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H. M. Ghasemi - One of the best experts on this subject based on the ideXlab platform.

  • Erosion and erosion–corrosion of Al-Brass Alloy: Effects of jet velocity, sand concentration and impingement angle on surface roughness
    Transactions of Nonferrous Metals Society of China, 2017
    Co-Authors: Masih Abedini, H. M. Ghasemi
    Abstract:

    Abstract Effects of jet velocity, sand concentration and impingement angle on the surface roughness of Al-Brass Alloy were investigated after erosion and erosion–corrosion tests. The tests were performed using a jet impingement rig. The eroded surfaces were characterized using 2-D and 3-D surface profilometery and scanning electron microscopy (SEM). The results showed that there was an increase in the surface roughness of the erosion–corrosion samples as sand concentration was increased to 1, 5 and 10 g/L at jet velocities of 9, 6 and 3 m/s, respectively. However, the surface roughness decreased with a further increase in sand concentration. This decrease in the surface roughness was attributed to the higher work hardening of the surface, rebounding or blanketing effect and very high frequency of the impacts at the higher sand concentrations. The surface roughness increased as the jet velocity increased. The results also showed that the change in the surface roughness with impingement angle was not significant at two jet velocities of 3 and 6 m/s. However, at a higher jet velocity of 9 m/s, formation of ripples on the erosion surfaces at oblique angles resulted in a higher surface roughness as compared with the normal impingement angle.

  • Corrosion behavior of Al-Brass Alloy during erosion–corrosion process: Effects of jet velocity and sand concentration
    Materials and Corrosion-werkstoffe Und Korrosion, 2015
    Co-Authors: Masih Abedini, H. M. Ghasemi
    Abstract:

    Polarization and electrochemical impedance spectrometry measurements were performed on Al-Brass Alloy during the erosion–corrosion process. The erosion–corrosion tests were conducted at various SiO2 particle concentrations between 0–90 g/L and three jet velocities of 3, 6, and 9 m/s under an impingement angle of 90°. At a jet velocity of 3 m/s, the results showed a decrease in the corrosion rate at sand concentrations higher than 20 g/L, which was attributed to the particle rebounding effect. At higher jet velocities of 6 and 9 m/s, a continuous increase in the corrosion rate was observed with sand concentration. The results also showed a higher effect of jet velocity on the corrosion rate as compared with the sand concentration. This was related to the increase in the frequency and energy of the impacts by increase in jet velocity, whereas sand concentration could only affect the impact frequency. The role of impact energy on the corrosion rate was determined by calculation of normalized erosion-enhanced corrosion rate. At high sand concentrations, the normalized erosion-enhanced corrosion rate of the Alloy was a function of second power of jet velocity as was expected by an equation drove from the energy and frequency of impacts.

  • synergistic erosion corrosion behavior of al Brass Alloy at various impingement angles
    Wear, 2014
    Co-Authors: M. Abedini, H. M. Ghasemi
    Abstract:

    Abstract Erosion and erosion–corrosion behaviors of the Al–Brass Alloy were investigated using a slurry impingement rig at a velocity of 6 m/s under impingement angles ranging from 20° to 90°. The maximum erosion and erosion–corrosion rates occurred at an impingement angle of 40°. The results showed positive synergisms at all impingement angles. The rate of erosion enhanced by corrosion showed values up to 54% of the total erosion–corrosion rate. Polarization curves showed a passive behavior in the stagnant condition. No passivation was observed in the flow and erosion–corrosion conditions indicating low durability of protective layers on the Al–Brass Alloy at jet velocity of 6 m/s.

