scholarly journals Improving electrochemical corrosion properties of ZE41A magnesium alloy via hydrothermal treatment

2021 ◽  
Vol 261 ◽  
pp. 02031
Author(s):  
Yuguang Zhang ◽  
Fan Zhang ◽  
Qingpeng Cheng ◽  
Xiuling Huang ◽  
Kai Zhang ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Pure Water ◽  
Matrix Material ◽  
Electrochemical Corrosion ◽  
Chemical Compositions ◽  
Hydrothermal Time ◽  
X Ray Diffraction ◽  
Corrosion Properties ◽  
Hydrothermal Temperature ◽  
Surface Morphologies

ZE41A magnesium alloy was selected as matrix material, using hydrothermal method for the synthesis of the surface coating. The formation of anti-corrosion coatings on the surface of magnesium alloy was investigated in pure water. By adjusting the experimental parameters such as the hydrothermal time (1-3 h) and the hydrothermal temperature (120-160 °C), the generation of the coating on the magnesium alloy surface is regulated. The surface morphologies, composition phase, and corrosion resistance of the hydrothermal conversion coatings were investigated by the method of scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray diffraction (XRD) and electrochemical corrosion tests. Results show that prolonged hydrothermal time and increased hydrothermal temperature change the morphologies as well as the chemical compositions of formed coatings from a relative loose structure with few magnesium hydroxides into a fine dense one with higher amount of magnesium hydroxide.

Electrochemical Corrosion Behaviors of Ti2AlNb with Double Glow Plasma Surface Chromized

2007 ◽  
Vol 546-549 ◽  
pp. 1753-1758
Author(s):  
Wen Ping Liang ◽  
Zhong Xu ◽  
Qiang Miao ◽  
Xiao Ping Liu ◽  
Zhi Yong He
Keyword(s):  
Electrochemical Corrosion ◽  
X Ray Diffraction ◽  
Corrosive Media ◽  
Major Drawback ◽  
Plasma Surface ◽  
Ti2alnb Alloy ◽  
Corrosion Behaviors ◽  
High Temperature Structural Material ◽  
Glow Plasma ◽  
Surface Morphologies

Ti2AlNb orthorhombic alloy is a promising high temperature structural material for aero-industries due to its advantageous properties. However, insufficient wear-resistance is a major drawback that has restricted the actual uses of this alloy in many circumstances. A treatment of double glow plasma surface chromizing on Ti2AlNb alloy has been carried out as an attempt to resolve this problem. This paper mainly investigated the electrochemical corrosion behaviors of this alloy after chromizing. The microstructure of the chromized layer was analyzed by X-ray diffraction (XRD). The sectional morphology of chromized layer was surveyed through scanning electronic microscopy (SEM).The polarization curves of specimens in three corrosive media, 5% H2SO4, 5% HCl and 3.5% NaCl, were measured. The eroded surface morphologies were also surveyed by SEM. The results indicate that surface chromizing treatment slightly decrease the alloy’s corrosion resistance, but still exhibit good performance.

High Anticorrosive Properties of Hot-Dip 55 wt% Al-Zn-Si Coatings on Q235 Steel

2010 ◽  
Vol 146-147 ◽  
pp. 306-309
Author(s):  
Wen Li Yao ◽  
Qian Li ◽  
Mou Cheng Li ◽  
Jie Yu Zhang ◽  
Kuo Chih Chou
Keyword(s):  
Aluminum Content ◽  
Electrochemical Impedance ◽  
Chemical Compositions ◽  
Corrosion Properties ◽  
Q235 Steel ◽  
Analysis Techniques ◽  
Surface Analysis Techniques ◽  
Dendritic Phase ◽  
The Difference ◽  
Surface Morphologies

A comparative study of the morphology and anticorrosive behaviour of commercial 55 wt% Al-Zn-Si coatings (CC) and hot-dip 55 wt% Al-Zn-Si coatings (HD) on Q235 steel was performed by using surface analysis techniques and electrochemical measurements. Despite the ingredients of the Al-rich dendritic phase for HD coating similar to the ingredients for CC coating, aluminum content in the Zn-rich phase for HD coating was almost twice higher than aluminum content for CC coating. The difference of surface morphologies and chemical compositions in Zn-rich phases for the two 55 wt% Al-Zn-Si coatings could significantly affect their corrosion properties. The corrosion behavior of the two coatings was investigated in 0.01 mol L-1 NaCl + 0.01 mol L-1 NaHSO3 aqueous solution. Both polarization curve and electrochemical impedance spectroscopy results indicate HD coatings had much higher corrosion resistance than CC ones.

