Nanostructured Bulk Copper Fabricated by Accumulative Roll Bonding

2007 ◽  
Vol 7 (11) ◽  
pp. 3985-3989 ◽  
Author(s):  
Naoki Takata ◽  
Seong-Hee Lee ◽  
Cha-Yong Lim ◽  
Sang-Shik Kim ◽  
Nobuhiro Tsuji
Keyword(s):  
Accumulative Roll Bonding ◽  
Uniform Elongation ◽  
Copper Alloys ◽  
High Strength ◽  
Total Elongation ◽  
Equivalent Strain ◽  
Boundary Structure ◽  
Roll Bonding ◽  
Lamella Spacing ◽  
Plastic Deformation Process

In this study, we tried to fabricate the nanostructured bulk copper alloys by a severe plastic deformation process. The sheets of copper alloys (OFC, PMC90, and DLP) were heavily deformed to an equivalent strain of 6.4 by the accumulative roll-bonding (ARB) process. The microstructure and the mechanical property of the fabricated specimens were systematically investigated. The microstructure was finely subdivided with increasing the equivalent strain by the ARB process. The severely deformed copper alloys exhibited the ultrafine lamellar boundary structure where the mean lamella spacing was about 200 nm. The strength significantly increased with decreasing the lamella spacing in the ARB processed copper alloys. Especially, the tensile strength of the DLP alloys ARB processed by 8 cycles (the equivalent strain of 6.4) reached to 520 MPa, which was about three times higher than that of same materials with conventional grain size of 10–100 μm. On the other hand, the total elongation greatly dropped only by 1 ARB cycle corresponding to an equivalent strain of 0.8, which was around 3%. However, the total elongation increased again with increasing the number of the ARB cycle, and it reached to 10% after 8 cycles. The recovery of the total elongation could be recognized in all studied copper alloys. The obtained stress–strain curves showed that the improvement of the total elongation was caused by the increase in the post-uniform elongation. It can be concluded that the nanostructured copper alloys sheets having high strength without a large loss of ductility could be fabricated by the ARB process.

Mechanical Properties and Aging Behavior of Ultrafine Grained Al-Ag Alloy Fabricated by Accumulative Roll-Bonding

2014 ◽  
Vol 794-796 ◽  
pp. 851-856
Author(s):  
Tadashiege Nagae ◽  
Nobuhiro Tsuji ◽  
Daisuke Terada
Keyword(s):  
Mechanical Properties ◽  
Grain Refinement ◽  
Accumulative Roll Bonding ◽  
Precipitation Hardening ◽  
Tensile Elongation ◽  
Solution Treatment ◽  
High Strength ◽  
Subsequent Aging ◽  
Roll Bonding ◽  
Ultrafine Grained

Accumulative roll-bonding (ARB) process is one of the severe plastic deformation processes for fabricating ultrafine grained materials that exhibit high strength. In aluminum alloys, aging heat treatment has been an important process for hardening materials. In order to achieve good mechanical properties through the combination of grain refinement hardening and precipitation hardening, an Al-4.2wt%Ag binary alloy was used in the present study. After a solution treatment at 550°C for 1.5hr, the alloy was severely deformed by the ARB process at room temperature (RT) up to 6 cycles (equivalent strain of 4.8). The specimens ARB-processed by various cycles (various strains) were subsequently aged at 100, 150, 200, 250°C, and RT. The hardness of the solution treated (ST) specimen increased by aging. On the other hand, hardness of the ARB processed specimen decreased after aging at high temperatures such as 250°C. This was probably due to coarsening of precipitates or/and matrix grains. The specimen aged at lower temperature showed higher hardness. The maximum harnesses achieved by aging for the ST specimen, the specimens ARB processed by 2 cycles, 4 cycles and 6 cycles were 55HV, 71HV, 69HV and 65HV, respectively. By tensile tests it was shown that the strength increased by the ARB process though the elongation decreased significantly. However, it was found that the tensile elongation of the ARB processed specimens was improved by aging without sacrificing the strength. The results suggest that the Al-Ag alloy having large elongation as well as high strength can be realized by the combination of the ARB process for grain refinement and the subsequent aging for precipitation hardening.

Structure and mechanical properties of Ni/Ti multilayered composites produced by accumulative roll-bonding process

2019 ◽  
Vol 54 (8) ◽  
pp. 1119-1126
Author(s):  
Mohammad Mokhles ◽  
Morteza Hosseini ◽  
Habib Danesh-Manesh ◽  
Seyed Mojtaba Zebarjad
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Scanning Electron Microscopy ◽  
Accumulative Roll Bonding ◽  
Tensile Tests ◽  
Total Elongation ◽  
Uniaxial Tensile ◽  
Roll Bonding ◽  
Multilayered Composites ◽  
Scanning Electron

This research studies the structure and mechanical properties of Ni/Ti multilayered composites produced from commercial pure Ni and Ti foils by accumulative roll-bonding technique. To investigate these properties, scanning electron microscopy, Vickers microhardness, and uniaxial tensile tests were conducted at different processing cycles. Studies showed that in terms of structure, Ni and Ti layers maintain their continuity even up to 10 cycles of accumulative roll-bonding. Moreover, the energy-dispersive spectroscopy in scanning electron microscopy detected no deformation induced diffusion or reactive interfacial zones. It was found that by increasing the accumulative roll-bonding cycles, tensile and yield strengths as well as the hardness of the composite enhance and the total elongation reduces continuously.