  • Synergistic erosion–corrosion behavior of Al–Brass Alloy at various impingement angles
    Wear, 2014
    Co-Authors: M. Abedini, H. M. Ghasemi
    Abstract:

    Abstract Erosion and erosion–corrosion behaviors of the Al–Brass Alloy were investigated using a slurry impingement rig at a velocity of 6 m/s under impingement angles ranging from 20° to 90°. The maximum erosion and erosion–corrosion rates occurred at an impingement angle of 40°. The results showed positive synergisms at all impingement angles. The rate of erosion enhanced by corrosion showed values up to 54% of the total erosion–corrosion rate. Polarization curves showed a passive behavior in the stagnant condition. No passivation was observed in the flow and erosion–corrosion conditions indicating low durability of protective layers on the Al–Brass Alloy at jet velocity of 6 m/s.

Martin F X Wagner - One of the best experts on this subject based on the ideXlab platform.

  • on the correlation of shear band formation and texture evolution in α Brass during accumulative roll bonding
    Scripta Materialia, 2018
    Co-Authors: Marcus Bohme, Martin F X Wagner
    Abstract:

    Abstract We studied the microstructural evolution of the low stacking fault energy α-Brass Alloy CuZn15 during accumulative roll bonding (ARB). Most notably, the typical Brass-type texture was clearly observed after four ARB passes (approx. 93.8% total thickness reduction), before significant shear localization set in. This observation contradicts the widely accepted idea that shear band formation is a necessary prerequisite for the development of the Brass type texture, indicating that the two phenomena, shear banding and development of the Brass texture, are only correlated in ARB, and that their order of appearance can be switched depending on experimental parameters.

  • On the correlation of shear band formation and texture evolution in $\alpha$-Brass during accumulative roll bonding
    arXiv: Materials Science, 2018
    Co-Authors: Marcus Bohme, Martin F X Wagner
    Abstract:

    We studied the microstructural evolution of the low stacking fault energy $\alpha$-Brass Alloy CuZn15 during accumulative roll bonding (ARB). Most notably, the typical Brass-type texture was clearly observed after four ARB passes (approx. 93.8 % total thickness reduction), before significant shear localization set in. This observation contradicts the widely accepted idea that shear band formation is a necessary prerequisite for the development of the Brass type texture, indicating that the two phenomena, shear banding and development of the Brass texture, are only correlated in ARB, and that their order of appearance can be switched depending on experimental parameters.

Marcus Bohme - One of the best experts on this subject based on the ideXlab platform.

  • on the correlation of shear band formation and texture evolution in α Brass during accumulative roll bonding
    Scripta Materialia, 2018
    Co-Authors: Marcus Bohme, Martin F X Wagner
    Abstract:

    Abstract We studied the microstructural evolution of the low stacking fault energy α-Brass Alloy CuZn15 during accumulative roll bonding (ARB). Most notably, the typical Brass-type texture was clearly observed after four ARB passes (approx. 93.8% total thickness reduction), before significant shear localization set in. This observation contradicts the widely accepted idea that shear band formation is a necessary prerequisite for the development of the Brass type texture, indicating that the two phenomena, shear banding and development of the Brass texture, are only correlated in ARB, and that their order of appearance can be switched depending on experimental parameters.

  • On the correlation of shear band formation and texture evolution in $\alpha$-Brass during accumulative roll bonding
    arXiv: Materials Science, 2018
    Co-Authors: Marcus Bohme, Martin F X Wagner
    Abstract:

    We studied the microstructural evolution of the low stacking fault energy $\alpha$-Brass Alloy CuZn15 during accumulative roll bonding (ARB). Most notably, the typical Brass-type texture was clearly observed after four ARB passes (approx. 93.8 % total thickness reduction), before significant shear localization set in. This observation contradicts the widely accepted idea that shear band formation is a necessary prerequisite for the development of the Brass type texture, indicating that the two phenomena, shear banding and development of the Brass texture, are only correlated in ARB, and that their order of appearance can be switched depending on experimental parameters.

