scholarly journals Magnesium, aluminum and zinc co-substituted hydroxyapatite: anti-corrosion properties

2019 ◽  
Vol 66 (4) ◽  
pp. 496-506
Author(s):  
Lenka Šimková ◽  
Petra Šulcová
Keyword(s):  
Corrosion Inhibition ◽  
Precipitation Method ◽  
Corrosion Properties ◽  
Accelerated Corrosion ◽  
Content Type ◽  
Corrosion Tests ◽  
Synthesis Conditions ◽  
Preliminary Corrosion ◽  
Accelerated Corrosion Test ◽  
Two Phases

Purpose The purpose of this study was to investigate the influence of doping ions Mg2+, Zn2+, Al3+ to the structure of hydroxyapatite (HAP; Ca10(PO4)6(OH)2) and subsequently to evaluate their adaptation in structure and their anticorrosive properties. Design/methodology/approach The substituted hydroxyapatite was synthesized by precipitation method that included the addition of Mg2+, Zn2+ and Al3+ containing precursors to partially replace Ca2+ ions in the hydroxyapatite structure. For precipitation synthesis, three ratios of Ca/P = 1; 1.67; 3 and two values of pH = 7 and 12 were selected. Samples 1 (Ca/P = 1; pH = 7), 2 (Ca/P = 1.67; pH = 7), 3 (Ca/P = 3; pH = 7) and 5 (Ca/P = 1.67; pH = 12) were chosen to monitor the influence of doping ions Mg2+, Zn2+ and Al3+ to the structure of hydroxyapatite and its anticorrosive properties. Findings The chosen synthesis conditions are appropriate for the formation of crystalline HAP substituted by elements Mg, Zn and Al. Only for one sample (1-Mg), two different phases (hydroxyapatite and whitlockite) were identified in the phase composition. On the basis of preliminary corrosion tests, pigments were divided into three groups pursuant to their anticorrosion effectivity: pigments with high corrosion-inhibition efficiency; pigments without anticorrosive properties; and pigments that promote corrosion processes. Originality/value In addition, no doping effect can be observed except for the sample 1-Mg, which consists of two phases (hydroxyapatite and whitlockite). Preliminary corrosion tests prove that some samples of HAP have extremely high anticorrosive effectivity as effectivity of the commercial pigments. The accelerated corrosion test showed that HAP samples have insufficient corrosion-inhibition properties for coating applications compared with the commercial pigment.

Effect of Artificial Aging on Intergranular Corrosion of 6063 Al Alloy

2013 ◽  
Vol 842 ◽  
pp. 275-278 ◽  
Author(s):  
Jian Ming Wang ◽  
Xiao Dan Meng ◽  
Ying Ying Bai ◽  
Guo Feng Ma ◽  
Yan Liu ◽  
...  
Keyword(s):  
Intergranular Corrosion ◽  
Corrosion Test ◽  
Artificial Aging ◽  
Al Alloy ◽  
Corrosion Properties ◽  
Corrosion Morphology ◽  
Accelerated Corrosion ◽  
Surface Corrosion ◽  
6063 Al Alloy ◽  
Accelerated Corrosion Test

The effect of artificial aging on the corrosion properties of 6063 Al alloy was investigated by optical microscope, field emission scanning electron microscope and accelerated corrosion test. Accelerated corrosion test revealed that the alloy was susceptible to intergranular corrosion (IGC) in the artificial aged conditions according to the surface corrosion morphology, and the IGC resistance was reduced as the aging time was prolonged, resulting from more Mg2Si grain boundary precipitates formed. However, the corroded cross-sections showed that the IGC was very local. Additionally, the surface corrosion morphology also showed that pitting corrosion took place, resulting from galvanic corrosion between (FeMn)3Si12Al15 particles and matrix Al.

scholarly journals Synergistic Inhibition Effect of Chitosan and L-Cysteine for the Protection of Copper-Based Alloys against Atmospheric Chloride-Induced Indoor Corrosion

2021 ◽  
Vol 22 (19) ◽  
pp. 10321
Author(s):  
Elena Messina ◽  
Chiara Giuliani ◽  
Marianna Pascucci ◽  
Cristina Riccucci ◽  
Maria Paola Staccioli ◽  
...  
Keyword(s):  
Amino Acid ◽  
Corrosion Inhibition ◽  
Protective Efficacy ◽  
Protective Film ◽  
Corrosion Properties ◽  
Accelerated Corrosion ◽  
Fourier Transformed Infrared Spectroscopy ◽  
Accelerated Corrosion Tests ◽  
Chloride Attack ◽  
Synergistic Inhibition Effect

The protection of metals from atmospheric corrosion is a task of primary importance for many applications and many different products have been used, sometimes being toxic and harmful for health and the environment. In order to overcome drawbacks due to toxicity of the corrosion inhibitors and harmful organic solvents and to ensure long-lasting protection, new organic compounds have been proposed and their corrosion inhibition properties have been investigated. In this work, we describe the use of a new environment-friendly anticorrosive coating that takes advantage of the synergism between an eco-friendly bio-polymer matrix and an amino acid. The corrosion inhibition of a largely used Copper-based (Cu-based) alloy against the chloride-induced indoor atmospheric attack was studied using chitosan (CH) as a biopolymer and l-Cysteine (Cy) as an amino acid. To evaluate the protective efficacy of the coatings, tailored accelerated corrosion tests were carried out on bare and coated Cu-based alloys, further, the nature of the protective film formed on the Cu-based alloy surface was analyzed by Fourier-transformed infrared spectroscopy (FTIR) while the surface modifications due to the corrosion treatments were investigated by optical microscopy (OM). The evaluation tests reveal that the Chitosan/l-Cysteine (CH/Cy) coatings exhibit good anti-corrosion properties against chloride attack whose efficiency increases with a minimum amount of Cy of 0.25 mg/mL.