Nano-Structured High Purity Copper Processed by Accumulative Roll-Bonding

2006 ◽  
Vol 317-318 ◽  
pp. 239-242 ◽  
Author(s):  
Seong Hee Lee ◽  
Seung Zeon Han ◽  
Cha Yong Lim
Keyword(s):  
Accumulative Roll Bonding ◽  
Equivalent Strain ◽  
Initial Value ◽  
Thickness Strain ◽  
Equivalent Thickness ◽  
Roll Bonding ◽  
Ultrafine Grains ◽  
The Third ◽  
Cold Roll ◽  
Purity Copper

Accumulative roll-bonding (ARB) process was applied to an oxygen free copper for improvement of the mechanical properties via ultra grain refinement to nanometer order level. Two copper sheets 1mm thick, 30mm wide and 300mm long are degreased and wire-brushed for sound bonding. The sheets are then stacked to each other, and cold-roll-bonded by 50% reduction rolling. The sheet is then cut to the two pieces of same length and the same procedure was repeated to the sheets. The ARB process up to eight cycles (an equivalent thickness strain of 6.4) is successfully performed at ambient temperature. TEM observation reveals that ultrafine grains, hardly containing the dislocation interior, begin to develop at the third cycle, and after the sixth cycle they cover most of regions of samples. The morphology of ultrafine grains formed is different from that of aluminum alloys. Tensile strength of the ARB-processed copper increases with the equivalent strain up to a strain of ~3.2, in which it reached 390 MPa, ~2.1 times higher than the initial value. However, the strength hardly changed at the strain above ~3.2.

scholarly journals Manufacturing of high-strength multilayered composite by accumulative roll bonding

2020 ◽  
Vol 6 (12) ◽  
pp. 1265e6 ◽  
Author(s):  
M Tayyebi ◽  
D Rahmatabadi ◽  
M Adhami ◽  
R Hashemi
Keyword(s):  
Accumulative Roll Bonding ◽  
High Strength ◽  
Roll Bonding ◽  
Multilayered Composite

Accumulative Roll Bonding: Forming Behavior, Tailored Properties and Upscaling Approach

2014 ◽  
Vol 907 ◽  
pp. 3-16
Author(s):  
Marion Merklein ◽  
Wolfgang Böhm
Keyword(s):  
Finite Element ◽  
Accumulative Roll Bonding ◽  
High Strength ◽  
Accurate Information ◽  
Plastic Behavior ◽  
Stress Strain ◽  
Element Analysis ◽  
Roll Bonding ◽  
Heat Treated ◽  
Strain Paths

The Accumulative Roll Bonding (ARB) process enables the manufacturing of high strength sheet metals with outstanding mechanical properties by repeated rolling. However, the significant increase in strength leads to loss in ductility, especially regarding aluminum alloys of the 6000 series. The low formability obviously limits the implementation of these sheet products for formed components in automotive applications. To enhance formability, a local short term heat treatment according to the Tailored Heat Treated Blanks technology is used. For the finite element based design of forming operations accurate information about the plastic behavior of these tailored materials is required. Therefore, different stress - strain paths are considered using the tensile test and the layer compression test. In this context, heat treated and non-heat treated specimens out of ARB processed AA6016 were tested at room temperature. With the experimental results true stress strain curves and yield loci determined from different criteria and represented in a principal stress state were established. Regarding the experimental setup of the ARB process, an upscaling is essential for the production of sufficiently large strips to cut out blanks for the forming of components such as B-pillars. However, this requires the adaptation of the different process steps of the ARB process. In this context, the surface treatment before rolling of such large sheets is investigated, since it is particularly relevant for obtaining a strong bonding between the sheets. Another aspect is the investigation of the rolling process using the finite element analysis. In this regard, a thermal mechanical coupled simulation model of the roll bonding operation will be developed for the evaluation of different material combinations, different process temperatures and varying roller geometries. These investigations will enable the production of lightweight automotive components made of ARB processed high strength aluminum sheet metal with tailored properties.

Bulk Mechanical Alloying of Al/Fe Multilayer by Accumulative Roll-Bonding Process

2007 ◽  
Vol 26-28 ◽  
pp. 695-698 ◽  
Author(s):  
Takuro Nakamura ◽  
Hiromoto Kitahara ◽  
Jung Goo Lee ◽  
Nobuhiro Tsuji
Keyword(s):  
Solid Solution ◽  
Intermetallic Compound ◽  
Mechanical Alloying ◽  
Accumulative Roll Bonding ◽  
Supersaturated Solid Solution ◽  
Shear Bands ◽  
Equivalent Strain ◽  
Bonding Process ◽  
Accumulative Roll Bonding Process ◽  
Roll Bonding

Pure Al (99%) and pure Fe (99.5%) sheets were mutually stacked and severely deformed up to equivalent strain of 16 by the accumulative roll bonding (ARB) process in an attempt to achieve bulk mechanical alloying. The deformation was carried out at RT. The Al/Fe sheets ARB processed by 1 cycle showed a number of shear bands penetrating the stacked layers. The Fe layers, which were harder than the Al layers, were subdivided by the shear bands into diamond-shaped regions. Dissolution of Fe into Al was observed and a supersaturated solid solution was formed in the specimen ARB processed by 10 cycles. It was also found that local amorphization occurred at interface regions via formation of Al5Fe2 intermetallic compound.

High-strength and ductility bimodal-grained Al–Li/Al–Li–Zr composite produced by accumulative roll bonding

2019 ◽  
Vol 761 ◽  
pp. 138049 ◽  
Author(s):  
Yang Wang ◽  
Huajie Wu ◽  
Xiaoting Liu ◽  
Yunlei Jiao ◽  
Jianfeng Sun ◽  
...  
Keyword(s):  
Accumulative Roll Bonding ◽  
High Strength ◽  
Roll Bonding ◽  
Strength And Ductility
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