Corrosion behavior of ultrafine-grained copper processed by equal channel angular pressing in simulated sea water

2018 ◽  
Vol 69 (10) ◽  
pp. 1455-1461 ◽  
Author(s):  
Daoshuan Yang ◽  
Yuecheng Dong ◽  
Hui Chang ◽  
Igor Alexandrov ◽  
Feng Li ◽  
...  
Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 950 ◽  
Author(s):  
Zequn Yu ◽  
Yuecheng Dong ◽  
Xin Li ◽  
Jingzhe Niu ◽  
Igor Alexandrov ◽  
...  

The aim of this study was to investigate the corrosion resistance of ultrafine-grained (UFG) Ti-6Al-7Nb fabricated by equal channel angular pressing (ECAP) and coarse-grained (CG) Ti- 6Al- 7Nb. The microstructure of each specimen was investigated by the electron backscattered diffraction (EBSD) method. The corrosion behavior of each specimen was determined by electrochemical measurement in Ringer’s solution. The surface corroded morphologies and oxide film formed on Ti-6Al-7Nb alloy after electrochemical measurement were investigated by scanning electron microscope (SEM) and X-ray photoelectron spectroscopy (XPS). EBSD investigation shows that the grain size of UFG Ti-6Al-7Nb decreased to ~0.4 µm, accompanied by low angle grain boundaries (LAGBs) accounting for 39%. Potentiodynamic polarization and electrochemical impedance spectroscopy (EIS) results indicated that UFG Ti-6Al-7Nb alloy possessed a better corrosion resistance. The surface corroded morphologies revealed many small and shallow corrosion pits, which can be attributed to the good compactness of the oxide film and a rapid self- repairing ability of the UFG Ti-6Al-7Nb alloy.


2015 ◽  
Vol 1095 ◽  
pp. 942-946 ◽  
Author(s):  
Liu Yan Zhang ◽  
Ai Bin Ma ◽  
Jing Hua Jiang ◽  
Hui Shu Wu ◽  
Hai Bin Yu

A series of bulk ultrafine-grained (UFG) pure iron with grain size of 250-450 nm were fabricated by equal-channel angular pressing (ECAP) and annealing. Effects of ECAP passes on the corrosion behavior of the UFG pure iron were investigated. Results show that ECAP accelerates the acid corrosion rate of pure iron, but improves its anodic passivation property. The acid corrosion resistance of the UFG pure iron is restored through a large number of ECAP passes as well as through an annealing treatment. Annealing treatment is not good for the anodic passivation property of the UFG pure iron after a small number of ECAP passes. However, after a large number of ECAP passes (up to16), the corrosion resistance and anodic passivation property of UFG pure iron are less affected by annealing.


2008 ◽  
Vol 579 ◽  
pp. 29-40 ◽  
Author(s):  
Cheng Xu ◽  
Megumi Kawasaki ◽  
Roberto B. Figueiredo ◽  
Zhi Chao Duan ◽  
Terence G. Langdon

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.


2013 ◽  
Vol 803 ◽  
pp. 226-229
Author(s):  
Da Ran Fang ◽  
Chun Liu ◽  
Feng Fang Liu

Al-3.9wt.%Cu alloy was subjected to equal channel angular pressing (ECAP) and subsequent low temperature annealing treatment, and the corrosion resistance of the samples was investigated by potentiodynamic polarization measurements in 3.5% NaCl solution. The results show that the corrosion rate of the ultrafine-grained alloy increases, in comparison with the coarse-grained alloy. Meanwhile, it is noted that the corrosion resistance of the alloy subjected to ECAP can be improved by relief annealing.


2008 ◽  
Vol 43 (23-24) ◽  
pp. 7409-7417 ◽  
Author(s):  
Matthias Hockauf ◽  
Lothar W. Meyer ◽  
Daniela Nickel ◽  
Gert Alisch ◽  
Thomas Lampke ◽  
...  

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