film theory is expressed as the major mechanism in CRB, as well as bonding theoretical models, have also been reviewed. It has also been showed that it is easy for fcc structure metals to bond compared with bcc and hcp structure metals. In addition, hardness on bonding same metals plays an important part in CRB. Applications of composites produced by CRB in industrial fields are briefly reviewed and possible developments of CRB in the future are also described.
Patterned Immobilization of Antibodies within Roll-to-Roll Hot Embossed Polymeric Microfluidic Channels  [PDF]
Belachew Feyssa, Christina Liedert, Liisa Kivimaki, Leena-Sisko Johansson, Heli Jantunen, Leena Hakalahti
PLOS ONE , 2013, DOI: 10.1371/journal.pone.0068918
Abstract: This paper describes a method for the patterned immobilization of capture antibodies into a microfluidic platform fabricated by roll-to-roll (R2R) hot embossing on poly (methyl methacrylate) (PMMA). Covalent attachment of antibodies was achieved by two sequential inkjet printing steps. First, a polyethyleneimine (PEI) layer was deposited onto oxygen plasma activated PMMA foil and further cross-linked with glutaraldehyde (GA) to provide an amine-reactive aldehyde surface (PEI-GA). This step was followed by a second deposition of antibody by overprinting on the PEI-GA patterned PMMA foil. The PEI polymer ink was first formulated to ensure stable drop formation in inkjet printing and the printed films were characterized using atomic force microscopy (AFM) and X-ray photoelectron spectroscopy (XPS). Anti-CRP antibody was patterned on PMMA foil by the developed method and bonded permanently with R2R hot embossed PMMA microchannels by solvent bonding lamination. The functionality of the immobilized antibody inside the microfluidic channel was evaluated by fluorescence-based sandwich immunoassay for detection of C-reactive protein (CRP). The antibody-antigen assay exhibited a good level of linearity over the range of 10 ng/ml to 500 ng/ml (R2 = 0.991) with a calculated detection limit of 5.2 ng/ml. The developed patterning method is straightforward, rapid and provides a versatile approach for creating multiple protein patterns in a single microfluidic channel for multiplexed immunoassays.
Analysis of roll stack deflection in a hot strip mill
Sikdar, Sudipta;John, Shylu;Pandit, Ashwin;Dasu, Raju;
Journal of the Brazilian Society of Mechanical Sciences and Engineering , 2007, DOI: 10.1590/S1678-58782007000300008
Abstract: predictive models are required to provide the bending set point for bending for the flatness control devices at rolling stands of finishing mill of hot strip mill (hsm). a simple model for roll stack deflection at the finishing mill has been illustrated where a modified misaka?s equation has been used to obtain mean flow-stress. investigation has been performed to understand the effect of width of roll on roll stack deflection. the bending on the deflection has been found to have a positive effect to reduce the amount of the stack deflection. the results from the sensitivity analysis of the roll width on roll deflection are also described.
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