Influence of In Situ MgO Coating on Corrosion Resistance of Pure Magnesium in Normal Saline

2009 ◽  
Vol 79-82 ◽  
pp. 1039-1042
Author(s):  
Li Chen Zhao ◽  
Chun Xiang Cui ◽  
Shuang Jin Liu ◽  
Yu Min Qi
Keyword(s):  
Corrosion Resistance ◽  
Normal Saline ◽  
Oxide Coating ◽  
Corrosion Current ◽  
Pure Magnesium ◽  
Heat Treated ◽  
Order Of Magnitude ◽  
Porous Oxide ◽  
Biological Performance

Magnesium and its alloys are potential biodegradable materials due to their outstanding biological performance, but their poor corrosion resistance greatly limits their applications as bone implants. This paper investigates the influence of in situ magnesium oxide coating on corrosion resistance of pure magnesium in normal saline. It was discovered by SEM that rough and porous oxide coatings were obtained on the surface of the pure magnesium after heat-treated at 400~500°C and the samples were severely corroded after immersion in 0.9 wt.% NaCl solution for 3 days. It also showed that the weight loss rates of the treated pure magnesium (TPM) samples were about 5~6 times higher than that of the untreated pure magnesium (UPM) sample. Electrochemical measurements showed that the corrosion current density (icorr) of the TPM samples was one order of magnitude higher than that of the UPM sample.

Influence of HF-SCG Immersion Treatment on Corrosion Resistance of the Ultrasonic Micro-Arc Oxidation Bio-Coating on Pure Magnesium

2014 ◽  
Vol 633 ◽  
pp. 402-405
Author(s):  
Mu Qin Li ◽  
Jiang Liu ◽  
Jun Gang Li ◽  
Ding Sen Cai ◽  
Yong Hui Zhao
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Potential ◽  
Electrochemical Corrosion ◽  
Corrosion Current ◽  
Ceramic Coatings ◽  
Pure Magnesium ◽  
Electrolyte System ◽  
Order Of Magnitude ◽  
Micro Arc Oxidation ◽  
Compound Coatings

Ceramic coatings were fabricated on pure magnesium in silicate electrolyte system by ultrasonic micro-arc oxidation (UMAO) process, and then silica sol (CSG) and HF-CSG treatment were carried out on micro-arc oxidation coatings. The corrosion potential (Ecorr) and corrosion current density (Icorr) of the compound coatings were analyzed by electrochemical corrosion workstation. The corrosive morphology of the coatings was observed by scanning electron microscopy (SEM). Results showed that the Ecorr of the coating with CSG and HF-CSG treatment increased by 55 mV and 69 mV respectively in comparison with that of single UMAO coating, and its Icorr reduced an order of magnitude, which had enhanced the corrosion resistance.

scholarly journals A new environmentally-friendly route to in situ form a high-corrosion-resistant nesquehonite film on pure magnesium

RSC Advances ◽  
2020 ◽  
Vol 10 (58) ◽  
pp. 35480-35489 ◽  
Author(s):  
Xianlong Cao ◽  
Quanyou Ren ◽  
Youkun Yang ◽  
Xianglong Hou ◽  
Yongbo Yan ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Environmentally Friendly ◽  
Pure Magnesium ◽  
Protective Film ◽  
High Corrosion Resistance ◽  
Corrosion Resistant ◽  
High Corrosion

A nesquehonite protective film with high corrosion resistance was prepared on pure Mg via a new environmentally-friendly in situ carbonation route.

Surface Treatments of Stainless Steel by Electroless Silver Coatings as a Bipolar Plate for Proton Exchange Membrane Fuel Cells

2015 ◽  
Vol 12 (6) ◽  
Author(s):  
Ing-Bang Huang ◽  
Ching Chiang Hwang
Keyword(s):  
Corrosion Resistance ◽  
Fuel Cell ◽  
Current Density ◽  
Corrosion Current Density ◽  
Proton Exchange Membrane ◽  
Corrosion Current ◽  
Proton Exchange ◽  
Heat Treated Sample ◽  
Heat Treated ◽  
Exchange Membrane

