Annealing Characteristics of Nanostructured Cu-Fe-P Alloy Processed by Accumulative Roll-Bonding

2007 ◽  
Vol 7 (11) ◽  
pp. 3872-3875 ◽  
Author(s):  
Seong-Hee Lee ◽  
Chung-Hyo Lee ◽  
Suk-Ja Yoon ◽  
Seung-Zeon Han ◽  
Cha-Yong Lim
Keyword(s):  
High Purity ◽  
Accumulative Roll Bonding ◽  
Copper Alloy ◽  
Static Recrystallization ◽  
Roll Bonding ◽  
Ultrafine Grained ◽  
Coarse Grains ◽  
Annealed Copper ◽  
Purity Copper ◽  
Nanostructured Copper

Annealing characteristics of a nanostructured copper alloy processed by accumulative roll-bonding (ARB) were studied. A nano-grained Cu-Fe-P alloy processed by 8 cycles of the ARB was annealed at various temperatures ranging from 100 to 400 °C for 0.6 ks. The sample still showed an ultrafine grained (UFG) structure up to 250 °C, however above 300 °C it began to replace by equiaxed and coarse grains due to an occurrence of the conventional static recrystallization. The hardness of the annealed copper decreased largely above 300 °C. These annealing characteristics of the UFG copper alloy were compared to those of a high purity copper.

Effect of Working Temperature on Microstructure and Mechanical Properties of Ultrafine Grained Al and Al-5vol.%SiCp Composite Processed by Accumulative Roll-Bonding

2007 ◽  
Vol 534-536 ◽  
pp. 1381-1384
Author(s):  
Seong Hee Lee ◽  
Si Young Chang ◽  
Sung Tag Oh
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Accumulative Roll Bonding ◽  
Equivalent Strain ◽  
Roll Bonding ◽  
Working Temperature ◽  
Microstructure And Mechanical Properties ◽  
Ultrafine Grained ◽  
Coarse Grains ◽  
Almost All

The effect of working temperature on microstructure and mechanical properties of ultrafine grained monolithic Al and Al-5vol.%SiCp composite processed by accumulative roll bonding (ARB) was studied. The ARB was performed up to eight cycles (an equivalent strain of ~6.4) without lubricant. The working temperature was varied from ambient temperature to 200 C. The samples processed at temperatures below 100C exhibited an ultrafine grained structure over almost all regions. However, the samples processed at 200C showed an inhomogeneous structure in which a few coarse grains due to an occurrence of conventional recrystallization is partially seen. The tensile strength of both the monolithic Al and the composite decreased with increasing the ARB working temperature. The variation of microstructure and mechanical properties of the composite with the working temperature was compared to that of the monolithic aluminum.

Difference in Annealing Characteristics of Nanostructured Copper Alloys Processed by Accumulative Roll Bonding

2007 ◽  
Vol 124-126 ◽  
pp. 1373-1376
Author(s):  
Seong Hee Lee ◽  
Seung Zeon Han ◽  
Cha Yong Lim
Keyword(s):  
Mechanical Properties ◽  
Accumulative Roll Bonding ◽  
Copper Alloys ◽  
Coarse Grained ◽  
Roll Bonding ◽  
Annealing Temperatures ◽  
Microstructure And Mechanical Properties ◽  
Ultrafine Grained ◽  
The Difference ◽  
Nanostructured Copper

The difference in annealing characteristics of oxygen free copper (OFC) and deoxidized low-phosphorous copper (DLP) processed by ARB was studied. The copper alloys processed by eight cycles of the ARB were annealed for 10 minutes at various temperatures ranging from 100 to 400°C. The variation of microstructure and mechanical properties with annealing was significantly different in both copper alloys. In case of OFC, the ultrafine grained (UFG) structure formed by the ARB still remained up to 200°C, and above 200°C it was completely replaced with a coarse grained structure due to an occurrence of the conventional recrystallization. However, in case of DLP, the recrystallization did not occur even at 350°C. The strength of the OFC also decreased significantly at annealing temperatures above 200°C, while the hardness of the DLP did not decrease so largely up to 350°C. These differences in annealing characteristics in both copper alloys were discussed in terms of purity.

