Study on the Technology of the Environment-Friendly Conversion Coating Containing Phytic Acid for Magnesium Surface

2009 ◽  
Vol 610-613 ◽  
pp. 905-910 ◽  
Author(s):  
Ji Xing Lin ◽  
Li Yuan Niu ◽  
Guang Liang Gao
Keyword(s):  
Phytic Acid ◽  
Ph Value ◽  
Conversion Coating ◽  
Immersion Method ◽  
Environment Friendly ◽  
Waste Gas ◽  
Whole Process ◽  
Coating Formation ◽  
Magnesium Surface ◽  
Surface Conversion

An anticorrosion conversion coating on metal magnesium surface was prepared using immersion method in an aqueous solution containing mainly phytic acid. The coating after the preparation could be dry in the air without a rinse process using water in the final stage. Hence there is no discharge of waste water and waste gas in the whole process. Influence of several factors on the anticorrosion performance of coating was tested. And optimal parameters in the coating formation process were obtained from orthogonal test. The results indicated that the coating had better corrosion resistance, when the solution contained 3% phytic acid, and the immersion time is 7 minutes and the PH value was 3.5. The surface conversion coating was characterized by SEM and EDS. The conversion coating is better than the traditional chromate passive film by testing corrosion speed of coatings using hydrogen evolution method. The technology of the environment-friendly conversion coating containing phytic acid has the potential to be a new anti-corrosion technology for magnesium surface.

Study on Preparation and the Characteristics of Environment-Friendly Ce-Ti-Mn Conversion Coating on Aluminum Alloy 6061

2014 ◽  
Vol 881-883 ◽  
pp. 1385-1390
Author(s):  
Xian Fang Yang ◽  
Tian Quan Liang ◽  
Wei Wei ◽  
Dong Hui Deng ◽  
Guang Qiao Xu ◽  
...  
Keyword(s):  
Corrosion Resistance ◽  
Aluminum Alloy ◽  
Room Temperature ◽  
Ph Value ◽  
Conversion Coating ◽  
Environment Friendly ◽  
Aluminum Alloy 6061 ◽  
Coating Characteristics ◽  
Surface Morphologies ◽  
Alloy 6061

Preparation and the characteristics of environment-friendly Ce-Ti-Mn conversion coating on aluminum alloy 6061 were investigated by XRD, FESEM, EDS, TEM and AFM in this paper. It is indicated that coating characteristics such as the surface morphologies, microstructure and corrosion resistance, are greatly influenced by the formation technology at room temperature. The constituents and their concentration, and pH value of the conversion solution have an important role on the feature of Ce-Ti-Mn conversion film, which will significantly influence on the continuity, compactness and the crystalline structure of particles of the film. The concentrations of the main salt K2TiF6and oxidizer KMnO4have significant effect on the characteristics of the conversion coating. The Ce-Ti-Mn film grows in a lamellar way, composing of oxide and/ or hydroxide phases of Ce, Ti and Mn, some of which are amorphous. The formation mechanism of the Ce-Ti-Mn conversion coating is discussed in detail.

Dyeing processes of 100% bio-based and degradable polylactide/poly (hydroxybutyrate-co-hydroxyvalerate) textiles

2016 ◽  
Vol 87 (17) ◽  
pp. 2066-2075 ◽  
Author(s):  
ZH Zhang ◽  
ZQ Xu ◽  
XX Huang ◽  
XM Tao
Keyword(s):  
Polyethylene Terephthalate ◽  
Energy Cost ◽  
Textile Industry ◽  
Ph Value ◽  
Bath Temperature ◽  
Low Energy ◽  
Environment Friendly ◽  
Bursting Strength ◽  
Whole Process ◽  
Dyeing Process

This paper reports an investigation of dyeing processes of textiles made from a novel 100% bio-based and fully degradable polylactide/poly (hydroxybutyrate-co-hydroxyvalerate) (PLA/PHBV) fiber. The dye exhaustion, depth of shade and fastness, as well as bursting strength of dyed PLA/PHBV fabrics have been evaluated in terms of types and concentration of dyestuff, dyeing bath temperature, duration, liquor ratio and pH value. Finally, the energy cost of the whole dyeing process of the proposed material is calculated and compared with that of polyethylene terephthalate. The experimental results show that an excellent dyeing effect and bursting strength can be achieved by properly applied dyes (e.g. C.I. Disperse Orange 30, Red 74, and Blue 79) under optimal low-dyeing-temperature conditions (100℃, 10 min, pH 5, LR 30:1). In addition, considering the low energy cost during the whole process, PLA/PHBV fibers can be regarded as a promising and environment-friendly material for the textile industry.

