scholarly journals Microstructure and Corrosion Behavior of Ni-Alloy/CrN Nanolayered Coatings

2011 ◽  
Vol 2011 ◽  
pp. 1-6 ◽  
Author(s):  
Hao-Hsiang Huang ◽  
Fan-Bean Wu ◽  
Jyh-Wei Lee ◽  
Li-Chun Chang
Keyword(s):  
Corrosion Behavior ◽  
Single Layer ◽  
Phase Identification ◽  
Bilayer Thickness ◽  
Ni Alloy ◽  
Nitride Coatings ◽  
Superior Corrosion Resistance ◽  
Corrosion Mechanisms ◽  
Steel Substrates ◽  
Crn Coatings

The Ni-alloy/CrN nanolayered coatings, Ni-Al/CrN and Ni-P/CrN, were deposited on (100) silicon wafer and AISI 420 stainless steel substrates by dual-gun sputtering technique. The influences of the layer microstructure on corrosion behavior of the nanolayered thin films were investigated. The bilayer thickness was controlled approximately 10 nm with a total coating thickness of . The single-layer Ni-alloy and CrN coatings deposited at were also evaluated for comparison. Through phase identification, phases of Ni-P and Ni-Al compounds were observed in the single Ni-alloy layers. On the other hand, the nanolayered Ni-P/CrN and Ni-Al/CrN coatings showed an amorphous/nanocrystalline microstructure. The precipitation of Ni-Al and Ni-P intermetallic compounds was suppressed by the nanolayered configuration of Ni-alloy/CrN coatings. Through Tafel analysis, the and values ranged from –0.64 to –0.33 V and to  A/, respectively, were deduced for various coating assemblies. The corrosion mechanisms and related behaviors of the coatings were compared. The coatings with a nanolayered Ni-alloy/CrN configuration exhibited a superior corrosion resistance to single-layer alloy or nitride coatings.

Effect of RE on Microstructure and Electrochemical Corrosion Behavior of Arc Sprayed Zn-Al-Mg Coating

2011 ◽  
Vol 66-68 ◽  
pp. 727-730 ◽  
Author(s):  
Zi Xin Zhu ◽  
Dong Chen ◽  
Bin Shi Xu
Keyword(s):  
Corrosion Behavior ◽  
Low Carbon Steel ◽  
Electrochemical Corrosion ◽  
Arc Spraying ◽  
Uniform Corrosion ◽  
Low Carbon ◽  
Discernible Effect ◽  
Electrochemical Corrosion Behavior ◽  
Superior Corrosion Resistance ◽  
Steel Substrates

Cored wires and arc spraying technique were used to produce Zn-Al-Mg-RE alloy coatings on low carbon steel substrates. The effect of RE (where RE is Rare Earth) on the microstructure and electrochemical corrosion behavior of coatings was investigated comparing with Zn-Al-Mg coatings. With addition of RE, the Zn-Al-Mg-RE coating has denser microstructure and fewer porosity. But RE has no discernible effect on the adhesion strength between coating and substrate. The Zn-Al-Mg-RE coating has superior corrosion resistance compared to Zn-Al-Mg coating due to the formation of more compact and uniform corrosion products. The role of the RE elements appears to be associated with the self-sealing process and the refinement of the coating microstructure.

Computational and Experimental Insights into the Role of Acidic Molecules on the Corrosion Behavior on 7A46 Aluminum Alloy

2021 ◽  
Vol 21 (4) ◽  
pp. 2221-2233
Author(s):  
Yaru Liu ◽  
Qinglin Pan ◽  
Xiangdong Wang ◽  
Ye Ji ◽  
Qicheng Liu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Corrosion Behavior ◽  
First Principles ◽  
First Principles Calculations ◽  
Corrosive Media ◽  
Corrosion Depth ◽  
Corrosion Mechanisms ◽  
Nanoscale Level

The corrosion mechanisms for different corrosive media on the aged 7A46 aluminum alloy were systematically investigated at nanoscale level. The combination of empirical intergranular and exfoliation corrosion behavior was employed, and coupled with first-principles calculations. Results revealed that the dispersed distribution of matrix precipitates (MPs) leads to the enhancement of the corrosion resistance pre-ageing (PA) followed by double-ageing (PA-DA) alloy. The deepest corrosion depth of PA-DA alloy was in hydrochloric acid, and the calculation result demonstrates that the passivation effect in combination with the accumulation of corrosion products in nitric acid protect the PA-DA alloy from further corrosion.

