Microstructure Development and Related Mechanical Behavior of the ZEW200 Mg Alloy Processed by Differential Speed Rolling and Equal Channel Angular Pressing

2018 ◽  
Vol 941 ◽  
pp. 931-936 ◽  
Author(s):  
José Victoria-Hernández ◽  
Gerrit Kurz ◽  
Joungsik Suh ◽  
Dietmar Letzig

The present work investigates the influence of shear deformation on microstructural-texture and mechanical behavior of ZEW200 Mg alloy sheets. For the introduction of extra shear deformation during thermomechanical processing, the separate effect of differential speed rolling (DSR) and equal channel angular pressing (ECAP) were analyzed. The results were compared with the microstructure and mechanical behavior of equal speed rolled (ESR) ZEW200 sheets. No significant texture changes were observed after the utilization of DSR, while ECAP processing was effective in changing the character of the texture and reducing the texture intensity. The large yield stress asymmetry observed in the rolled sheet is strongly reduced in the ECAP processed sheets. Results showed the potential to use shear deformation to modify the crystallographic texture via the profuse activation of {10-12}<10-11> extension twins. The presence of a large twin fraction of the microstructure modified the work hardening behavior of the processed sheets due to the further activation of basal <a> slip. The application of extra shear deformation to tailor the texture during processing is, therefore, an alternative to optimize the deformation behavior of already formable Mg alloys.

Metals ◽  
2020 ◽  
Vol 10 (5) ◽  
pp. 654
Author(s):  
Ryosuke Matsutani ◽  
Nobuo Nakada ◽  
Susumu Onaka

Ultra-fine-grained (UFG) Cu shows little total elongation in tensile tests because simple shear deformation is concentrated in narrow regions during the initial stage of plastic deformation. Here, we attempted to improve the total elongation of UFG Cu obtained by equal-channel angular pressing. By making shallow dents on the side surfaces of the plate-like specimens, this induced pure shear deformation and increased their total elongation. During the tensile tests, we observed the overall and local deformation of the dented and undented UFG Cu specimens. Using three-dimensional digital image correlation, we found that the dented specimens showed suppression of thickness reduction and delay in fracture by enhancement of pure shear deformation. However, the dented and undented specimens had the same ultimate tensile strength. These results provide us a new concept to increase total elongation of UFG materials.


2008 ◽  
Vol 23 (11) ◽  
pp. 3029-3039 ◽  
Author(s):  
Xinsheng Huang ◽  
Kazutaka Suzuki ◽  
Akira Watazu ◽  
Ichinori Shigematsu ◽  
Naobumi Saito

Differential speed rolling (DSR) has been carried out on AZ31 alloys with Mn additions of 0 to 0.6 wt% for investigating the effects of Mn on microstructure, texture, mechanical properties, and formability. The Al–Mn compounds were formed in the sample with a Mn addition of only 0.2 wt% because of its low solid-solubility limit. There were tiny differences among the DSR-processed AZ31 alloys with different Mn contents, while the AZ31 alloy without Mn addition exhibited a more homogeneous microstructure, a weaker basal texture intensity, and a much superior formability together with a larger likelihood of grain growth during annealing. The Mn dissolving in αMg matrix exerted a far stronger influence on the resulting properties compared with those existing in form of the Al–Mn compounds. The Mn solute atoms induced an increase in c/a ratio, which may suppress activity of nonbasal slips and in turn degrade the deformation capability.


2015 ◽  
Vol 1101 ◽  
pp. 93-98
Author(s):  
Yue Shen ◽  
Chuan Ting Ren ◽  
Guo Quan Zhang ◽  
Ming Xie ◽  
Ming Wen ◽  
...  

The shear deformation behavior of the course-grained Cu-8wt%Ag alloy processed by one pass of equal channel angular pressing (ECAP) was revealed through the metallurgical microscope and the scanning electron microscope. Through the macro-level and micro-level synthesis analysis, it is confirmed that there are two shear deformation during the ECAP processing: the one along the intersection plane (IP) and the other along the vertical plane to the IP. And it is estimated that theoretical ranges of two shear angles are-32°<θ1<0° and 43°<θ2<58° respectively. Finally, it is also proved that the evolution of the shear bands is affected by the parallel and vertical shear to the IP of the ECAP die, and that, besides the shear along the IP, the shear along the vertical plane to the IP also plays an important role during the plastic deformation.


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