The objective of this study is to examine the effect of heat treatment at various temperatures on the corrosion behavior of electroless silver-coated SS 304 in a simulated proton exchange membrane (PEM) fuel cell environment. The corrosion properties of this material were studied using a potentiodynamic polarization technique. X-ray diffraction (XRD) patterns, polarization curves, and scanning electron microscopy (SEM) of coated and heat-treated specimens obtained in various heating temperatures were also utilized. It was found that the corrosion potential of the coated and heat-treated specimens shift toward a noble potential, and a significant decrease in corrosion current density was also observed. The corrosion current density decreased by a factor of about 1/500 for the heat-treated sample of 600 °C compared to the substrate. The heat-treated specimens displayed greater corrosion resistance than unheated and bare ones. According to the polarization studies and SEM images, the heat-treated specimen at 600 °C shows excellent corrosion resistance with a homogeneous dense surface morphology. These results demonstrated the coatings were suited for fuel cell applications in the proton exchange membrane fuel cell (PEMFC) environment.

Double Sealing of Ultrasonic Micro-Arc Oxidation Coating on Pure Magnesium by Nano-SiO2 Particles and SiO2 Sol Sealing Agent

2014 ◽  
Vol 1030-1032 ◽  
pp. 48-51
Author(s):  
Wei Wei Sun ◽  
Mu Qin Li ◽  
Yan Gao ◽  
Jiang Liu
Keyword(s):  
Corrosion Resistance ◽  
Bone Growth ◽  
Corrosion Current ◽  
Pure Magnesium ◽  
Infrared Spectrometry ◽  
Nano Sio2 ◽  
Micro Arc Oxidation ◽  
Sio2 Particles ◽  
Si Content ◽  
Sealing Coating

A double sealing coating was prepared on ultrasonic micro-arc oxidized pure magnesium substrate by adding nano-SiO2 particles as additive in the plating solution and coating SiO2 sol as sealing agent. The bonding characters of SiO2 sol was analyzed by Fourier transformed infrared spectrometry (FTIR). The compositions and morphology of seal coating were characterized by energy-dispersive X-ray spectroscopy (EDS) and scanning electron microscopy (SEM), respectively. The corrosion resistance of the micro-arc oxidized and the sealed pure magnesium substrate were studied. The results showed that the Si content increased gradually with the addition of nano-SiO2 particles and the SiO2 sol sealing. It was benefit to create bioactive MgSiO3, which promoted the bone growth. The double sealed pure magnesium had a self-corrosion potential shifted positively by 60mV as well as a self-corrosion current density decreased by a half in a 3.5wt% NaCl solution, showing good corrosion resistance.

scholarly journals Selective Laser Melting of 316L Stainless Steel: Influence of Co-Cr-Mo-W Addition on Corrosion Resistance

Metals ◽  
2021 ◽  
Vol 11 (4) ◽  
pp. 597
Author(s):  
Bolin Li ◽  
Tingting Wang ◽  
Peizhen Li ◽  
Shenghai Wang ◽  
Li Wang
Keyword(s):  
Stainless Steel ◽  
Corrosion Resistance ◽  
Selective Laser Melting ◽  
Scanning Speed ◽  
Corrosion Current ◽  
Laser Melting ◽  
Two Samples ◽  
Order Of Magnitude ◽  
The Difference ◽  
Tensile Experiment

The selective laser melting (SLM) of o-Cr-Mo-W/316L composite with 10wt% Co-Cr-Mo-W addition to 316 L stainless steel (SS) powder is produced to explore it’s the corrosion behavior. The tensile experiment of SLM composites is also measured to investigate the difference between the two samples. The optimum parameters of SLM 316 L SS and it’s composite samples are obtained by adjusting laser power and scanning speed with the relative density of 99.04 ± 0.69 and 99.15 ± 0.43. The yield strength of samples is increased from 731.96 MPa to 784.09 MPa after doping, and no obvious crack or fracture failure in the tensile samples are observed, indicating that the excellent plasticity is still maintained. The corrosion resistance of samples is improved largely with an order of magnitude lower corrosion current density than that of 316 L SS and increasing of 277 mv of epit Ep. The addition of Cr element in the doped powder contributes to the formation of the passivated film containing Cr. The different pitting corrosion pit occurs mainly around the pre-existing pores of the powder and further extends outward to form pits with the increase of voltage.