M. Abedini - One of the best experts on this subject based on the ideXlab platform.

  • synergistic erosion corrosion behavior of al Brass Alloy at various impingement angles
    Wear, 2014
    Co-Authors: M. Abedini, H. M. Ghasemi
    Abstract:

    Abstract Erosion and erosion–corrosion behaviors of the Al–Brass Alloy were investigated using a slurry impingement rig at a velocity of 6 m/s under impingement angles ranging from 20° to 90°. The maximum erosion and erosion–corrosion rates occurred at an impingement angle of 40°. The results showed positive synergisms at all impingement angles. The rate of erosion enhanced by corrosion showed values up to 54% of the total erosion–corrosion rate. Polarization curves showed a passive behavior in the stagnant condition. No passivation was observed in the flow and erosion–corrosion conditions indicating low durability of protective layers on the Al–Brass Alloy at jet velocity of 6 m/s.

  • Synergistic erosion–corrosion behavior of Al–Brass Alloy at various impingement angles
    Wear, 2014
    Co-Authors: M. Abedini, H. M. Ghasemi
    Abstract:

    Abstract Erosion and erosion–corrosion behaviors of the Al–Brass Alloy were investigated using a slurry impingement rig at a velocity of 6 m/s under impingement angles ranging from 20° to 90°. The maximum erosion and erosion–corrosion rates occurred at an impingement angle of 40°. The results showed positive synergisms at all impingement angles. The rate of erosion enhanced by corrosion showed values up to 54% of the total erosion–corrosion rate. Polarization curves showed a passive behavior in the stagnant condition. No passivation was observed in the flow and erosion–corrosion conditions indicating low durability of protective layers on the Al–Brass Alloy at jet velocity of 6 m/s.

Ali Davoodi - One of the best experts on this subject based on the ideXlab platform.

  • Evaluation of corrosion resistance of polypyrrole/functionalized multi-walled carbon nanotubes composite coatings on 60Cu–40Zn Brass Alloy
    Progress in Organic Coatings, 2015
    Co-Authors: Ali Davoodi, Saleheh Honarbakhsh, Gholamali Farzi
    Abstract:

    Abstract Polypyrrole/multi-walled carbon nanotubes (PPy/MWCNT) and its carboxylic functionalized (PPy/MWCNT-COO − ) composite films were successfully electropolymerized by cyclic voltammetry as protective coating against corrosion on 60Cu–40Zn Brass Alloy surface. It yielded to strongly adherent and smooth nanocomposite films. Kinetics of the corrosion protection was investigated in 3.5 wt% NaCl solutions by electrochemical impedance spectroscopy (EIS) and potentiodynamic polarization tests. The results showed that the presence of MWCNT in PPy coat considerably reduces the corrosion rate of 60Cu–40Zn Brass Alloy. The enhanced inhibition is most likely due to interaction between MWCNT and PPy. This in turn, improves the Alloy passivation improvement and alters the permselectivity of the coating from anionic selectivity to the cationic selectivity. Moreover, PPy/MWCNT-COO − functionalized nanocomposite provided higher corrosion resistance coating than PPy/MWCNT alone.

  • Microstructural and mechanical properties of friction stir welded Cu–30Zn Brass Alloy at various feed speeds: Influence of stir bands
    Science & Engineering Faculty, 2011
    Co-Authors: Madjid Sarvghad Moghaddam, Reza Parvizi, M. Haddad-sabzevar, Ali Davoodi
    Abstract:

    In this study, the effect of various feed speeds on microstructure and mechanical properties of friction stir welded Cu–30Zn Brass Alloy is investigated. Rotation speed was fixed at 950rpm and feed speed varied in the range of 190–375mm/min. Examination of the microstructure showed very fine grains with some deformed grains in the stirred zone and some coarser grains in the thermo-mechanically affected zone and base metal. A unique deformation pattern, namely “stir band” in the stirred zone region was identified and its density increased by increase in feed speed. Results showed that the grain size profile was independent of feed speed and the hardness values decreased by increase in feed speed. Increase in feed speed led to a slight improvement of yield strength and ultimate tensile strength, associated to continuous spring-like morphology of stir bands acting as a strengthening structure. However, ductility reduces considerably from 57 to 27%. Moreover, it is observed that during tensile test, fracture cracks originate exactly adjacent to the stir bands.