scholarly journals The Immersion Corrosion Resistance of Shot Peening and MAO Applied on AZ31−0.5% La Sheets

2020 ◽  
Vol 10 (1) ◽  
pp. 5201-5204
Author(s):  
G. Elmansouri ◽  
I. H. Kara ◽  
H. Ahlatci ◽  
Y. Turen
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Shot Peening ◽  
Rolling Speed ◽  
Dominant Factor ◽  
Base Materials ◽  
Immersion Corrosion ◽  
Micro Arc Oxidation ◽  
The One ◽  
Hot Rolled

In this study, the effect of Shot Peening (SP) and Micro Arc Oxidation (MAO) process on the corrosion resistance of 0.5% La with added AZ31 Mg alloy, hot rolled at different rolling speeds, was investigated. It was found that the surface of the rolled material at a rolling speed of 4.7m/min had higher surface smoothness values than the one rolled at 10m/min. It was observed that the corrosion rate changed in the first 40 of 168 hours. In the following hours, the corrosion rate showed different results according to the initial microstructure properties of the base materials. Initially, pore size was the dominant factor determining corrosion resistance, although, after coating, the corrosion rate was affected by the twins formed, based on rolling speed, which enhanced the corrosion rate between 48 and 168 hours.

Fabrication and Characterization of a Biocompatible Coating Formed on a Heat-Treated Magnesium Alloy Using Micro-Arc Oxidation

2017 ◽  
Author(s):  
Hamdy Ibrahim ◽  
Mohammad Elahinia
Keyword(s):  
Heat Treatment ◽  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Mg Alloys ◽  
Corrosion Tests ◽  
Bone Fixation ◽  
Immersion Corrosion ◽  
Heat Treated ◽  
Micro Arc Oxidation

The fast corrosion rate of magnesium (Mg) alloys is the main problem associated with the use of such biocompatible alloys for bone fixation applications. The corrosion resistance of Mg alloys can be improved by different post-fabrication processes such as heat treatment and coating. We have heat-treated a biocompatible Mg-1.2Zn-0.5Ca (wt.%) alloy at optimized heat treatment parameters to achieve the highest mechanical strength and corrosion resistance. Afterwards, the heat-treated alloy was coated with a ceramic layer using micro arc oxidation (MAO) process to further enhance the corrosion resistance. The microstructure of the prepared samples was investigated using optical microscopy and scanning electron microscopy (SEM). The corrosion characteristics were determined by conducting in vitro electrochemical and immersion corrosion tests. The results showed that the heat treatment process successfully improved the mechanical and corrosion properties of the Mg-1.2Zn-0.5Mn (wt.%) alloy. Both the in vitro electrochemical and immersion corrosion tests showed that the MAO-coated samples have a significantly higher corrosion resistance which results in a significantly lower corrosion rate. This study indicated that the biocompatible coating produced by MAO process may be suitable for providing heat-treated Mg-Zn-Ca-based alloys with protection from corrosion towards synthesizing bone fixation materials in clinical application.

Effect of Electrolyte Composition on Corrosion Resistance in Nickel Plating Process for Coating Bonded Magnet PrFeB

2014 ◽  
Vol 896 ◽  
pp. 245-248 ◽  
Author(s):  
Candra Kurniawan ◽  
Hayati M.A. Sholihat ◽  
Kemas Ahmad Zaini Thosin ◽  
Muljadi ◽  
Prijo Sardjono
Keyword(s):  
Magnetic Properties ◽  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Nickel Coating ◽  
Electrolyte Composition ◽  
Nickel Metal ◽  
Sem Images ◽  
Average Value ◽  
Immersion Corrosion ◽  
Bonded Magnet

Despite of its excellence magnetic quality, one of the critical properties of PrFeB based permanent magnet is a low corrosion resistance so it can be oxidized easily which can reduce its magnetic properties. In this study, Nickel coating has been performed for bonded PrFeB magnet by the electroplating method using Nickel-Watts bath-type as the electrolyte to improve the corrosion resistance. The varying amount of the electrolyte compounds used to have the optimized composition indicated by the corrosion resistance measurement. The solution composition used was NiSO4 (230-380 g/L), NiCl2 (30-60 g/L), and H3BO3 (30 and 45 g/L) with a fixed value of other parameters. Characterization used including the immersion corrosion test, microstructure analysis, and magnetic properties. Based on the corrosion rate measurement, the highest corrosion resistant of Nickel coated PrFeB magnet achieved from the electrolyte composition of NiSO4: NiCl2: H3BO3 = 380: 60: 30 g/L with a plating time and current density (J) of 60 minutes and 40 mA/cm2 respectively. The corrosion rate data showed that the Nickel metal coating can improve the corrosion resistance of bonded PrFeB magnet up to 29 times than of the substrate. The SEM images showed that the thickness of the Nickel coating on the optimum electrolyte composition was in average value of 35.1 µm. The overall samples has a magnetic remanence value (Br) reached ≥ 6 kG, so it has enough properties to be applied in devices such as generators and electric motors.

