scholarly journals Comparison on the immersion corrosion and electrochemical corrosion resistance of WC–Al2O3 composites and WC–Co cemented carbide in NaCl solution

RSC Advances ◽  
2021 ◽  
Vol 11 (36) ◽  
pp. 22495-22507
Author(s):  
Bin Han ◽  
Weiwei Dong ◽  
Bowen Fan ◽  
Shigen Zhu
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Corrosion ◽  
Cemented Carbide ◽  
Corrosion Mechanism ◽  
Nacl Solution ◽  
Immersion Corrosion ◽  
Electrochemical Corrosion Resistance

WC–Al2O3 composites possess higher corrosion resistance compared with WC–Co cemented carbide. The main corrosion mechanism for WC–Al2O3 composites is the oxidation of the WC phase.

Study on Anodic Oxidation of 2024 Aluminum Alloys in Sulfuric-Citric Acid

2014 ◽  
Vol 788 ◽  
pp. 236-242 ◽  
Author(s):  
Xiang Feng Meng ◽  
Guo Ying Wei ◽  
Xi Xi Zhao ◽  
Hong Liang Ge
Keyword(s):  
Corrosion Resistance ◽  
Citric Acid ◽  
Anodic Oxidation ◽  
Corrosion Potential ◽  
Electrochemical Corrosion ◽  
Mixed Solution ◽  
Nacl Solution ◽  
Maximum Hardness ◽  
Anodized Aluminum ◽  
Electrochemical Corrosion Resistance

Porous anodic alumina has been obtained through anodic oxidation in a mixed solution of sulfuric and citric acid. We investigated the microstructure and morphology of 2024 aluminum after being anodically oxidized under different voltage and temperature. Hardness and corrosion resistance of anodized aluminum has been also investigated. The results show that after anodization, many nanoholes appeared on the surface layer of the coating. Thickness of the anodized film increased from 2.7μm to 26.3μm with the voltage changing from 10 V to 18 V. Aodized films with the thickness of 18μm could be obtained under the temperature of 47°C. When the oxidation voltage is 12V, the hardness of the oxidation film reached 126HV. Maximum hardness (130 HV) could be achieved when the oxidation temperature was 57°C. After being dealt with in the NaCl solution, the electrochemical corrosion resistance of the anodic film got a sharp increase, and the anodic oxidation voltage had a great impact on the anodized film. When the oxidation voltage was 16V, the corrosion resistance of the film reached the highest value and the corrosion voltage was-0.7V. From the polarization curves, it has been found that the films obtained under the temperature of 37°C possessed more positive corrosion potential (-0.73V) and optimal anticorrosion performance.

Characterization of corrosion resistance of Zn-Ni-W and Zn-Ni-P-W heat-treated coatings

2021 ◽  
Vol 25 (3-4) ◽  
pp. 13-17
Author(s):  
Magdalena Popczyk ◽  
Jolanta Niedbała
Keyword(s):  
Corrosion Resistance ◽  
Phase Composition ◽  
Surface Morphology ◽  
Electrochemical Corrosion ◽  
Nacl Solution ◽  
Heat Treated ◽  
Electrochemical Corrosion Resistance

The paper presents results of research concerning the evaluation of corrosion resistance of heat-treated alloy coatings (Zn-Ni-W/320°C and Zn-Ni-P-W/320°C). The surface morphology and phase composition of the obtained coatings were determined. Electrochemical corrosion resistance was studied in 5% NaCl solution. On the basis of these studies it was found that the corrosion resistance of Zn-Ni-P-W/320°C coating is higher than Zn-Ni-W/320°C coating.

Electrochemical Corrosion of As-Cast and Annealed Zr48Cu36Al8Ag8 BMG in 0.1 M NaCl Solution

2016 ◽  
Vol 863 ◽  
pp. 65-69
Author(s):  
Jing Chie Lin ◽  
Mao Chia Huang ◽  
Ongki B. Anggriawan ◽  
Jason Shian Ching Jang ◽  
M. Agus Choiron
Keyword(s):  
Corrosion Resistance ◽  
Electrochemical Impedance ◽  
Electrochemical Corrosion ◽  
Open Circuit ◽  
Crystal Defects ◽  
Crystal Phase ◽  
Annealing Duration ◽  
Corrosion Mechanism ◽  
Nacl Solution ◽  
Cast Specimen