scholarly journals Roles of Graphene Additives in Optimizing the Microstructure and Properties of Ni–Cr–Graphene Coatings

Coatings ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 104 ◽  
Author(s):  
Liang Meng ◽  
Qinyou Hu ◽  
Chaojian Shi ◽  
Changhai Huang
Keyword(s):  
Corrosion Resistance ◽  
Crystallite Size ◽  
Rietveld Refinement ◽  
Microstructure Evolution ◽  
Corrosion Current ◽  
Micro Hardness ◽  
Electrodeposition Technique ◽  
Graphene Coating ◽  
Order Of Magnitude ◽  
Corrosion Behaviors

The electrodeposition technique was used to fabricate graphene and Cr particle-reinforced Ni–Cr–graphene coatings. The Rietveld refinement was utilized to analyze the microstructure of Ni deposits in the coatings. The properties including micro-hardness and corrosion behaviors of the coatings were also tested. Results showed that the addition of graphene particles contributed to the dendrite like structure on the surface of the Ni–Cr–graphene coating. The crystallite size and [200] texture of the Ni deposits in the Ni–Cr–graphene coatings were significantly decreased by the graphene particles. The crystallite size of 149.8 nm in the Ni-25–Cr-0–graphene coating was reduced to 35 nm in the Ni-25–Cr-8–graphene coating due to the addition of 8 g/L graphene to the electrolyte. The microstructure evolution of the Ni–Cr–graphene coatings brought about an enhancement in micro-hardness and corrosion resistance of the coatings. The micro-hardness of the coatings was improved from 260.1 HV0.2 of the pure Ni coating to 285.9 HV0.2 of the Ni-25–Cr-0–graphene coating and continually to 461.8 HV0.2 of the Ni-25–Cr-8–graphene coating. In corrosion solution (3.5 wt.% NaCl), the corrosion current (6.22 μA/cm2) of the Ni-25–Cr-0–graphene coating could be decreased by about an order of magnitude through the addition of graphene particles, which was 0.33 μA/cm2 for the Ni-25–Cr-8–graphene coating.

scholarly journals The Preparation and Properties of the Brown Film by Micro-arc Oxidized on In-Situ TiB2/7050Al Matrix Composites

Coatings ◽  
2020 ◽  
Vol 10 (7) ◽  
pp. 615
Author(s):  
Cunjuan Xia ◽  
Jie Huang ◽  
Jiongming Tao ◽  
Shuyang Wang ◽  
Ling Cai ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
Alkaline Electrolyte ◽  
Matrix Composites ◽  
Al Composite ◽  
White Film ◽  
Alkaline Electrolytes ◽  
Micro Arc Oxidation

The brown or grayish-white color films were prepared by the micro-arc oxidation (MAO) method on in-situ TiB2/7050Al composites using these alkaline electrolytes with/without KMnO4 as an additive. The microstructure, elemental composition, chemical state and corrosion behavior have been investigated by the microstructure characterizations and electrochemistry measurements on the MAO films comparatively. The results indicated that a brown film was obtained via adding KMnO4 into the alkaline electrolyte. The coloration mechanism of the brown color can be ascribed to the existence of MnO inside the film. Furthermore, the initiation of corrosion to the Al composite was intensively hindered by the brown MAO film. Compared with the Al substrate and grayish-white film, the brown MAO film exhibited the elevated corrosion potential and reduced corrosion current. Therefore, the brown film has presented an optimized corrosion resistance for the composite.

scholarly journals In Situ Preparation and Corrosion Resistance of a ZrO2 Film on a ZrB2 Ceramic

Coatings ◽  
2019 ◽  
Vol 9 (7) ◽  
pp. 455 ◽  
Author(s):  
Haitao Yang ◽  
Jian Zhang ◽  
Junguo Li ◽  
Qiang Shen ◽  
Lianmeng Zhang
Keyword(s):  
Corrosion Resistance ◽  
Photoelectron Spectroscopy ◽  
Electrochemical Impedance ◽  
Alkaline Solutions ◽  
Hydrogen Electrode ◽  
In Situ Preparation ◽  
Composition And Structure ◽  
Naoh Solution ◽  
Order Of Magnitude