scholarly journals Effect of Surface Nanocrystallization on Corrosion Resistance of the Conformed Cu-0.4%Mg Alloy in NaCl Solution

Metals ◽  
2018 ◽  
Vol 8 (10) ◽  
pp. 765 ◽  
Author(s):  
Dan Song ◽  
Jinghua Jiang ◽  
Xiaonan Guan ◽  
Yanxin Qiao ◽  
Xuebin Li ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
High Speed ◽  
Mg Alloy ◽  
Nacl Solution ◽  
Immersion Corrosion ◽  
Initial Stage ◽  
Wire Brushing ◽  
Dislocation Cells ◽  
Effect Of Surface

Surface nano-crystallization (SNC) of a conform-extruded Cu-0.4 wt.% Mg alloy was successfully conducted by high-speed rotating wire-brushing to obtain the deformed zone with dislocation cells and nanocrystallines. SNC promotes the anodic dissolution and corrosion rate of the Cu-Mg alloy in the initial stage of immersion corrosion in 0.1 M NaCl solution. The weakened corrosion resistance is mainly attributed to the higher corrosion activity of SNC-treated alloy. With extending the immersion time, the SNC-treated alloy slows the corrosion rate dramatically and exhibits uniform dissolution of the surface. The formation of the dense corrosion products leads to the improvement of overall corrosion performance. It indicates that the SNC-treated Cu-Mg alloy can function reliably for a longer duration in a corrosive environment.

Effect of adding rare-earth cerium on the microstructure and acid rain corrosion resistance of the ADC12 alloy

2021 ◽  
Vol 0 (0) ◽  
Author(s):  
LiJie Zhang ◽  
Hong Yan ◽  
YongCheng Zou ◽  
BaoBiao Yu ◽  
Zhi Hu
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Acid Rain ◽  
Corrosion Current Density ◽  
Corrosion Potential ◽  
Corrosion Current ◽  
The Self ◽  
Electrochemical Tests ◽  
Immersion Corrosion ◽  
Eutectic Si

Abstract The effect of adding cerium on the microstructure and acid rain corrosion resistance of the AlSi11Cu3 alloy was investigated by means of optical microscopy, scanning electron microscopy, and energy dispersive spectroscopy. The AlSi11Cu3 alloy was doped with varying stoichiometries of cerium to generate AlSi11Cu3-xCe, where x = 0, 0.5, 1.0, and 1.5 wt.%. The results show that the α-Al, eutectic Si, and β-Al5FeSi phases in the AlSi11Cu3-1.0Ce alloy are significantly refined. Electrochemical tests demonstrated an increase in the self-corrosion potential value of the AlSi11Cu3-1.0Ce alloy from –670 mV to –628 mV relative to the untreated alloy. In addition, the AlSi11Cu3-1.0Ce alloy has the lowest corrosion current density (8.4 μA × cm–2). Immersion corrosion testing on the AlSi11Cu3-1.0Ce alloy revealed a corrosion rate of 0.71 mg × cm–2 × d–1, constituting a 72% reduction in the corrosion rate compared to the untreated alloy. These results indicate that the AlSi11Cu3-1.0Ce alloy has a high resistance to acid rain corrosion, which is the result of a refinement of the cathode phases.

scholarly journals Effect of the Physicochemical Properties of Soils on Generalized and Localized Corrosion Rate of API X52 and X60 Pipeline Steels

2021 ◽  
Vol 5 (1) ◽  
pp. 1-10
Author(s):  
Contreras A
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Physicochemical Properties ◽  
Localized Corrosion ◽  
Homogeneous Microstructure ◽  
Corrosion Rates ◽  
Fine Grain ◽  
X52 Steel ◽  
The One ◽  
Best Fit

