Microstructure and Corrosion Behaviour of Ultrafine-Grained Copper

2006 ◽  
Vol 503-504 ◽  
pp. 883-888 ◽  
Author(s):  
Branislav Hadzima ◽  
Miloš Janeček ◽  
Ralph Jörg Hellmig ◽  
Yulia Kutnyakova ◽  
Yuri Estrin
Keyword(s):  
Microstructure Evolution ◽  
Current Density ◽  
Corrosion Behaviour ◽  
Corrosion Damage ◽  
Corrosion Current ◽  
Good News ◽  
Coarse Grained ◽  
Anodic Current Density ◽  
Angular Pressing ◽  
Ultrafine Grained

Microstructure evolution and corrosion behaviour of ultrafine-grained copper processed by equal channel angular pressing (route Bc) were studied. The results of TEM investigation of the microstructure evolution are presented along with the measurements of the corrosion potential, the corrosion current density and the anodic current density for two aggressive media, viz. 3% NaCl and 1M H2SO4. An important finding and a good news is that the corrosion behaviour of ECAP copper is not inferior to and does not qualitatively differ from that of the coarse grained material. Moreover, it was shown by SEM investigation that the corrosion damage is more homogeneous in ultrafine grained ECAP processed copper than in its coarse grained counterpart.

scholarly journals Corrosion Resistance of Ultrafine-grained Titanium Alloys in Different Corrosive Environments

2020 ◽  
Vol 321 ◽  
pp. 06001
Author(s):  
Yuecheng Dong ◽  
Xin Li ◽  
Zequn Yu ◽  
Igor Alexandrov ◽  
Hui Chang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Titanium Alloys ◽  
Corrosion Current Density ◽  
Corrosion Current ◽  
Coarse Grained ◽  
Corrosive Environment ◽  
Ringer’S Solution ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Corrosive Environments

Corrosion Resistance of ultrafine-grained (UFG) titanium alloys fabricated by equal channel angular pressing (ECAP) was investigated in this study. Electrochemical measurements of pure Ti and Ti-6Al-7Nb alloy were conducted in 3.5 wt.% NaCl and Ringer’s solution separately. Results indicated that both ultrafine-grained pure Ti and Ti-6Al-7Nb alloy had much lower corrosion current density than annealed coarse-grained counterparts in the specified corrosive environment.

Corrosion Characteristics of an Ultrafine-Grained Al-Mg-Si Alloy (AA6082)

2008 ◽  
Vol 584-586 ◽  
pp. 988-993 ◽  
Author(s):  
Bernhard Wielage ◽  
Daniela Nickel ◽  
Thomas Lampke ◽  
Gert Alisch ◽  
Harry Podlesak ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Grain Boundaries ◽  
Electrochemical Impedance ◽  
Corrosion Behaviour ◽  
Coarse Grained ◽  
Angular Pressing ◽  
Transmission Electron ◽  
Ultrafine Grained ◽  
Before And After ◽  
Eis Measurements

The corrosion behaviour of the aluminium alloy, AA6082, processed by equal-channel angular pressing (ECAP) after different passes (route E, room temperature) was studied in comparison to the coarse-grained counterpart. The results of the electrochemical investigations (cyclovoltammetry; electrochemical impedance spectroscopy, EIS) are presented in correlation with the microstructure before and after the corrosion examinations. Both, chemical (precipitations, phases) and physical (dislocations, high-angle grain boundaries, grain size, low-angle grain boundaries) inhomogeneities characterize the microstructure of this commercially used Al-Mg-Si alloy. Results indicate an improved resistance against pitting of the ECAP material expressed by a reduced pitting density of up to 50 % and lower pit depths. EIS measurements and microstructural examinations (scanning electron microscopy, transmission electron microscopy, 3D topography measurement) confirm that ECAP modifies the number, size and distribution of these inhomogeneities, which leads to a more favourable corrosion behaviour.

Effect of Equal Channel Angular Pressing and Annealing on Corrosion Resistance of Al-Cu Alloy

2013 ◽  
Vol 803 ◽  
pp. 226-229
Author(s):  
Da Ran Fang ◽  
Chun Liu ◽  
Feng Fang Liu
Keyword(s):  
Corrosion Resistance ◽  
Low Temperature ◽  
Equal Channel Angular Pressing ◽  
Annealing Treatment ◽  
Coarse Grained ◽  
Nacl Solution ◽  
Angular Pressing ◽  
Cu Alloy ◽  
Low Temperature Annealing ◽  
Ultrafine Grained

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.

scholarly journals Evaluation of Electrochemical Treatment of Chloride Contaminated Mortar Containing GGBS

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Ki Hong Lee ◽  
Young Hee Jung ◽  
Jun Pil Hwang ◽  
Jong Sung Sim
Keyword(s):  
Current Density ◽  
Corrosion Behaviour ◽  
Chloride Concentration ◽  
Corrosion Damage ◽  
Electrochemical Treatment ◽  
Open Circuit ◽  
Galvanic Current ◽  
Treatment Conditions ◽  
Binder Type ◽  
Superior Corrosion Resistance

