Anticorrosion Conversion Coating Content Lanthanum and Phosphate on Foam Mg Alloy

2011 ◽  
Vol 299-300 ◽  
pp. 211-214 ◽  
Author(s):  
Li Yuan Niu ◽  
Zi Mu Shi ◽  
Ji Jing Lin ◽  
Yong Li ◽  
Lin Chao Xu ◽  
...  
Keyword(s):  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Rare Earths ◽  
Manufacturing Process ◽  
Conversion Coating ◽  
Hard Tissue ◽  
Vacuum Sintering ◽  
Elasticity Module ◽  
Anticorrosion Performance ◽  
Powder Manufacturing

Foam magnesium alloy was an idea substitute of hard tissue of human bodies because its elasticity module was close to the bone of human. In the paper, foam degradable magnesium alloys were prepared by “Press-Dissolution-Vacuum sintering-Hot treatment-Aging” powder manufacturing process firstly. Then samples were coated by immersion in a bath containing phosphate and rare earths lanthanum. Results show that, Mg-0.9Mn foam magnesium alloys after hot treatment had better anticorrosion performance; and coated foam magnesium alloys form the bath with phosphate lanthanum chloride had lower rate of degradation.

scholarly journals Improvement of bio-compatible AZ61 magnesium alloy corrosion resistance by fluoride conversion coating

2016 ◽  
Vol 60 (5) ◽  
pp. 132-138 ◽  
Author(s):  
J. Drábiková ◽  
F. Pastorek ◽  
S. Fintová ◽  
P. Doležal ◽  
J. Wasserbauer
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Simulated Body Fluid Solution ◽  
Conversion Coating ◽  
Az61 Magnesium Alloy ◽  
Wrought Magnesium Alloy ◽  
Consequent Effect ◽  
Materials Used ◽  
Short Time

Abstract Magnesium and its alloys are perspective bio-degradable materials used mainly due to their mechanical properties similar to those of mammal bones. Potential problems in utilization of magnesium alloys as bio-materials may relate to their rapid degradation which is associated with resorption problems and intensive hydrogen evolution. These problems can be eliminated by magnesium alloys surface treatment. Therefore, this work aims with analysis of the influence of fluoride conversion coating on corrosion characteristics of magnesium alloy. Unconventional technique by insertion of wrought magnesium alloy AZ61 into molten Na[BF4] salt at temperature of 450 °C at different treatment times was used for fluoride conversion coating preparation. The consequent effect of the coating on magnesium alloy corrosion was analyzed by means of linear polarization in simulated body fluid solution at 37 ± 2 °C. The obtained results prove that this method radically improve corrosion resistance of wrought AZ61magnesium alloy even in the case of short time of coating preparation.

Study on Chemical Conversion Treatment and Electroless Nickel Plating on AZ91D Magnesium Alloy

2010 ◽  
Vol 148-149 ◽  
pp. 698-701
Author(s):  
Xing Wu Qiu
Keyword(s):  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Galvanic Corrosion ◽  
Electroless Nickel ◽  
Chemical Conversion ◽  
Conversion Coating ◽  
Electroless Nickel Plating ◽  
Nickel Plating ◽  
Az91d Magnesium Alloy ◽  
High Microhardness

AZ91D magnesium alloy were used as the materials in this experiment. The directly electroless nickel plating, the stannate conversion processing and the electroless nickel plating on the surface of the magnesium alloys that have formed the stannate chemical conversion film on their surface were researched. The morphologies, anticorrosion ability and the hardness of plating of the magnesium alloys after chemical conversion processing and plating nickel were analysed by scanning electron microscope, salt droplet experiment, microhardness survey etc. The result of the experiment showed that, the conversion film unions with the substrate well, the conversion coating can avoid intense galvanic corrosion after the expiration of the plating, and enhanced the corrosion resistance of the plating. The nickel plating deposited on the conversion coating has high microhardness which could provide good protection for the magnesium alloys.

scholarly journals Anticorrosion Performance of LDH Coating Prepared by CO2 Pressurization Method

2018 ◽  
Vol 2018 ◽  
pp. 1-10 ◽  
Author(s):  
Xiaochen Zhang ◽  
Peng Jiang ◽  
Chunyan Zhang ◽  
Bateer Buhe ◽  
Bin Liu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Layered Double Hydroxides ◽  
Atmospheric Pressure ◽  
Az91d Alloy ◽  
Cross Sectional ◽  
Anticorrosion Performance ◽  
Double Hydroxides ◽  
First Time

Many surface treatment methods are used to improve the corrosion resistance of magnesium alloys. LDH (layered double hydroxides) conversion coatings are currently found in the most environmentally friendly and pollution-free coatings of magnesium alloy. In this study, the CO2 pressurization method was applied to the preparation of LDH coating on magnesium alloy for the first time. The effect of CO2 pressurization on the formation and corrosion resistance of LDH coating on AZ91D alloy was investigated. The hardness and adhesion were significantly higher on LDH coating in the case of CO2 pressurization than it is in atmospheric pressure. The surface and cross-sectional morphologies show that LDH coating is more compact in the case of CO2 pressurization than with atmospheric pressure. The results of the polarization curve, hydrogen evolution, and immersion tests indicate that the corrosion resistance of the LDH coating prepared by the CO2 pressurization method was significantly improved.

scholarly journals Electrochemical Corrosion Behaviour of ZE41 and QE22 Magnesium Alloys

2011 ◽  
Vol 690 ◽  
pp. 385-388 ◽  
Author(s):  
M. Bobby Kannan ◽  
Carsten Blawert ◽  
Wolfgang Dietzel
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Magnesium Alloys ◽  
Rare Earths ◽  
Pitting Corrosion ◽  
Corrosion Behaviour ◽  
Electrochemical Corrosion ◽  
Localized Corrosion ◽  
Az80 Magnesium Alloy ◽  
Electrochemical Corrosion Behaviour

The study suggests that the rare-earths containing magnesium alloys ZE41 and QE22 exhibit a poorer corrosion resistance than the AZ80 magnesium alloy. Electrochemical experiments showed that the two rare-earths containing alloys are highly susceptible to localized corrosion. Post corrosion analysis revealed intergranular and pitting corrosion in ZE41, whereas QE22 alloy underwent only pitting corrosion.

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.

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