Study on the corrosion resistance of phytic acid conversion coating for magnesium alloys

2006 ◽  
Vol 201 (3-4) ◽  
pp. 1536-1541 ◽  
Author(s):  
Liu Jianrui ◽  
Guo Yina ◽  
Huang Weidong
Keyword(s):  
Corrosion Resistance ◽  
Phytic Acid ◽  
Magnesium Alloys ◽  
Conversion Coating

Catechol/polyethyleneimine conversion coating with enhanced corrosion protection of magnesium alloys: potential applications for vascular implants

2018 ◽  
Vol 6 (43) ◽  
pp. 6936-6949 ◽  
Author(s):  
Hao Zhang ◽  
Lingxia Xie ◽  
Xiaolong Shen ◽  
Tengda Shang ◽  
Rifang Luo ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Surface Modification ◽  
Magnesium Alloys ◽  
Corrosion Protection ◽  
Conversion Coating ◽  
Good Corrosion Resistance ◽  
Potential Applications

A catechol/polyethyleneimine conversion coating on a MgZnMn alloy possessed good corrosion resistance. Heparin was further grafted on it and this showed the potential for surface modification of magnesium-based vascular implants.

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.

scholarly journals Effect of Native Oxide Film on Commercial Magnesium Alloys Substrates and Carbonate Conversion Coating Growth and Corrosion Resistance

Materials ◽  
2014 ◽  
Vol 7 (4) ◽  
pp. 2534-2560 ◽  
Author(s):  
Sebastián Feliu, Jr. ◽  
Alejandro Samaniego ◽  
Elkin Bermudez ◽  
Amir El-Hadad ◽  
Irene Llorente ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Oxide Film ◽  
Magnesium Alloys ◽  
Conversion Coating ◽  
Native Oxide ◽  
Coating Growth

Properties of Conversion Coating of Magnesium Alloys by a Phosphate-Permanganate Solution

2005 ◽  
Vol 488-489 ◽  
pp. 665-668 ◽  
Author(s):  
Shu Sen Wu ◽  
Ming Zhao ◽  
Ji Rong Luo ◽  
You Wu Mao
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloys ◽  
Adhesion Force ◽  
Conversion Coating ◽  
Resistance Test ◽  
Az91d Alloy ◽  
Conversion Coatings ◽  
Good Adhesion ◽  
Better Than

A chromium-free conversion coating for AZ91D magnesium alloys has been obtained by using a phosphate-permanganate solution. Examinations have been carried out on the conversion coating for morphology, composition, adhesion force and corrosion resistance. Results show that the conversion coatings are relatively uniform and continuous, with thickness from 7µm to 10µm. They exhibit good adhesion to matrix and have some non-penetrate tiny holes on the surface. The main elements of the conversion coating of AZ91D alloy are Mg、O、P、K、Al、Mn. Results of corrosion resistance test indicate that the corrosion resistance of the conversion coating by phosphate-permanganate solution is in match to that of the conversion coating formed in a chromate solution, but for the corrosion resistance after painting, the former is better than the later.

Influencing Factors of Phytic Acid Conversion Coating on AZ91 Magnesium Alloy

2011 ◽  
Vol 239-242 ◽  
pp. 2336-2341
Author(s):  
Yan Ling Lu ◽  
Yan Kun Chen ◽  
Shi Guo Du ◽  
Yi Guo ◽  
Qing Hong
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloy ◽  
Phytic Acid ◽  
Acid Concentration ◽  
Ph Value ◽  
Conversion Coating ◽  
Metal Corrosion ◽  
Anode Current Density ◽  
Az91 Magnesium Alloy ◽  
Az91 Magnesium

AZ91 magnesium alloy is selected as the matrix metal. SEM, EDS, Tafel and EIS were adopted and spot test was carried out to investigate the influence of pH value, phytic acid concentration, temperature,conversion time on corrosion resistance of conversion coatings. Result shows that process of phytic acid forming is the controlled metal corrosion process and the uneven surface pattern reflects the different chemical properties of two-phase current on magnesium alloy surface, which is implied by the conversion surface. It is proved by the test that pH value is committed the most to the corrosion resistance of the conversion coating, and the next is the phytic acid concentration. It is found that the corrosion resistance of the conversion coating is the best when pH value of the conversion solution is 4.5; The conversion coating has little influence on the cathode reaction dynamics, however, more importantly, it changes the dynamics of the alloy electrode anode solution reaction, therefore, the alloy’s anode current density decreases while the corrosion resistance of magnesium alloy is enhanced.

Conversion coating treatment for AZ31 magnesium alloys by a phytic acid bath

2009 ◽  
Vol 39 (10) ◽  
pp. 1857-1862 ◽  
Author(s):  
C. H. Liang ◽  
R. F. Zheng ◽  
N. B. Huang ◽  
L. S. Xu
Keyword(s):  
Phytic Acid ◽  
Magnesium Alloys ◽  
Conversion Coating ◽  
Acid Bath ◽  
Az31 Magnesium Alloys

Research on a Technique of Eco-Friendly Chemical Conversion Coating

2013 ◽  
Vol 800 ◽  
pp. 162-165
Author(s):  
Rong Xia Zhu ◽  
Zheng Miao ◽  
Cui Xiang Wang
Keyword(s):  
Corrosion Resistance ◽  
Magnesium Alloys ◽  
Chemical Conversion ◽  
Conversion Coating ◽  
Chemical Conversion Coating

A Technology of eco-friendly chemical conversion coating on magnesium alloys by phosphate-permanganate was studied. The performances of blank sample and chrome-free chemical conversion coating on Mg-based alloys were studied. The morphology and corrosion resistance of chemical conversion coating were tested by metallographic microscope and corrosive test. The best technology condition is that the concentration of KMnO4 is 20g/L, Na3PO4 is 100g/L, KF is 40g/L, and the pH is 7~8, the temperature is 50°C．The time of the chemical conversion is 40min.

Phosphate Conversion Coating on Diecast AZ91D and Its Corrosion Resistance

2005 ◽  
Vol 488-489 ◽  
pp. 819-822 ◽  
Author(s):  
Wan Qiu Zhou ◽  
Da Yong Shan ◽  
En Hou Han ◽  
Wei Ke
Keyword(s):  
Corrosion Resistance ◽  
Corrosion Rate ◽  
Magnesium Alloys ◽  
Polarization Curve ◽  
Immersion Test ◽  
Amorphous Structure ◽  
Conversion Coating ◽  
Test Results ◽  
Complex Phosphate

A phosphate conversion coating was deposited on diecast AZ91D magnesium alloys, the film was a complex phosphate containing Mg and Al,which showed amorphous structure. Corrosion resistance of conversion coating in 3.5%NaCl was investigated by polarization curve. It was showed that the anodic branch of polarization curve for the phosphate conversion coating presented typical passivation characteristic. Immersion test results showed that the corrosion rate of phosphate conversion coating was less than that of chromate Dow7 film.

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