The present study concerns the influence of cementitious binder on electrochemical treatment of steel embedded in salt contaminated mortar. As binder, ordinary Portland cement (OPC) and ground granulated blast furnace slag (GGBS) were used and the current density of 250–750 mA/m2 was applied for 4 weeks to complete electrochemical chloride extraction. To evaluate the effect of electrochemical treatment the chloride profile and corrosion behaviour covering chloride concentration, galvanic current density, linear polarization resistance, open circuit potential, and mass loss were measured. An increase in the applied direct current density resulted in a decrease in the chloride concentration at the vicinity of steel, accompanying the mitigated corrosion damage. The performance of electrochemical treatment was more remarkable in mortar containing GGBS presumably due to binding mechanism. However, corrosion damage was more detrimental in GGBS rather than OPC at a given potential, while GGBS had superior corrosion resistance to a corrosive environment and treatment conditions. Therefore, the electrochemical treatment should be conducted prudently to evaluate the corrosion state of embedded steel depending on binder type.

Mechanical properties and corrosion behaviour of ultrafine-grained AA6082 produced by equal-channel angular pressing

2008 ◽  
Vol 43 (23-24) ◽  
pp. 7409-7417 ◽  
Author(s):  
Matthias Hockauf ◽  
Lothar W. Meyer ◽  
Daniela Nickel ◽  
Gert Alisch ◽  
Thomas Lampke ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Equal Channel Angular Pressing ◽  
Corrosion Behaviour ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Mechanical Properties And Corrosion

Structuration of Refractory Metals Tantalum and Niobium Using Modified Equal Channel Angular Pressing Technique

2019 ◽  
Vol 799 ◽  
pp. 103-108 ◽  
Author(s):  
Lembit Kommel ◽  
Babak Shahreza Omranpour ◽  
Valdek Mikli
Keyword(s):  
Equal Channel Angular Pressing ◽  
Coarse Grained ◽  
Uniaxial Tensile ◽  
Modified Technique ◽  
Uniaxial Tensile Strength ◽  
Large Samples ◽  
Angular Pressing ◽  
Ultrafine Grained ◽  
Von Mises ◽  
Ultrafine Grained Microstructure

In the present work, we use a modified Equal Channel Angular Pressing technique for structure and properties change of Tantalum and Niobium at room temperature. The main advantage of this modified technique is the possibility to produce relatively large samples with ultrafine-grained microstructure in all volume of the workpiece by reduced deformation load up to 25% via friction decrease, and also to prevent the punch fracture under high compression stress during pressing. The various microstructures and properties were produced in metals by using different von Mises strain levels up to ƐvM = 13.8. The changes in microstructure were studied by using SEM and TEM techniques. The change of mechanical properties was measured by using various tension and hardness testing setups. We can conclude that during processing the ultrafine-grained microstructure in as-cast Nb and Ta was formed. The uniaxial tensile strength, Vickers hardness, and plasticity of Nb and Ta significantly increased as compared to coarse-grained counterparts. We believe that the relatively large workpieces of pure bulk Ta and Nb metals with improved microstructure and exploitation properties are suitable materials for the modern industry.

scholarly journals Study on Corrosion Behavior of Ultrafine-Grained Ti-6Al-7Nb Fabricated by Equal Channel Angular Pressing

Metals ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 950 ◽  
Author(s):  
Zequn Yu ◽  
Yuecheng Dong ◽  
Xin Li ◽  
Jingzhe Niu ◽  
Igor Alexandrov ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Oxide Film ◽  
Equal Channel Angular Pressing ◽  
Corrosion Behavior ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Electrochemical Measurement ◽  
Coarse Grained ◽  
Angular Pressing ◽  
Ultrafine Grained

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.

Enhanced mechanical properties in ultrafine grained 7075 Al alloy

2005 ◽  
Vol 20 (2) ◽  
pp. 288-291 ◽  
Author(s):  
Y.H. Zhao ◽  
X.Z. Liao ◽  
Y.T. Zhu ◽  
R.Z. Valiev
Keyword(s):  
Mechanical Properties ◽  
Natural Aging ◽  
Al Alloys ◽  
Coarse Grained ◽  
Tensile Yield Strength ◽  
Al Alloy ◽  
Aged Sample ◽  
Angular Pressing ◽  
7075 Al Alloy ◽  
Ultrafine Grained

Highest strength for 7075 Al alloy was obtained by combining the equal-channel-angular pressing (ECAP) and natural aging processes. The tensile yield strength and ultimate strength of the ECAP processed and naturally aged sample were 103% and 35% higher, respectively, than those of the coarse-grained 7075 Al alloy counterpart. The enhanced strength resulted from high densities of Guinier–Preston (G-P) zones and dislocations. This study shows that severe plastic deformation has the potential to significantly enhance the mechanical properties of precipitate hardening 7000 series Al alloys.

Sign in / Sign up

Export Citation Format

Share Document