Superplastic Behavior of As-Equal Channel Angular Pressed 5083 Al and 5083 Al-0.2 Sc Alloys

2005 ◽  
Vol 475-479 ◽  
pp. 2937-2940 ◽  
Author(s):  
Kyung Tae Park ◽  
Chong Soo Lee ◽  
Dong Hyuk Shin
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Al Alloy ◽  
Superplastic Behavior ◽  
Angular Pressing ◽  
Rate Region ◽  
Ultrafine Grained ◽  
Order Of Magnitude ◽  
5083 Al Alloy

An ultrafine grained structure was obtained in the two grades of a 5083 Al alloy with or without scandium by using equal channel angular pressing and its superplastic behavior was characterized. For the alloy without scandium, low temperature superplasticity was obtained but high strain rate superplasticity was unlikely to occur. By contrast, the alloy containing a small amount of scandium exhibited high strain rate superplasticity. It was found that, in both cases, the strain rate region showing superplasticity was very limited, i.e. one order of magnitude. From the mechanical data, the deformation mechanisms were examined.

High strain rate superplasticity of submicrometer grained 5083 Al alloy containing scandium fabricated by severe plastic deformation

2003 ◽  
Vol 341 (1-2) ◽  
pp. 273-281 ◽  
Author(s):  
Kyung-Tae Park ◽  
Duck-Young Hwang ◽  
Young-Kook Lee ◽  
Young-Kuk Kim ◽  
Dong Hyuk Shin
Keyword(s):  
Plastic Deformation ◽  
Severe Plastic Deformation ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Al Alloy ◽  
5083 Al Alloy

Superplastic Deformation of Ultrafine Grained Al Alloy Processed by ECAP and Post-Rolling

2006 ◽  
Vol 503-504 ◽  
pp. 119-124 ◽  
Author(s):  
Kyung Tae Park ◽  
Chong Soo Lee ◽  
Yong Suk Kim ◽  
Dong Hyuk Shin
Keyword(s):  
Cold Rolling ◽  
Strain Rate ◽  
High Strain ◽  
Grain Boundary Sliding ◽  
Strain Rate Range ◽  
Al Alloy ◽  
Superplastic Behavior ◽  
Ultrafine Grained ◽  
Boundary Sliding ◽  
Main Deformation

Superplastic behavior of an ultrafine grained (UFG) 5154 Al alloy processed by ECAP and cold rolling (ECAP+CR sample) was investigated and compared with that of the alloy processed by only ECAP without rolling (ECAP sample) in the strain rate range of 10-4~5×10-1 s-1 at 723 K. Processing of the ECAP+CR sample consisted of ECAP of 4 passes, which was less than that showing the optimum microstructure for high strain rate superplasticity of UFG Al alloys (i.e. 8 passes), with route Bc and subsequent cold rolling (70% thickness reduction). The superplastic elongation was remarkably enhanced by post-rolling. An analysis of the mechanical data revealed that deformation of the ECAP+CR sample was dominated by grain boundary sliding, but dislocation viscous glide was the main deformation mechanism for the ECAP sample. In addition, cavitation in the ECAP+CR sample was insignificant up to ∼300% elongation.

Superplastic Behavior in Ultrafine-Grained Materials Produced by Equal-Channel Angular Pressing

2008 ◽  
Vol 579 ◽  
pp. 29-40 ◽  
Author(s):  
Cheng Xu ◽  
Megumi Kawasaki ◽  
Roberto B. Figueiredo ◽  
Zhi Chao Duan ◽  
Terence G. Langdon
Keyword(s):  
Equal Channel Angular Pressing ◽  
High Strain ◽  
Processing Method ◽  
Strain Rates ◽  
Bulk Materials ◽  
Superplastic Behavior ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Ultrafine Grained Materials ◽  
Aluminum And Magnesium Alloys

Equal-channel angular pressing (ECAP) is a convenient processing method for refining the grain size of bulk materials to the submicrometer level. Metallic alloys processed by ECAP often exhibit excellent superplastic characteristics including superplasticity at high strain rates. This paper summarizes recent experiments designed to evaluate the occurrence of superplasticity in representative aluminum and magnesium alloys and in the Zn-22% Al eutectoid alloy.