Hot Corrosion of Nimonic 105 in Sodium Sulfate-Sodium Chloride Melts

CORROSION ◽  
1981 ◽  
Vol 37 (7) ◽  
pp. 392-407 ◽  
Author(s):  
C. A. C. Sequeira ◽  
M. G. Hocking
Keyword(s):  
Sodium Chloride ◽  
Corrosion Behavior ◽  
Analytical Methods ◽  
Sodium Sulfate ◽  
Hot Corrosion ◽  
Corrosion Potential ◽  
Free Corrosion Potential ◽  
Chloride Melts ◽  
Ni Alloy ◽  
Potential Decay

Abstract The corrosion behavior of Nimonic 105 in molten Na2SO4, NaCl, and mixtures of these two salts, at 900 C, in laboratory air and under O2 + SO2/SO3 atmospheres has been evaluated by potentiodynamic, potential decay, and free corrosion potential measurements. In addition, the corrosion products were examined using several electron-optical techniques, and by other analytical methods. Pure Na2SO4 in air did not seem to be very corrosive towards Nimonic 105. Addition of NaCl to the molten Na2SO4 resulted in increased dissolution of Nimonic 105, which was in general nonuniform, alloy constituents nickel and cobalt dissolving more than others. Evidence of internal attack and enhancement of dissolution of the Ni alloy by SO3 was significant only when the corrosion conditions were prolonged. In pure NaCl, catastrophic corrosion occurs, which has been attributed to the depletion, dissolution, and vaporization of some alloy species.

scholarly journals Synergetic Effects of Temperature and Perpendicular Magnetic Field on Zn-Ni Alloy Electrodepositing Process

2021 ◽  
Vol 33 (11) ◽  
pp. 2839-2844
Author(s):  
N. Benachour ◽  
S. Chouchane ◽  
J.P. Chopart
Keyword(s):  
Nickel Alloys ◽  
Synergetic Effect ◽  
Electrochemical Analysis ◽  
X Ray Diffraction ◽  
X Ray ◽  
Acid Bath ◽  
Ni Alloy ◽  
Adsorbed Intermediate ◽  
Effects Of Temperature ◽  
Steel Substrates

The zinc-nickel alloys were electrodeposited on stainless steel substrates during a chloride acid bath. The electroplating processes were investigated under a moderate perpendicular magnetic flux at uncommon temperatures. The coatings obtained were characterized by scanning microscopy (SEM) including EDX and X-ray diffraction (XRD). Chronopotentiometric curves were additionally implemented for electrochemical analysis. Structural analysis revealed that the obtained alloys consisted of a mix of the homogeneous phase γ-Ni3Zn22 and α-Zn-Ni at 70 ºC. The alloys variations observed within the chemical composition, crystallographic phases and morphology of the alloys. It is often explained particularly, by the progressive hydrogen reaction and therefore the evolution of the adsorbed intermediate species. The synergetic effect was significant at 70 ºC within the 1T field, including the appearance of normal co-deposition.

The influence of deposition conditions and bilayer thickness on physical-mechanical properties of CA-PVD multilayer ZrN/CrN coatings

2018 ◽  
Vol 140 ◽  
pp. 189-196 ◽  
Author(s):  
Olga Maksakova ◽  
Sonia Simoẽs ◽  
Alexander Pogrebnjak ◽  
Oleksandr Bondar ◽  
Yaroslav Kravchenko ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Bilayer Thickness ◽  
Crn Coatings ◽  
Deposition Conditions
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