This work analyzed physicochemical properties of different types of soils on the generalized and localized corrosion rate in two steels (X52 and X60) most used in pipeline transportation of hydrocarbons. The physicochemical properties such moisture content, pH, resistivity and redox potential, which influence the corrosion rate of the pipelines were analyzed. Soils from three different sites in the south of México were obtained. Soils were sampled approximately 1.5 m deep, close to pipeline. From the analysis of generalized corrosion results taking into account the type of soil, it was observed that the most corrosive soil for the two steels was soil-3, generating corrosion rates of 0.119 and 0.097 mm/year, for the X52 and X60 steels respectively, after a period of 6 months. It is important to note that the maximum generalized corrosion rate was obtained after 1 month of exposure of the steels, generating corrosion rates of 0.177 and 0.162 mm/year, for the X52 and X60 steels respectively. In similar way, the localized corrosion rates for the both steels were higher when steels are exposed to Soil-3, generating corrosion rates of 1.1 and 0.45 mm/year, for X52 and X60 steel respectively, after a period of 6 months. In general it was observed that X60 steel presents greater resistance to pitting corrosion rate (in Soil-3), which can be attributed to its more homogeneous microstructure, fine grain size, and its chemical composition that presents elements such as Cr and Ni in greater quantity than X52 steel, which improve the corrosion resistance. However, depending on the type of soil the corrosion resistance behavior of each steel is different. From the analysis of various equations fits, it was determined that the potential equation is the one that gives the best fit for all cases.

Study Affection of Nano-Al2O3 Additive on the Corrosion Resistance of Micro-Arc Oxidation Film of Titanium Alloy TC4

2012 ◽  
Vol 472-475 ◽  
pp. 2707-2711 ◽  
Author(s):  
Pei Nian Wu ◽  
Guo Jun Niu ◽  
Jian Jun Xi ◽  
Jun Zhao
Keyword(s):  
Corrosion Resistance ◽  
Titanium Alloy ◽  
Surface Morphology ◽  
The Other ◽  
Compact Layer ◽  
Corrosion Resistant ◽  
Pore Area ◽  
Micro Arc Oxidation ◽  
The One ◽  
Α Al2o3

Study the affect of nano-Al2O3 additive on the MAO film of titanium ally, the affect of nano-Al2O3 additive on the surface morphology and the thickness is not remarkable, but the nano-Al2O3 additive is good to improve corrosion resistant of the film. The mechanism of nano-Al2O3 additive improving corrosion resistant of the film is that: on the one hand is improving the content of α- Al2O3 in the film, on the other hand is decreasing the size of the pore area of the film and improving the dense of the loose and compact layer.

Research and Application of Micro-Arc Oxidation Technology on Magnesium Alloy Motorcycle Key Parts

2014 ◽  
Vol 496-500 ◽  
pp. 63-70
Author(s):  
Xi Di Chen ◽  
Qi Zhou Cai ◽  
Zhi Wei Deng ◽  
Li Song Yin
Keyword(s):  
Corrosion Resistance ◽  
Layer Structure ◽  
Orthogonal Experiment ◽  
Amorphous Material ◽  
Mg Alloy ◽  
Additive Concentration ◽  
Corrosion Medium ◽  
Immersion Corrosion ◽  
Micro Arc Oxidation ◽  
Oxidation Technology

The micro-arc oxidation process parameters of AZ91D Mg alloy and Na2WO4 concentration were optimized by orthogonal experiment. SEM, EDX, XRD, potentiodynmic polarization and immersion corrosion test were carried out to investigate the morphologies, phase composition and corrosion resistance of the MAO coatings. The results shown that the MAO coating are mainly composed of MgOMg2SiO4MgAl2O4,MgWO4 and a small amount of amorphous material as well as with a double layer structure, outer loose and inner denser, the proper parameters and additive concentration were: 300Hz,5.0A/dm2,50%/50% and 2.0g/l Na2WO4. The MAO coatings coated under the proper condition on AZ91D Mg alloy motorcycle parts provided the far batter corrosion resistance than the substrate, suggesting that MAO coatings can effectively protect the motorcycle parts against the erosion from corrosion medium. Meanwhile, it also found that the irregular part shape has some influence on the coatings formation as well as corrosion resistance.