High Strain Rate Superplasticity in a Zr and Sc Modified 7075 Aluminum Alloy Produced by ECAP

2008 ◽  
Vol 584-586 ◽  
pp. 164-169 ◽  
Author(s):  
Krystof Turba ◽  
Premysl Malek ◽  
Edgar F. Rauch ◽  
Miroslav Cieslar
Keyword(s):  
Aluminum Alloy ◽  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Rate Sensitivity ◽  
7075 Aluminum Alloy ◽  
Fine Grained ◽  
Angular Pressing ◽  
Average Grain Size ◽  
Elongation To Failure

Equal-channel angular pressing (ECAP) at 443 K was used to introduce an ultra-fine grained (UFG) microstructure to a Zr and Sc modified 7075 aluminum alloy. Using the methods of TEM and EBSD, an average grain size of 0.6 1m was recorded after the pressing. The UFG microstructure remained very stable up to the temperature of 723 K, where the material exhibited high strain rate superplasticity (HSRSP) with elongations to failure of 610 % and 410 % at initial strain rates of 6.4 x 10-2 s-1 and 1 x 10-1 s-1, respectively. A strain rate sensitivity parameter m in the vicinity of 0.45 was observed at temperatures as high as 773 K. At this temperature, the material still reached an elongation to failure of 430 % at 2 x 10-2 s-1. These results confirm the stabilizing effect of the Zr and Sc additions on the UFG microstructure in a 7XXX series aluminum alloy produced by severe plastic deformation.

Tensile Ductility of Ultra-Fine Grained Copper at High Strain Rate

2010 ◽  
Vol 160-162 ◽  
pp. 260-266 ◽  
Author(s):  
Tao Suo ◽  
Kui Xie ◽  
Yu Long Li ◽  
Feng Zhao ◽  
Qiong Deng
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Testing Machine ◽  
Coarse Grained ◽  
Dislocation Dynamic ◽  
Pressing Method ◽  
Fine Grained ◽  
Angular Pressing ◽  
Split Hopkinson

In this paper, ultra-fine grained copper fabricated by equal channel angular pressing method and annealed coarse grained copper were tensioned under both quasi-static and dynamic loading conditions using an electronic universal testing machine and the split Hopkinson tension bar respectively. The rapture surface of specimen was also observed via a Scanning Electron Microscope (SEM). The experimental results show that the ductility of polycrystalline copper decreases remarkably due to the grain refinement. However, with the increase of applied strain rate, ductility of the UFG-Cu is enhanced. The fracture morphologies also give the evidence of enhanced ductility of UFG-Cu at high strain rate. It is believed the enhanced ductility of UFG materials at high strain rate can be attributed to the restrained dislocation dynamic recovery.

Application of High-Strain-Rate Superplastic Zn-Al Alloy to Seismic Dampers and its Optimised Shape Design

2007 ◽  
pp. 583-590
Author(s):  
Atsumichi Kushibe ◽  
Yorinobu Takigawa ◽  
Kenji Higashi ◽  
Kazuo Aoki ◽  
Koichi Makii ◽  
...  
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Shape Design ◽  
Al Alloy

Application to Seismic Dampers in High-Strain-Rate Superplastic Zn-Al Alloy

2005 ◽  
pp. 3055-3060
Author(s):  
Atsumichi Kushibe ◽  
Koichi Makii ◽  
L.F. Chiang ◽  
Tsutomu Tanaka ◽  
Masahide Kohzu ◽  
...  
Keyword(s):  
High Strain Rate ◽  
Strain Rate ◽  
High Strain ◽  
Al Alloy
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