Structure and Mechanical Properties of Severely Deformed Cu-Cr-Zr Alloys Produced by Accumulative Roll-Bonding Process

2008 ◽  
Vol 584-586 ◽  
pp. 791-796 ◽  
Author(s):  
Kazuo Kitagawa ◽  
T. Akita ◽  
K. Kita ◽  
Masahide Gotoh ◽  
Naoki Takata ◽  
...  

Aging behavior and mechanical properties of ultra fine grained Cu-Cr-Zr alloy sheet produced by accumulative roll bonding (ARB) process were investigated. A Cu-0.85Cr-0.07Zr (in mass%) alloy was solution treated and then cold-rolled at ambient temperature in the sheet of 1 mm thick. The sheets were heavily deformed by ARB process at ambient temperature up to 5 cycles. The grain size was reduced down to 210 nm and the fraction of high angle grain boundaries (HAGB’s) in the specimen after ARB process was 63%. The proof stress ( σ 0.2) and elongation were 540 MPa and 10%, respectively. Due to the aging treatment, a little grain growth took place (240 nm) and the fraction of HAGB’s was increased to 67%. The proof stress and elongation of the aged one increased to 605 MPa and 15%, respectively. It was noteworthy that the electrical conductivity remarkably increased from 35% to 79%IACS by the aging treatment. It was concluded that the aging treatment after ARB process enhanced not only the mechanical properties but also the electrical conductivity in the Cu-Cr-Zr alloys.

2014 ◽  
Vol 59 (1) ◽  
pp. 127-131 ◽  
Author(s):  
J. Bogucka

Abstract The influence of bonding temperature on microstructure and mechanical properties of AA5251 alloy sheets have been analyzed in the paper. The alloy was deformed with the method of accumulative roll bonding (ARB) in various temperature conditions i.e. at ambient temperature up to 5th cycle (ε = 4.0) and using pre-heating of sheet packs at 200°C and 300°C up to 10 cycles (ε = 8.0). The deformed material was subjected to structural observations using TEM, measurements of crystallographic texture with the technique of X-ray diffraction and tensile tests. It was established that the temperature of roll-bonding had a significant effect on the structure evolution and the observed changes of mechanical properties. High refinement of microstructure and optimum mechanical properties were obtained for the material processed at lower temperatures, i.e. at ambient temperature and pre-heating at 200°C. Recovery structure processes occurring during deformation were observed in the alloy bonded with pre-heating at 300°C and therefore mechanical properties were lower than for the alloy bonded at lower temperatures.


2015 ◽  
Vol 60 (2) ◽  
pp. 1195-1198 ◽  
Author(s):  
S.-H. Lee ◽  
S.R. Lee

Abstract A multi-layered complex aluminum alloy was successfully fabricated by three-layer stack accumulative roll bonding(ARB) process. The ARB using AA1050 and AA5052 alloy sheets was performed up to 7 cycles at ambient temperature without lubrication. The specimen processed by the ARB showed a multi-layer aluminum alloy sheet in which two aluminum alloys are alternately stacked. The grain size of the specimen decreased with the number of ARB cycles, became about 350nm in diameter after 7cycles. The tensile strength increased with the number of ARB cycles, after 6c it reached 281MPa which is about twice higher than that of the starting material. The microstructures and mechanical properties of a three-layer AA1050/AA5052 alloy fabricated by the ARB were compared to those of the conventional ARB-processed material.


2008 ◽  
Vol 22 (18n19) ◽  
pp. 2848-2857 ◽  
Author(s):  
A. KAZEMI TALACHI ◽  
M. EIZADJOU ◽  
H. DANESH MANESH ◽  
K. JANGHORBAN

Ultra-fine grained 1100 Al alloy was successfully produced by accumulative roll bonding (ARB) process. TEM investigation and SAD patterns showed that, after eight cycles of ARB, sheets were found to contain ultra-fine grains with high angle grain boundaries. The mechanical properties of the ARB processed (ARBed) 1100 aluminum alloy increased with increasing the number of ARB cycles. The elongation dropped abruptly at the first cycles. Wear properties were investigated using a pin on disk wear machine at ambient environment. Contrary to an expectation, the wear resistance of the ARBed Al alloy was less than the non-processed Al alloy. Morphologies of worn surfaces were studied by scanning electron microscope (SEM).


2014 ◽  
Vol 794-796 ◽  
pp. 851-856
Author(s):  
Tadashiege Nagae ◽  
Nobuhiro Tsuji ◽  
Daisuke Terada

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.


Materials ◽  
2021 ◽  
Vol 14 (15) ◽  
pp. 4200
Author(s):  
Zhigang Li ◽  
Hao Jiang ◽  
Minghui Wang ◽  
Hongjie Jia ◽  
Hongjiang Han ◽  
...  

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.


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