Annealing Characteristics of Nano-Grained Oxygen Free Copper Processed by Accumulative Roll-Bonding Process

2006 ◽  
Vol 6 (11) ◽  
pp. 3661-3664 ◽  
Author(s):  
Seong-Hee Lee ◽  
Chung Hyo Lee ◽  
Seung Zeon Han ◽  
Cha Yong Lim
Keyword(s):  
Tensile Strength ◽  
Accumulative Roll Bonding ◽  
Static Recrystallization ◽  
Pure Aluminum ◽  
Bonding Process ◽  
Accumulative Roll Bonding Process ◽  
Roll Bonding ◽  
Ultrafine Grains ◽  
Commercially Pure ◽  
Coarse Grains

Annealing characteristics of nano-grained oxygen free copper processed by accumulative roll-bonding (ARB) were studied. A nano-grained oxygen free copper fabricated by 8 cycles of the ARB was annealed at various temperatures ranging from 100 to 300 °C for 0.6 ks. TEM observation revealed that the ultrafine grains still sustained up to 150 °C, however above 200 °C they were replaced by equiaxed and coarse grains due to an occurrence of the static recrystallization. The tensile strength of the copper decreased largely above 200 °C. These annealing characteristics of the copper were compared with those of a commercially pure aluminum.

Effect of Strain Rate on Microstructural Evolution of Nano-Grained Copper in Accumulative Roll-Bonding Process

2008 ◽  
Vol 580-582 ◽  
pp. 71-74
Author(s):  
Seong Hee Lee ◽  
Sang Shik Kim ◽  
Seung Zeon Han ◽  
Cha Yong Lim
Keyword(s):  
Mechanical Properties ◽  
Strain Rate ◽  
Microstructural Evolution ◽  
High Purity ◽  
Accumulative Roll Bonding ◽  
Bonding Process ◽  
Strain Rates ◽  
Accumulative Roll Bonding Process ◽  
Roll Bonding ◽  
Purity Copper

The effects of strain rate in rolling on microstructures and mechanical properties of a nano-grained high purity copper processed by accumulative roll bonding (ARB) were studied. The rolling during ARB was conducted with two kinds of strain rates (2.6sec-1 and 37sec-1). The microstructural evolution of the copper with ARB proceeding was somewhat different in both methods. However, the variation of mechanical properties with ARB was very similar to each other.

Microstructural Evolution during Accumulative Roll-Bonding Process of a High Performance Copper Alloy

2011 ◽  
Vol 378-379 ◽  
pp. 597-600
Author(s):  
Seong Hee Lee ◽  
Daejin Yoon ◽  
Hiroshi Utsunomiya
Keyword(s):  
Microstructural Evolution ◽  
Accumulative Roll Bonding ◽  
Copper Alloy ◽  
High Performance ◽  
Rolling Direction ◽  
Bonding Process ◽  
Accumulative Roll Bonding Process ◽  
Small Aspect Ratio ◽  
Roll Bonding ◽  
Ultrafine Grained

Microstructural evolution of a copper alloy processed by accumulative roll-bonding (ARB) was investigated by EBSD analysis. The grains became thinner and elongated to the rolling direction with increasing the number of ARB cycles. The subdivision of the grains to the rolling direction actively begins to occur after 5 cycles of the ARB, resulting in formation of ultrafine grains with small aspect ratio. After 8 cycles, the ultrafine grained structure with the average grain diameter of 250nm developed in almost whole regions of the sample. In addition, the fraction of high-angle grain boundaries increased with the number of ARB cycles and reached about 0.7 after 8 cycles. The texture development of the ARB processed samples was different depending on the number of ARB cycles and the positions in the thickness.

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.

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