Electrochemical corrosion of as-cast and annealed zirconium-based bulk metallic glass (BMG) Zr48Cu36Al8Ag8 in 0.1 M NaCl solution was investigated in this work. The as-cast specimen, in complete amorphous form, contained null percent of crystal phase (denoted as 0C); however, the annealed ones contained 11, 25, 50, 75 and 100 % crystal phase (denoted as 11C, 25C, 50C, 75C and 100C, respectively) determined by the annealing duration of 0C specimen at 471 °C. Through monitoring of open circuit potential (OCP), measurements of direct-current polarization resistance (PR), Tafel plot (TP), cyclic anodic potentiodynamic polarization (CAPD), and electrochemical impedance spectroscopy (EIS), we found that the corrosion behavior of the Zr48Cu36Al8Ag8 was detremined by the the crystal phase present in the specemns dominated by the annealing durations. The corrosion resistance decreased in the order: 25C > 11C > 0C > 50C > 75C > 100C. This result revealed that the corrosion resistance inclined to be better and reached a mxmium with increasing the percentgae of the crystal phase from 0 to 25%; however, it decreased with further increasing the crystal phase over 25%. A corrosion mechanism is proposed to rationalize the sequence of corrosion resistance. According to the mechanism, the remained free volume and residual strain energy are responsible for the specimens containing crystal phase less than 25% (i.e., 0C, 11C and 25C); whereas crystal defects such as grain boundaries governed the corrosion of those containing crystal phase more than 25 % (i.e., 50C, 75C and 100C).

scholarly journals Corrosion resistance of the microarc oxidation coatings prepared on magnesium alloy

2018 ◽  
Vol 38 ◽  
pp. 02009
Author(s):  
Ying Lv ◽  
Jun Gang Li ◽  
Ming Zhong Wu ◽  
Zhen Ma ◽  
Jing Qiang Zhang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Microarc Oxidation ◽  
Electrochemical Corrosion ◽  
Ceramic Coatings ◽  
Nacl Solution ◽  
Oxide Coatings ◽  
Az91d Magnesium Alloy ◽  
Oxidation Technology ◽  
Electrochemical Corrosion Resistance

Ceramic coatings were prepared on the surface of AZ91D magnesium alloy by microarc oxidation technology. The effects of different voltages on morphology, phase composition and thickness of the coatings were characterized by SEM and XRD. The corrosion resistance of the coatings was measured by electrochemical workstation. Results indicated that the microarc oxidation coatings prepared in sodium silicate electrolyte exhibited porous surface and mainly comprised MgO, Mg2SiO4 and a small amount of MgAl2O4. The thickness of the oxide coatings increased rapidly with the increase of voltage. The coating prepared at 400V voltage had good electrochemical corrosion resistance in 3.5wt% NaCl solution.

scholarly journals Effects of Yttrium Addition on the Microstructure Evolution and Electrochemical Corrosion of SN-9zn Lead-Free Solders Al-Loy

Materials ◽  
2021 ◽  
Vol 14 (10) ◽  
pp. 2549
Author(s):  
Wenchao Yang ◽  
Jun Mao ◽  
Yueyuan Ma ◽  
Shuyuan Yu ◽  
Hongping He ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Microstructure Evolution ◽  
Electrochemical Corrosion ◽  
Lead Free ◽  
Nacl Solution ◽  
Rich Phase ◽  
Yttrium Addition ◽  
Electrochemical Corrosion Behavior ◽  
Lead Free Solders ◽  
Addition Amount

Electrochemical corrosion behavior of ternary tin-zinc-yttrium (Sn-9Zn-xY) solder alloys were investigated in aerated 3.5 wt.% NaCl solution using potentiodynamic polarization techniques, and the microstructure evolution was obtained by scanning electron microscope (SEM). Eight different compositions of Sn-9Zn-xY (x = 0, 0.02, 0.04, 0.06, 0.08, 0.10, 0.20, and 0.30 wt.%) were compared by melting. The experimental results show that when the content of Y reached 0.06 wt.%, the grain size of Zn-rich phase became the smallest and the effect of grain refinement was the best, but there was no significant effect on the melting point. With the increases of Y content, the spreading ratio first increased and then decreased. When the content of Y was 0.06 wt.%, the Sn-9Zn-0.06Y solder alloy had the best wettability on the Cu substrate, which was increased by approximately 20% compared with Sn-9Zn. Besides, the electrochemical corrosion experimental shows that the Y can improve the corrosion resistance of Sn-9Zn system in 3.5 wt.% NaCl solution, and the corrosion resistance of the alloy is better when the amount of Y added is larger within 0.02–0.30 wt.%. Overall considering all performances, the optimal performance can be obtained when the addition amount of Y is 0.06.

