Corrosion and Mechanical Behaviors of Cu-35%Zn Alloy Prepared by Equal Channel Angular Pressing (ECAP)

2006 ◽  
Vol 503-504 ◽  
pp. 823-828 ◽  
Author(s):  
Y. Choi ◽  
Nam Ihn Cho ◽  
Hyoung Seop Kim ◽  
Sun Ig Hong
Keyword(s):  
Shear Band ◽  
Equal Channel Angular Pressing ◽  
Corrosion Potential ◽  
H2so4 Solution ◽  
Mechanical Behaviors ◽  
Ecap Pass ◽  
Angular Pressing ◽  
Feed Direction ◽  
Zn Alloy ◽  
Zn Alloys

Effect of equal-channel angular pressing (ECAP) on the corrosion and mechanical properties of Cu-35%Zn alloy were studied. Two types of feed direction were selected. One is parallel pass and the other is 180°degree rotated ECAP pass after each pass. Both ECAP passes made texture in each specimen in which shear band with 45 degree on transverse direction and twins exist. The specimen prepared by parallel ECAP pass has finer shear band. Relative amount of twins to shear band on the microstructure becomes decrease with number of ECAP pass. Microhardness increased from 75 Hv to 210 Hv by ECAP. The corrosion potential and rate of the ECAPed Cu-35%Zn alloys in aerated aqueous 1 M-H2SO4 solution were –92.3 mVSHE and 3.72x10-2 A/cm2 for route- A and –38.6 mVSHE and 5.08x10-2 A/cm2 for route-C, respectively. The corrosion potential and rate of depended on the feed direction and number of pass.

scholarly journals Effect of Equal-Channel Angular Pressing on Pitting Corrosion of Pure Aluminum

2012 ◽  
Vol 2012 ◽  
pp. 1-9 ◽  
Author(s):  
Injoon Son ◽  
Hiroaki Nakano ◽  
Satoshi Oue ◽  
Shigeo Kobayashi ◽  
Hisaaki Fukushima ◽  
...  
Keyword(s):  
Equal Channel Angular Pressing ◽  
Pitting Corrosion ◽  
Corrosion Potential ◽  
Pure Aluminum ◽  
Electrochemical Techniques ◽  
Oxide Films ◽  
Angular Pressing ◽  
Ecap Process ◽  
Pitting Corrosion Resistance ◽  
Al Oxide

The effect of equal-channel angular pressing (ECAP) on the pitting corrosion of pure Al was investigated using electrochemical techniques in solutions containing 0.1 m mol·dm−3of Na2SO4and 8.46 mol·dm−3of NaCl (300 ppm Cl−) and followed by surface analysis. The potential for pitting corrosion of pure Al was clearly shifted in the noble direction by the ECAP process indicating that this process improves resistance to pitting corrosion. The time dependence of corrosion potential and the anodic potential at 1 A·m−2revealed that the rate of formation of Al oxide films increased due to a decrease in the grain size of the Al after ECAP. Since there exists a negligible amount of impurity precipitates in pure Al, the improvement in pitting corrosion resistance of pure Al by ECAP appears to be attributable to an increase in the rate of formation of Al oxide films.

scholarly journals Mechanical Properties and Microstructure Evolution of Mg-6 wt % Zn Alloy during Equal-Channel Angular Pressing

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 841 ◽  
Author(s):  
Jingli Yan ◽  
Zijun Qin ◽  
Kai Yan
Keyword(s):  
Electron Microscopy ◽  
Mechanical Properties ◽  
Grain Refinement ◽  
Equal Channel Angular Pressing ◽  
Testing Machine ◽  
Grain Structure ◽  
X Ray Diffraction ◽  
Angular Pressing ◽  
Transmission Electron ◽  
Zn Alloy

Equal-channel angular pressing (ECAP) was performed on a Mg (6 wt %) Zn alloy at temperatures from 160 to 240 °C and the microstructures and mechanical properties were studied using optical microscopy, X-ray diffraction, scanning electron microscopy, transmission electron microscopy, and an electronic universal testing machine. The results showed that ECAP was effective for grain refinement and a bi-modal grain structure formed at low temperatures, which was stable during ECAP from 160 to 200 °C. MgZn2 phase and Mg4Zn7 phase were generated during the ECAP process. The mechanical properties remarkably increased after two repetitions of ECAP. However, the strengths could not be further improved by increasing the plastic deformation, but decreased when ECAP was performed between 200 and 240 °C. The mechanical properties of the ECAP Mg-6Zn alloy was determined by a combination of grain refinement strengthening, precipitation hardening, and texture softening.

Effect of Hot Rolling and Equal-Channel Angular Pressing on Generation of Globular Microstructure in Semi-Solid Mg-3%Zn Alloy

2014 ◽  
Vol 217-218 ◽  
pp. 381-388 ◽  
Author(s):  
Łukasz Rogal ◽  
Frank Czerwiński ◽  
Lidia Litynska-Dobrzyńska ◽  
Piotr Bobrowski ◽  
Anna Wierzbica-Miernik ◽  
...  
Keyword(s):  
Equal Channel Angular Pressing ◽  
Hot Rolling ◽  
Cast Alloy ◽  
Single Step ◽  
Deformation Bands ◽  
Angular Pressing ◽  
Globule Size ◽  
Alloy Microstructure ◽  
Hot Rolled ◽  
Zn Alloy

A combination of hot rolling and equal channel angular pressing (ECAP) was explored to generate globular microstructures in the Mg-3%Zn alloy after re-heating to the semisolid state. It was found that the single-step deformation of as-cast alloy via hot rolling at 350°C with a thickness reduction of 50% refined the alloy microstructure by creating deformation bands of the Mg (α) phase with a size of the order of tenths of micrometers. After re-heating to 630 °C, the microstructure transformed into spheroidal morphologies with an average globule size of 82 μm. An additional deformation of the hot-rolled alloy by the ECAP method at 250 °C further refined the alloy microstructure to sub-micrometer grains of lath and equiaxed shapes. After re-heating of this microstructure to 630 °C the average globule size reached 62 μm, which is roughly 25% smaller than that achieved for the hot-rolled precursor. The role of strain-induced melt activation (SIMA) techniques in generation of globular morphologies in Mg-based alloys after partial re-melting is discussed.

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