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Cu/Ti laminated sheets with heterogeneous Ti layers are successfully fabricated by accumulative roll bonding (ARB). The microstructure during processing is characterized by scanning electron microscopy (SEM) and electron backscattered diffraction (EBSD). During the deformation of the constituent metals, the hard Ti layers neck preferentially but with a continuous layered structure. Upon four ARB cycles, there are five Ti layers with different microstructure states and grain sizes (from 1.3 to 0.5 μm) in the ARB4 sample. Tensile test of ARB4 sample indicates excellent comprehensive mechanical properties, compared with pure Cu and pure Ti, it has higher ultimate tensile strength (508 MPa), and the elongation (9.2%). In the result of loading–unloading–reloading test, there is a strain gradient during the tensile process due to heterogeneous existence of Ti layers, which produces a multilevel hetero‐deformation‐induced (HDI) stress strengthening and improves the coordinated deformation ability of the sample. Second, layered structure and interface with alternate strong and weak bonding can effectively hinder the propagation of cracks to outline higher strength with improved ductility. This structural design helps to prepare laminated materials sheet with excellent comprehensive mechanical properties through the ARB process. [ABSTRACT FROM AUTHOR]

In the present work, aluminum‐3% brass composite sheets are produced by accumulative roll bonding (ARB) process up to nine passes at ambient temperature. Evolution of rolling texture is studied by texture measurement using X‐ray diffraction method. The results show that ARB process leads to the formation of copper ({112} <111>) and Dillamore ({4 4 11} <11 11 8>) as the major texture components. The intensity of copper and Dillamore components enhances to values as high as 19 times that of random with increasing number of passes to 9. It is observed that the 5th pass is a transition in development of the texture components, after which the intensities undergo a drop. The textures are comparable to ARB process of high purity aluminum, indicating that the addition of 3% brass particles do not cause any significant change in the deformation behavior. Electron backscatter diffraction (EBSD) technique is used to examine the microstructure; the results reveal formation of ultrafine grains (UFG), starting in the 3rd pass and covers the entire structure after the 5th pass. The major mechanisms involved are identified as rotation of the sub‐grains, as well as grain boundary migration. [ABSTRACT FROM AUTHOR]

Ultrafine-grained AA1050 sheets have been produced by accumulative roll bonding (ARB). Two ARB processes have been compared in this study, one with preheating and the other without. In the preheated process the specimens were heated at 250°C for 3 minutes before ARB rolling. The microstructures of the ARB specimens were then investigated by transmission-electron-microscope (TEM) at different positions along the thickness, and it is found that the specimens deformed by ARB generally present a strong rolling texture with elongated grains in the middle of the sheet and roughly equiaxed grains near the surface. However, the equi-axed grains near the surface of the deformed sample had been impaired to some extent by preheating, and there was less grain refinement and more in-grain dislocations in the preheated specimens. A super-plasticity test was conducted on an Instron-type machine, with the results showing that pre-heating had improved superplasticity to a certain extent. [ABSTRACT FROM AUTHOR]

The paper aims to summarize the research on Laminar Metal Composites produced by Accumulative Roll Bonding. After some notes on the general subject, frequent material combinations and the issue of bonding are addressed. Then, the evolution of microstructure, texture, and mechanical properties typically observed in such materials is briefly summarized. Furthermore, the crucial aspect of layer continuity is discussed. In the main part, detailed experimental insight is provided for three representatives of different structural developments, namely Al2N/Al5N, Cu/Nb, and Ti/Al. The chosen systems represent different levels of component dissimilarity, as Al2N/Al5N is a combination of the same face centered cubic metal with varying purity while Cu/Nb and Ti/Al are combinations of face centered cubic with both body centered cubic and hexagonal close packed metals, respectively. As the layer thicknesses span different ranges, the composites also illustrate both the opportunities and experimental challenges of ARB Laminar Metal Composites. This review focuses on Laminar Metal Composites produced by Accumulative Roll Bonding. Three examples with dissimilar components (high purity Al/commercial purity Al, Cu/Nb, and Ti/Al) are provided and discussed in detail regarding microstructure, texture, mechanical properties, and layer continuity. [ABSTRACT FROM AUTHOR]

The focus of this paper is the designing of ultrafine‐grained aluminum/steel laminated metal composites for innovative lightweight materials concepts used for cyclic loading. These ultrafine‐grained composites are produced by the accumulative roll bonding process. Three different aluminum/steel composites are studied, where the position of the steel layers is varied, to investigate the influence of the layer architecture. The mechanical properties are measured in monotonic and cyclic three‐point bending tests. The influence of the meso‐ and microstructure are intensively studied by scanning electron microscope observations. Furthermore, the internal stresses during elastic straining are calculated by a finite element simulation. In the composites, both monotonic and cyclic mechanical properties are strongly increased and are clearly higher as expected by a linear rule of mixtures of the constituent materials. This increase is particularly high for the fatigue properties resulting in a strongly enhanced specific fatigue limit of the composites. The focus of this paper is the designing of ultrafine‐grained (UFG) aluminum/steel (AA5754/DC05) laminated metal composites for innovative lightweight materials concepts used for cyclic loading. Three different composites are produced, where the distance of the steel layers to the outer surface is gradually reduced (L1/4, L1/8, L0). The most favorable layer architecture strongly depends on the applied cyclic stress amplitude. At higher stress amplitudes, the composite with surface layers of steel (L0) reveal the longest fatigue lives. However, at lower stress amplitudes, the composite with aluminum as outer layers and a near surface steel layers (L1/8) shows the best fatigue life. [ABSTRACT FROM AUTHOR]