scholarly journals Microstructure and Corrosion Resistance of Underwater Laser Cladded Duplex Stainless Steel Coating after Underwater Laser Remelting Processing

Materials ◽  
2021 ◽  
Vol 14 (17) ◽  
pp. 4965
Author(s):  
Congwei Li ◽  
Jialei Zhu ◽  
Zhihai Cai ◽  
Le Mei ◽  
Xiangdong Jiao ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Phase Composition ◽  
Duplex Stainless Steel ◽  
Electrochemical Corrosion ◽  
Chemical Components ◽  
Laser Remelting ◽  
Underwater Environment ◽  
Underwater Laser ◽  
Electrochemical Corrosion Resistance

Combined with the technologies of underwater local dry laser cladding (ULDLC) and underwater local dry laser remelting (ULDLR), a duplex stainless steel (DSS) coating has been made in an underwater environment. The phase composition, microstructure, chemical components and electrochemical corrosion resistance was studied. The results show that after underwater laser remelting, the phase composition of DSS coating remains unchanged and the phase transformation from Widmanstätten austenite + intragranular austenite + (211) ferrite to (110) ferrite occurred. The ULDLR process can improve the corrosion resistance of the underwater local dry laser cladded coating. The corrosion resistance of remelted coating at 3 kW is the best, the corrosion resistance of remelted coating at 1kW and 5kW is similar and the corrosion resistance of (110) ferrite phase is better than grain boundary austenite phase. The ULDLC + ULDLR process can meet the requirements of efficient underwater maintenance, forming quality control and corrosion resistance. It can also be used to repair the surface of S32101 duplex stainless steel in underwater environment.

Effects of mass ratios on salt spray corrosion and electrochemical corrosion behaviors of laser cladded Cr–Ni coatings

2019 ◽  
Vol 66 (3) ◽  
pp. 352-359
Author(s):  
Li Jiahong ◽  
Kong Dejun
Keyword(s):  
Corrosion Resistance ◽  
Laser Cladding ◽  
Salt Spray ◽  
Electrochemical Corrosion ◽  
Corrosion Mechanism ◽  
H13 Steel ◽  
Content Type ◽  
Salt Spray Corrosion ◽  
Electrochemical Tests ◽  
Mass Ratios

Purpose The purpose of this paper is to improve the salt spray corrosion and electrochemical corrosion performances of H13 hot work mould steel, Cr–Ni coatings with the different Cr and Ni mass ratios are fabricated using a laser cladding (LC), which provides an experimental basis for the surface modification treatment of H13 steel. Design/methodology/approach Cr–Ni coatings with the different Cr and Ni mass ratios were firstly fabricated on H13 hot work mould steel using a laser cladding (LC). The salt spray corrosion (SSC) and electrochemical corrosion performances of Cr–Ni coatings in 3.5 Wt.% NaCl solution were investigated to analyze the corrosion mechanism, and the effect of mass ratios of Cr and Ni on their corrosion mechanism was discussed. Findings The laser cladded Cr–Ni coatings with the different Cr and Ni mass ratios are composed of Cr–Ni compounds, which are metallurgically combined with the substrate. The SSC resistance of Cr–Ni coating with the Cr and Ni mass ratios of 24:76 is the highest. The electrochemical corrosion resistance of Cr–Ni coating with the Cr and Ni mass ratio of 24:76 is the best among the three kinds of coatings. Originality/value In this study, the corrosion resistance of laser cladded Cr–Ni coatings with the Cr and Ni mass ratios of 17: 83, 20: 80 and 24: 76 was first evaluated using salt spray corrosion (SSC) and electrochemical tests, and the effect of mass ratios of Cr and Ni on their corrosion mechanism was discussed.

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