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.

The Study about Environmentally-Friendly Passivation Technology Process and Performance on Brass Surface

2011 ◽  
Vol 399-401 ◽  
pp. 1967-1971
Author(s):  
Hong Yin Xu ◽  
Li Li
Keyword(s):  
Corrosion Resistance ◽  
Phytic Acid ◽  
Passive Film ◽  
Ph Value ◽  
Sodium Molybdate ◽  
Solution Ph ◽  
Sulfosalicylic Acid ◽  
Passivation Film ◽  
Brass Surface ◽  
And Performance

The paper through the synergy before mixed Phytic acid and Sodium molybdate, Sulfosalicylic acid, Organic silane, and add the active substances PEG, Optimize the Passivation liquid formula of Brass surface, Phytic acid is the main ingredient, study the affection of Phytic acid Passive film Corrosion resistance on the three main Passivation conditions: Passivation temperature, time and Passivation solution PH value. The results show that，Phytic acid passivation film process recipes as follows：Phytic acid (quality score 50%) 2~5ml/L, sodium molybdate 4~8g/L, organic material 10~30ml/L, sulfosalicylic acid 3~7g/L, polyethylene glycol 2~6g/L, deactivated temperature 30~35°C, pH value 5, deactivated time 60s. The test showed that，the phytic acid passive film can obviously enhance the anti-corrosive performance on the brass surface, its corrosion resistance proportion chromates passive film is fairly good.

scholarly journals Mechanism of the process of decomposition of apatitis with phosphoric acid

2019 ◽  
Vol 81 (1) ◽  
pp. 294-297
Author(s):  
R. F. Sabirov ◽  
A. F. Makhotkin ◽  
Yu. N. Sakharov ◽  
I. A. Makhotkin ◽  
I. Yu. Sakharov
Keyword(s):  
Phosphoric Acid ◽  
Ph Value ◽  
Batch Reactor ◽  
Experimental Studies ◽  
Hydrogen Ions ◽  
Experimental Conditions ◽  
Monocalcium Phosphate ◽  
Ph Values ◽  
Whole Process ◽  
Proportional Increase

Experimental studies of the kinetics and mechanism of the process, decomposition of apatite by phosphoric acid, in the Apatite-H3PO4-H2O system without the addition of sulfuric acid have been performed. The study of the decomposition process of Kovdorsky apatite with certain particle sizes was carried out in a batch reactor with a volume of 1 dm3 with stirring of the reaction mixture, and an initial concentration of phosphoric acid of 17% by weight, at a temperature of 78–82 °C. Observation of the process was carried out by determining the concentration of phosphoric acid and the concentration of monocalcium phosphate. The acidity of the reaction mixture was determined by the pH meter readings (pH-105 MA with a glass combined-ESC-10603 electrode). It was shown that during the whole process a constant smooth increase in the pH value of the reaction mixture to pH 6 occurs. Comparison of the pH values of the reaction mixture during the actual at the time of determining the concentration of phosphoric acid and pH of phosphoric acid of the corresponding concentration in the aqueous solution shows that the pH value of the reaction mixture is significantly affected by the presence of monocalcium phosphate gel. During the process, during the first thirty minutes, the concentration of phosphoric acid decreases from 17 to 10% by weight, the corresponding quantitative formation of monocalcium phosphate gel and a proportional increase in the pH of the reaction mixture. Then, as the concentration of phosphoric acid decreases, the process slows down and does not proceed to the end under the experimental conditions. The dependence of the concentration of hydrogen ions in the reaction mixture on the time of the process of decomposition of apatite in phosphoric acid, which is presented in logarithmic coordinates, shows that the mechanism of formation of hydrogen ions during the whole process does not change. Thus, it is shown that the process of decomposition of apatite by phosphoric acid in the Apatite-H3PO4-H2O system proceeds with the formation of an intermediate product - monocalcium phosphate gel. When this occurs, a corresponding significant change in the pH values of the reaction mixture occurs. During the whole process there is a constant decrease in the concentration of phosphoric acid.

scholarly journals Trivalent chromium conversion coating formation on aluminium

2015 ◽  
Vol 280 ◽  
pp. 317-329 ◽  
Author(s):  
J.-T. Qi ◽  
T. Hashimoto ◽  
J.R. Walton ◽  
X. Zhou ◽  
P. Skeldon ◽  
...  
Keyword(s):  
Trivalent Chromium ◽  
Conversion Coating ◽  
Coating Formation
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