Structure and Property of Ce Conversion Coating on Magnesium Alloys

2012 ◽  
Vol 616-618 ◽  
pp. 1819-1822
Author(s):  
Lu Tie Xu ◽  
Jun Yan ◽  
Yi Guo ◽  
Shi Guo Du
Keyword(s):  
Electron Microscope ◽  
Magnesium Alloy ◽  
Scanning Electron Microscope ◽  
Magnesium Alloys ◽  
Test System ◽  
Conversion Coating ◽  
Electrochemical Test ◽  
Structure And Property ◽  
Corrosion Medium ◽  
Scanning Electron

Ce conversion coating was prepared on the surface of magnesium alloy, and formation of Ce conversion coating was discussed. Structure and resistance to corrosion were measured by scanning electron microscope and electrochemical test system. The results showed the Ce conversion coating was composed of three layers, and it could effectively protect magnesium alloy from corrosion medium.

scholarly journals Influence of Multi-Holes on Fatigue Behaviors of Cast Magnesium Alloys Based on In-Situ Scanning Electron Microscope Technology

Materials ◽  
2018 ◽  
Vol 11 (9) ◽  
pp. 1700 ◽  
Author(s):  
Xi-Shu Wang ◽  
Chang-Hao Tan ◽  
Juan Ma ◽  
Xiao-Dong Zhu ◽  
Qing-Yuan Wang
Keyword(s):  
Fatigue Crack ◽  
Electron Microscope ◽  
Crack Initiation ◽  
Scanning Electron Microscope ◽  
Magnesium Alloys ◽  
Mg17al12 Phase ◽  
Cast Magnesium Alloys ◽  
Cast Magnesium ◽  
Scanning Electron

The low cycle fatigue tests on the crack initiation and propagation of cast magnesium alloys with two small holes were carried out by using in-situ scanning electron microscope (SEM) observation technology. The fatigue crack propagation behaviors and fatigue life, which are affected by two small artificial through holes, including the distances between two holes and their locations, were discussed in detail based on the experimental results and the finite element analysis (FEA). The results indicated that the fatigue multi-cracks occurred chiefly at the edges of two holes and the main crack propagation was along the weak dendrite boundary with the plastic deformation vestiges on the surface of α-Mg phase of cast AM50 and AM60B alloys. The fatigue cracking characteristics of cast AZ91 alloy depended mainly on the brittle properties of β-Mg17Al12 phase, in which the multi-cracks occurred still at the edges of two holes and boundaries of β-Mg17Al12 phase. The fatigue crack initiation position of cast magnesium alloys depends strongly on the radius of curvature of through hole or stress concentration factor at the closed edges of two through holes. In addition, the fatigue multi-cracks were amalgamated for the samples with titled 45° of two small holes of cast Mg-Al alloys when the hole distance is less than 4D (D is the diameter of the small hole).

Effects of NaOH Concentration on Properties of Micro Arc Coatings on Magnesium Alloys

2012 ◽  
Vol 482-484 ◽  
pp. 909-913 ◽  
Author(s):  
Shu Fang Zhang ◽  
Rong Fa Zhang ◽  
Wen Kui Li ◽  
Yi Min Zhong
Keyword(s):  
Corrosion Resistance ◽  
Electron Microscope ◽  
Scanning Electron Microscope ◽  
Magnesium Alloys ◽  
Environmental Scanning ◽  
Nacl Solution ◽  
Base Solution ◽  
Polarization Test ◽  
Micro Arc Oxidation ◽  
Scanning Electron

Anodic coatings were prepared by micro arc oxidation on AZ91HP in a base solution of 18 g/L Na2SiO3 ּ9H2Oand 4 g/L tannic acid with 5-20 g/l NaOH. The influence of NaOH concentration on final voltage and corrosion resistance were studied. The morphologies of anodic coatings were determined by environmental scanning electron microscope (ESEM). Potentiodynamic polarization test was performed in 3.5wt.% NaCl solution to evaluate the corrosion resistance of anodic coatings. The results show that the NaOH concentration has greatly effect on the final voltage, the compositions, thickness, morphologies and corrosion resistance. The corrosion resistance of anodic coatings is the best in the base solution containing 10 g/l NaOH.