scholarly journals Pengaruh Waktu Hidrotermal terhadap Karakteristik Zeolite Socony Mobile-5 (ZSM-5) Tanpa Template Menggunakan Reaktor Autoclave

KOVALEN ◽  
2021 ◽  
Vol 7 (3) ◽  
pp. 208-213
Author(s):  
Mukhtar Ghozali ◽  
Gamaliel Tanaka ◽  
Muhammad Misbahussalam ◽  
Tifa Paramitha
Keyword(s):  
Raw Materials ◽  
Hydrothermal Process ◽  
Operating Conditions ◽  
Hydrothermal Time ◽  
X Ray Diffraction ◽  
Hydrothermal Temperature ◽  
X Ray ◽  
Materials Used ◽  
Autoclave Reactor ◽  
Silica Oxide

ZSM-5 is a synthetic zeolite which has a complex production process and is affected by operating conditions, such as temperature and time. In this study, synthesized ZSM-5 without template by hydrothermal method. An autoclave reactor was used for the hydrothermal process. The aim of this study was to investigate the effect of varied hydrothermal times of 24 and 48 hours with a hydrothermal temperature of 180oC on the characteristic of ZSM-5. The raw materials used were silica oxide and aluminum hydroxide as a source of silica and alumina. The synthesis results were characterized using X-Ray Diffraction (XRD). Based on XRD results, the best result was obtained in performed at 48 hours hydrothermal time indicating the formation of ZSM-5 material at the 22.2o position. The percentage crystallinity of the sample at the hydrothermal time of 48 hours was 51.3%.

Residual service life of erbium-modified AM50 magnesium alloy under corrosion and stress environment

Open Physics ◽  
2021 ◽  
Vol 19 (1) ◽  
pp. 797-807
Author(s):  
Miao Yang ◽  
Liyun Xing ◽  
Xiaobo Liu ◽  
Yuqi Dong ◽  
Zhaoyu Chen ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Structural Material ◽  
Service Life ◽  
Residual Service Life ◽  
Distilled Water ◽  
Nacl Solution ◽  
X Ray Diffraction ◽  
Stress Environment ◽  
Surface Morphologies ◽  
Residual Service

Abstract Magnesium alloy will decrease strength with corrosion in use, thus affecting their service life. Service life as a structural material under stress and corrosion is one focus of the magnesium alloy used as structural material, and how to improve the residual service life of magnesium alloy is an important scientific issue. The X-ray diffraction, scanning electron microscopy, and slow strain rate tensile (SSRT) tests are used to study the residual service life of erbium (Er) effect in the AM50 magnesium alloy in air, distilled water, and NaCl solution. The results show that after rare earth Er addition to the AM50, the white granular Al3Er intermetallic compound was formed. With Er content increasing, the quantity of Al3Er phase was increased and the volume of β-Mg17Al12 phase was decreased. The SSRT results show that residual service life ratio increased with the Er addition compare with no Er alloy in distilled water. However, in 3.5% NaCl solution, 0.5% Er alloy shows the best service life. Moreover, Er addition does not change the alloy fracture mode, which remains quasi-cleavage. The main cause of the decline in service life in magnesium alloys is the change in surface morphology owing to the pitting corrosion nucleation and growth, which affects the stress distribution of the sample. The mechanism of film cracking plays a major role in the fracture process with the Er increased to change the surface morphologies.

scholarly journals Stress Corrosion Behavior of AM50Gd Magnesium Alloy in Different Environments