Cyclic corrosion tests of organometallic coated fuel tanks

2016 ◽  
Vol 63 (2) ◽  
pp. 89-96 ◽  
Author(s):  
Patrícia Alves Saliba ◽  
Milene Adriane Luciano ◽  
Maria das Mercês Reis Castro ◽  
Vanessa Freitas Cunha Lins
Keyword(s):  
Electron Microscopy ◽  
Accelerated Corrosion ◽  
Content Type ◽  
Corrosion Tests ◽  
Accelerated Corrosion Tests ◽  
Fuel Tanks ◽  
Steel Tanks ◽  
Galvannealed Steel ◽  
Scanning Electron

Purpose – The purpose of this study is to evaluate the quality of organometallic coatings of automotive fuel tanks. Galvannealed steels and galvannealed steels coated with organometallic layers were analyzed using accelerated corrosion tests. Design/methodology/approach – The characterization of galvannealed and organometallic coatings was done by mass (layer removal and weighing) and layer thickness (glow discharge optical emission spectroscopy and scanning electron microscopy), chemical composition (energy dispersive spectroscopy) and surface morphology (scanning electron microscopy). The accelerated corrosion tests were performed in accordance with SAE J2334 and GMW 14872 standards. Findings – The samples tested using the GMW 14872 standard were more deteriorated as compared to the samples submitted to the SAE J2334 test because of the higher degree of aggressiveness of the GMW 14872 test. Despite the presence of white rust, the corrosion resistance of organometallic-coated steel samples was higher as compared to the resistance of galvannealed steel samples. Research limitations/implications – The organometallic coating is a commercial product, whose chemical composition is confidential. Practical implications – This study reinforces the quality of automotive tanks with organometallic coating and helps to increase their competitiveness in the market tanks as compared to polymeric tanks. Social implications – The study contributes to increase the competitiveness of steel tanks against polymeric tanks that meet the technical requirements but are not environmentally friendly because they are multi-layered and cannot be recycled. Originality/value – The novelty of this study is the comparison of the corrosion resistance of galvannealed steel tanks and galvannealed steel tanks with organometallic coatings. This corrosion evaluation joined with the physical and chemical characterization was not found in literature and is relevant to the materials selection of the automotive industry.

How label and nutritional claims affect consumers’ acceptance, buying intention and quality perception toward a beverage made from cashew nut

2019 ◽  
Vol 49 (6) ◽  
pp. 1243-1251 ◽  
Author(s):  
Marina Cabral Rebouças ◽  
Maria do Carmo Passos Rodrigues ◽  
Silvia Maria de Freitas
Keyword(s):  
New Product ◽  
Quality Attributes ◽  
Attitude Scale ◽  
Content Type ◽  
Cashew Nut ◽  
Significant Difference ◽  
Perception Of Quality ◽  
Two Phases ◽  
Mango Juice ◽  
Hedonic Scale

Purpose The purpose of this paper is to evaluate the influence of the front of a package label and the nutritional claims linked to it over consumers’ expectations as to acceptance, purchase attitude and perception of quality characteristics of a new functional beverage made from cashew nut milk and added with mango juice and prebiotic substances. Design/methodology/approach Three versions of the front label were developed, which differed just by the type of nutritional claim presented (“0 per cent lactose and 0 per cent cholesterol; 0 per cent lactose, 0 per cent cholesterol and source of fibers, 0 per cent lactose, 0 per cent cholesterol and antioxidants”) and were evaluated in two phases, expectation and informed. For the evaluation, consumers used a multi-attribute scale, the nine-point hedonic scale and a nine-point semi-structured buying attitude scale. Findings The labels created a positive expectation on the consumers regarding the quality attributes, overall impression (mean = 6.0 “Like slightly”) and buying attitude (mean = 6.0 “Would probably buy”). After tasting the beverage associated with labels (informed phase), consumers kept a positive evaluation. The t-test performed between the pair of means of both phases showed that there has not been a significant difference regarding the quality attributes (p > 0.05), special, attractive, nutritive, healthy and buying attitude (Label 1, p = 0.26; Label 2, p = 0.18; Label 3, p = 0.26) in all labels. Originality/value The authors evaluated how the influence of label and nutritional claims in regards to a new product, a beverage made from cashew nut, affects its acceptance, buying attitude and characteristics of quality. Until this moment, there are no studies that evaluate how external attributes affect the acceptance of this beverage totally unique in the Brazilian market.

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