Age-Hardening Response of Mg-Al-Sn Alloys

2015 ◽  
Vol 828-829 ◽  
pp. 250-255
Author(s):  
Abu Syed Humaun Kabir ◽  
Jing Su ◽  
Mehdi Sanjari ◽  
In Ho Jung ◽  
Stephen Yue
Keyword(s):  
Electron Microscope ◽  
Aluminum Alloys ◽  
Scanning Electron Microscope ◽  
Magnesium Alloys ◽  
Isothermal Aging ◽  
Precipitation Hardening ◽  
Metallic Alloys ◽  
Mg Alloys ◽  
Age Hardening ◽  
Scanning Electron

Precipitation hardening has been used before as one of the most effective strengthening methods for many metallic alloys. However, this method has not been studied completely in magnesium alloys, and the numbers of precipitation hardenable wrought Mg alloys are still very limited compared to aluminum alloys and steels. The age hardening responses of Mg-Al-Sn alloys in cast-homogenized condition were investigated by isothermal aging at 200°C for prolonged time. It was found that hardness can be improved significantly for the alloy with higher amounts of tin. The improvement in hardness was reasoned by the formation of precipitates. The shapes and morphology of the precipitates were different depending on the orientations of the grains. The precipitates were characterized by scanning electron microscope.

Synthesis and Evaluation of Benzohydrazide Derivative as a Corrosion Protector for Magnesium Alloy in 3%Nacl

2021 ◽  
Author(s):  
RAJA KALIYAPERUMAL ◽  
T.KASILINGAM
Keyword(s):  
Weight Loss ◽  
Electron Microscope ◽  
Magnesium Alloy ◽  
Scanning Electron Microscope ◽  
Alkaline Medium ◽  
Energy Dispersive ◽  
Cathodic Process ◽  
X Ray ◽  
Nyquist Plots ◽  
Scanning Electron

Abstract Inhibition action of 4-Chloro-N(3,4,5-trimethoxybenzilidene) benzohydrazide on the corrosion of magnesium alloy in alkaline medium was investigated by weight-loss technique, Nyquist spectra, Tafel plot, scanning electron microscope and energy dispersive x-ray analysis. Tafel curves of magnesium alloy showed both anodic and cathodic process suppressed. Nyquist plots, scanning electron microscope and energy dispersive x-ray analysis studies provide the confirmatory evidence for the protection of magnesium alloy by the studied inhibitor.

Investigation of degraded bone substitutes made of magnesium alloy using scanning electron microscope and nanoindentation

2020 ◽  
Vol 109 ◽  
pp. 103825
Author(s):  
Ann-Kathrin Gartzke ◽  
Stefan Julmi ◽  
Christian Klose ◽  
Silke Besdo ◽  
Anja-Christina Waselau ◽  
...  
Keyword(s):  
Electron Microscope ◽  
Magnesium Alloy ◽  
Scanning Electron Microscope ◽  
Bone Substitutes ◽  
Scanning Electron

Effects of Strontium and Calcium on the Microstructure and Grain Size of Cast AZ91 Magnesium Alloy

2011 ◽  
Vol 264-265 ◽  
pp. 789-794
Author(s):  
A. Kiani ◽  
M. Emamy ◽  
E. Fadaei ◽  
Saber Ghannadi
Keyword(s):  
Grain Size ◽  
Electron Microscope ◽  
Magnesium Alloy ◽  
Scanning Electron Microscope ◽  
Phase Distribution ◽  
Optical Microscope ◽  
Uniform Structure ◽  
Az91 Magnesium Alloy ◽  
Az91 Magnesium ◽  
Scanning Electron

The experiments focused on the influence of strontium and calcium as additional alloying elements on the grain size and phase distribution of AZ91 magnesium alloys. For this purpose, different concentrations of Sr (0.01, 0.1, 0.4, and 0.8) and Ca (0.01, 0.1, 0.4, 0.6 and 0.78) were added. The microsturctural examination of specimens was made by an optical microscope and scanning electron microscope. From obtained results it was found that using 0.4 wt% strontium can provide a fine and uniform structure.

Failure Behavior of Anodized Coating-Magnesium Alloy Substrate Structures

2004 ◽  
Vol 261-263 ◽  
pp. 363-368 ◽  
Author(s):  
Xi Shu Wang ◽  
Xi Qiao Feng ◽  
Xing Wu Guo
Keyword(s):  
Electron Microscope ◽  
Magnesium Alloy ◽  
Crack Initiation ◽  
Scanning Electron Microscope ◽  
Void Nucleation ◽  
Failure Behavior ◽  
Sem Images ◽  
Bulk Substrate ◽  
Bending Loading ◽  
Scanning Electron

This work focuses on the damage mechanisms and the resulting failure behavior of structures made of anodized coatings on magnesium alloy substrates. The failure of anodized coatings of about 30µm thickness on AZ91D substrates was investigated under three-points bending loading with online scanning electron microscope (SEM) observations. The obtained SEM images show that void nucleation and crack initiation occurs mainly at sites near the coating-substrate interface, and the evolutionary microcracking damage diffuses from the interface to the coating surface and also to the bulk substrate with the increasing in loading.

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