ZrO2 films were in situ prepared using the anodic passivation of a ZrB2 ceramic in alkaline solutions. The composition and structure of the films were characterized using field-emission scanning electron microscopy (FE-SEM), Raman spectroscopy, and X-ray photoelectron spectroscopy (XPS). The corrosion resistances were evaluated in 0.1 M oxalate solution using the potentiodynamic polarization method (PDP) and the electrochemical impedance spectroscopy (EIS) technique. The results show that ZrO2 films can be prepared using anodization from −0.8 to 0.8 V standard hydrogen electrode (SHE) in 2–16 M NaOH solutions. During the anodization, the dehydration reaction of Zr(OH)4 to ZrO2 caused the volume shrinkage and tensile stress of the films. When the thickness of the films exceeded a critical value, the mud-cracking morphology occurred. The films without cracks exhibited the inhibition effect and provided effective corrosion protection in a 0.1 M H2C2O4 solution, which had a positive correlation with the film thickness. The film obtained when put in an 8 M NaOH solution (near the critical thickness) was found to significantly improve its corrosion resistance when put in a 0.1 M H2C2O4 solution by almost one order of magnitude compared with the bare ceramic.

scholarly journals Properties of Titanium Oxide Coating on MgZn Alloy by Magnetron Sputtering for Stent Application

Coatings ◽  
2020 ◽  
Vol 10 (10) ◽  
pp. 999
Author(s):  
Shusen Hou ◽  
Weixin Yu ◽  
Zhijun Yang ◽  
Yue Li ◽  
Lin Yang ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Magnetron Sputtering ◽  
Titanium Oxide ◽  
Photoelectron Spectroscopy ◽  
Oxide Coating ◽  
Corrosion Current ◽  
Tio2 Coating ◽  
X Ray ◽  
Titanium Oxide Coating ◽  
Angle Method

Constructing surface coatings is an effective way to improve the corrosion resistance and biocompatibility of magnesium alloy bioabsorbable implants. In this present work, a titanium oxide coating with a thickness of about 400 nm was successfully prepared on a MgZn alloy surface via a facile magnetron sputtering route. The surface features were characterized using scanning electron microscopy (SEM), atomic force microscopy (AFM), X-ray diffraction (XRD), X-ray photoelectron spectroscopy (XPS), and the contact angle method. The corrosion behavior and biocompatibility were evaluated. The results indicated that the amorphous TiO2 coating with a flat and dense morphology was obtained by magnetron-sputtering a titanium oxide target. The corrosion current density decreased from 1050 (bare MgZn alloy) to 49 μA/cm2 (sample with TiO2 coating), suggesting a significant increase in corrosion resistance. In addition, the TiO2 coating showed good biocompatibilities, including significant reduced hemolysis and platelet adhesion, and increased endothelial cell viability and adhesion.

Influence of Cr and Mn Addition and Heat Treatment on the Corrosion Behaviour of an AlSi3Mg Alloy

2017 ◽  
Vol 754 ◽  
pp. 11-14 ◽  
Author(s):  
Marialaura Tocci ◽  
Lorenzo Montesano ◽  
Annalisa Pola ◽  
Marcello Gelfi ◽  
Marina La Vecchia
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Corrosion Resistance ◽  
Corrosion Current Density ◽  
Corrosion Behaviour ◽  
Base Alloy ◽  
Corrosion Current ◽  
Nacl Solution ◽  
Heat Treated ◽  
Mechanical Properties And Corrosion

In the present work, the effect of Cr and Mn addition on corrosion resistance was investigated on AlSi3Mg alloy. Potentiondynamic corrosion tests in a 3.5 wt. % NaCl solution were performed on samples in different heat-treated conditions, and corrosion current density and potential were determined by Tafel method. Brinnel hardness measurements were also carried out in order to couple corrosion resistance with mechanical properties. It was interestingly found that Cr presence enhanced mechanical properties and corrosion resistance in comparison with the base alloy.

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