Metals ◽  
2019 ◽  
Vol 9 (5) ◽  
pp. 616 ◽  
Author(s):  
Miao Yang ◽  
Xiaobo Liu ◽  
Zhiyi Zhang ◽  
Yulai Song
Keyword(s):  
Magnesium Alloy ◽  
Hydrogen Embrittlement ◽  
Stress Corrosion ◽  
Anodic Dissolution ◽  
Corrosion Behavior ◽  
Pure Water ◽  
Corrosion Current ◽  
Open Circuit ◽  
Distilled Water ◽  
Corrosion Properties

A new type of high strength corrosion-resistant magnesium alloy was prepared by adding 1% rare earth Gd to AM50 and then treated with hot extrusion method. The stress corrosion properties of the new materials in air, pure water, 0.5 mol/L NaCl, and 0.5 mol/L Na2SO4 solution were studied by the slow strain rate tensile (SSRT) test, in situ open circuit potential test, Tafel curve test, stereomicroscope, SEM, and EDS. The results showed the following. The stress corrosion sensitivity of the material in different environments was Na2SO4 > NaCl > distilled water > air. According to the Tafel curves measured at 0 and 100 MPa, the corrosion voltage decreased little and the corrosion current density increased rapidly under 100 Pa. This was because the film of the corrosion product ruptured to form a large cathode and a small anode, which resulted in a large instantaneous corrosion current. The mechanism of hydrogen embrittlement and anodic dissolution together affected the stress corrosion behavior of the alloy. In distilled water, hydrogen embrittlement played a major role, while in NaCl and Na2SO4 solution, hydrogen embrittlement and anodic dissolution were both affected. The direct reason of the stress corrosion crack (SCC) samples’ failure was the cracks expanding rapidly at the bottom of pit, which was caused by corrosion.

scholarly journals Synthesis of ZnMn2O4 nanostructure via hydrothermal method

2020 ◽  
Vol 9 (3) ◽  
pp. 58-62
Author(s):  
Linh Nguyen Le My ◽  
Nguyen Do Mai
Keyword(s):  
Hydrothermal Method ◽  
Calcination Temperature ◽  
Crystalline Form ◽  
Hydrothermal Time ◽  
X Ray Diffraction ◽  
Spinel Type ◽  
Hydrothermal Temperature ◽  
X Ray ◽  
Factors Influencing

In this study, the spinel-type ZnMn2O4 material was successfully synthesized via hydrothermal method. Several factors influencing the synthesis of material such as Zn/Mn mole ratio, hydrothermal temperature and calcination temperature were studied. The characterization of expected samples using X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier Transform Infrared (FTIR), surface area analysis (BET) was conducted. The XRD results indicated that the highly ordered crystalline form of spinel ZnMn2O4 was synthesized in the conditions: Zn/Mn mole ratio of 1:2, hydrothermal temperature of 120 °C, hydrothermal time of 24 h and calcination temperature of 500 °C.

Corrosion Behavior of Magnesium Alloy AX53 in Simulated Body Fluids

2009 ◽  
Vol 610-613 ◽  
pp. 1174-1178 ◽  
Author(s):  
Jun Wang ◽  
Rong Chang Zeng ◽  
Jun Chen ◽  
Rong Shi Chen
Keyword(s):  
Magnesium Alloy ◽  
Corrosion Behavior ◽  
Room Temperature ◽  
The Other ◽  
Electrochemical Technique ◽  
Chemical Compositions ◽  
X Ray Diffraction ◽  
Free Corrosion Potential ◽  
X Ray ◽  
Initial Stage

Magnesium alloys have attracted scientists’ attention as potential implant materials, due to their excellent biocompatibility and good mechanical compatibility. Potentiodynamic electrochemical technique was applied to investigate the corrosion behavior of magnesium alloy AX53 (Mg-4.76Al-3.17Ca) in Hank's solutions, 0.9 wt% NaCl+0.7 g/L NaHCO3 solutions and 0.9 wt% NaCl solutions at room temperature. Corrosion morphologies of the alloys were observed by means of scanning electron microscope, and the chemical compositions were examined through x-ray diffraction. The results demonstrated that free corrosion potential (Ecorr) of AX53 in 0.9 wt % NaCl solution rose rapidly at initial stage, and then stabilized, whereas Ecorr of this alloy increased continuously in the other two solutions. Corrosion rates in Hank’s solutions were lower than in the other solutions. Intergranular corrosion occurred in these solutions.

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