Enhanced Osteoblast Proliferation and Corrosion Resistance of Commercially Pure Titanium Through Surface Nanostructuring by Ultrasonic Shot Peening and Stress Relieving

2014 ◽  
Vol 40 (S1) ◽  
pp. 347-355 ◽  
Author(s):  
Shitu Jindal ◽  
Rajesh Bansal ◽  
Bijay P. Singh ◽  
Rajiv Pandey ◽  
Shankar Narayanan ◽  
...  
Keyword(s):  
Cell Proliferation ◽  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Shot Peening ◽  
Pure Titanium ◽  
Commercially Pure Titanium ◽  
Osteoblast Proliferation ◽  
Surface Nanostructuring ◽  
Commercially Pure ◽  
Ultrasonic Shot Peening

This investigation was carried out to study the effect of a novel process of surface modification, surface nanostructuring by ultrasonic shot peening, on osteoblast proliferation and corrosion behavior of commercially pure titanium (c p-Ti) in simulated body fluid. A mechanically polished disc of c p-Ti was subjected to ultrasonic shot peening with stainless steel balls to create nanostructure at the surface. A nanostructure (<20 nm) with inhomogeneous distribution was revealed by atomic force and scanning electron microscopy. There was an increase of approximately 10% in cell proliferation, but there was drastic fall in corrosion resistance. Corrosion rate was increased by 327% in the shot peened condition. In order to examine the role of residual stresses associated with the shot peened surface on these aspects, a part of the shot peened specimen was annealed at 400°C for 1 hour. A marked influence of annealing treatment was observed on surface structure, cell proliferation, and corrosion resistance. Surface nanostructure was much more prominent, with increased number density and sharper grain boundaries; cell proliferation was enhanced to approximately 50% and corrosion rate was reduced by 86.2% and 41% as compared with that of the shot peened and the as received conditions, respectively. The highly significant improvement in cell proliferation, resulting from annealing of the shot peened specimen, was attributed to increased volume fraction of stabilized nanostructure, stress recovery, and crystallization of the oxide film. Increase in corrosion resistance from annealing of shot peened material was related to more effective passivation. Thus, the surface of c p-Ti, modified by this novel process, possessed a unique quality of enhancing cell proliferation as well as the corrosion resistance and could be highly effective in reducing treatment time of patients adopting dental and orthopedic implants of titanium and its alloys.

Boundary Layers Refractory/Glass Melt and Glass Defects

2008 ◽  
Vol 39-40 ◽  
pp. 601-606 ◽  
Author(s):  
Michael Dunkl
Keyword(s):  
Boundary Layer ◽  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Boundary Layers ◽  
Corrosion Behaviour ◽  
The Other ◽  
Glass Melts ◽  
Good Corrosion Resistance ◽  
Protection Layer ◽  
The One

In this paper the formation of boundary layers and their behaviour regarding corrosion and glass defect potential of different refractory/glass melt combinations will be discussed. The reaction between refractories and glass melts is determined by the diffusion of the different ions from the glass melt into the refractory material and vice versa. The connected solution reactions lead to the formation of a saturation boundary layer, which influences the corrosion behaviour and the glass defect potential. The behaviour of the boundary layers of various refractory/glass melt types are partly complete different. On the one side there are refractory/glass melt combinations which form a relative thick reaction layer, on the other side there are refractory/glass melt combinations with very thin boundary layers. Thick reaction layers affect in the most cases like a protection layer with a good corrosion resistance, but there can be a relative high glass defect potential at operation changes. Thin reaction layers have for the most cases a low glass defect potential, but partly a higher corrosion rate.

scholarly journals STUDY ON ALTERNATE IMMERSION CORROSION BEHAVIOR AND MECHANISM OF SDCM DIE STEEL FOR HOT STAMPING

2021 ◽  
Vol 55 (5) ◽  
Author(s):  
Jiang Bin ◽  
Zuo Pengpeng ◽  
Wu Xiaochun
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Hot Stamping ◽  
High Hardness ◽  
Corrosion Damage ◽  
Uniform Corrosion ◽  
Tempering Temperature ◽  
Immersion Corrosion ◽  
Corrosion Pit ◽  
Pit Depth

In this paper, the alternate immersion corrosion test of Cr-Mo-V series SDCM steel for hot stamping was carried out, and different stresses were loaded with self-made fixture. The results shown that regardless of hardness and stress, the corrosion mode of the material is uniform corrosion. Stress could significantly increase the corrosion rate, with lower hardness and higher corrosion rate. Because of the existence of Corrosion Removal Layer (CRL), the maximum corrosion pit depth would be reduced. The maximum corrosion pit depth and Corrosion Pit density (CPD, ρv) were used to describe the degree of corrosion damage. From low to high hardness, the CPD ρv and corrosion resistance increased gradually. With the increased of tempering temperature, the hardness decreased, and the percentage of carbide area in the field of view increased from 16.36% to 24.32%. The irregular spherical carbide M23(C, N)6 rich in Cr coarsens and consumes Cr element in the material, which lead to the decrease of corrosion resistance. Through the polarization curve of the dynamic potential, we known that the current density was increased with the hardness decreased, from 28.53 μA/mm2 to 40.93 μA/mm2.

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