Deterioration Characteristics of Overlapping Layers between Al-5Mg Thermal Spray Coating and Heavy-Duty Paint Coating

2019 ◽  
Vol 972 ◽  
pp. 235-240 ◽  
Author(s):  
Mu Ye Yang ◽  
Kazuyoshi Muto ◽  
Shigenobu Kainuma ◽  
Jin Xuan Du ◽  
Hirokazu Miyata

In recent years, Al-5Mg alloy thermal spray coatings have been used as an anti-corrosion coating applied for various components of steel structures, in some cases it was covered by the conventional heavy-duty coating. However, the deterioration characteristics of overlapping layers between thermal spray layer and heavy-duty paint coating still not clear. In this study, to compare the anti-corrosion characteristics of the single thermal spray coating and overlapping layers, the accelerated cyclic exposure tests were carried out on specimens with three types of coating layers. To clarify the deterioration characteristics, the cross-cut defect were introduced into specimens, and the EIS measurements, glossiness test, EPMA elemental analyses were conducted on test specimens. The test results indicated that the deterioration of the overlapping layer at the steel base-exposed portion occurs earlier than the case of Al-5Mg thermal spray coating. In addition, the deterioration of thermal spray coating was accelerated by the sealing treatment in specimen with overlapping layers.

2017 ◽  
Vol 754 ◽  
pp. 55-58
Author(s):  
Shigenobu Kainuma ◽  
Jin Xuan Du ◽  
Mu Ye Yang ◽  
Kazuyoshi Muto ◽  
Hirokazu Miyata

The objective of this study is to clarify the deterioration behaviors of overlapping layers between Al-5Mg alloy thermal spray coating and heavy-duty paint coating. Combined cyclic corrosion tests were carried out on common carbon steel plates with overlapping layers. To evaluate the effective area of the sacrificial anode reaction caused by the thermal spray coating, machined straight-line defects with widths of 0.2, 6 and 12 mm were introduced in the overlapping layer. The experimental results indicated that the layers began to deteriorate from the lower part of the thermal spray coating along the defects. The deterioration of the thermal spray coating was accelerated by the sealing treatment. The blister area and height at the overlapping layer were significantly different depending on the sealing treatment.


2018 ◽  
Vol 284 ◽  
pp. 1151-1156
Author(s):  
Lenar N. Shafigullin ◽  
A.R. Ibragimov ◽  
A.I. Saifutdinov

C. C. Berndt advanced investigations of mechanical properties of thermal spray coatings under 4-point bending. He found that this investigation method is sensitive to the mechanical properties of thermal spray coatings.This paper contains the detailed investigation results for thermal spray coatings of zirconium dioxide under 4-point bending, i.e. tests of the specimens subjected to spraying at varying conditions and pre-test soaking with the various duration at 1100 °С.It was established how the mechanical properties of thermal spray coatings changed depending on the spraying mode and high temperature soaking. The test results show that the double heat treatment of coatings is more preferable than one-time heat treatment as it make the properties change linearly. It is more easily controllable during operation of the components with thermal spray coating.


Author(s):  
A. Scrivani ◽  
N. Antolotti ◽  
S. Bertini ◽  
G. Viola ◽  
R. Groppetti ◽  
...  

Abstract The paper discusses the testing methodology and identifies the analytical protocols, with proper validation, in order to evaluate the compatibility of thermal spray coatings in the food production technology, according to EU and FDA applicable standards. A brief state-of-the-art analysis of the international standards on food additives and human health is given, namely on indirect food additives (as defined in 21 CFR 170.3(e)), that can migrate into the food during the process. An outline of the test protocols, based on contact between coating and food simulating solvents in a set time/temperature conditions, are presented, and the main phases for the proposed testing methodology, as the choice of the simulating solvent, the migration cell design and the time/temperature conditions, are discussed. Finally the proposed methodology and protocols are validated through a thermal spray coating for food process application test case.


2007 ◽  
Vol 353-358 ◽  
pp. 2403-2406
Author(s):  
Koichi Taniguchi ◽  
Manabu Enoki ◽  
Koichi Tomita

AE method is a well-known technique for in-situ monitoring of damage behavior by attached piezoelectric transducer. However, this conventional detection of AE signals has certain limitations. In recent years, numerous efforts have addressed the substitution of laser-based techniques for ultrasonic nondestructive evaluation in place of conventional piezoelectric transducers. Especially, a laser interferometer can be used to measure a displacement or velocity at materials surface using Doppler-shift. However, there are few reports referring to the detection of AE signals in the practical materials and testing because of the difficulty of experiments. We developed the AE measurement system with laser interferometer to apply this technique to microcrack evaluation and reported the quantitative AE analysis in various materials. This paper demonstrates AE results from thermal spray coatings at elevated temperature.


2021 ◽  
Author(s):  
Nadimul Haque Faisal ◽  
Rehan Ahmed ◽  
Anil K Prathuru ◽  
Anna Paradowska ◽  
Tung Lik Lee

Abstract Background: During thermal spray coating, residual strain is formed within the coating and substrates due to thermo-mechanical processes and microstructural phase changes. Objective: This paper provides a comprehensive guide to researchers planning to use neutron diffraction technique for thermal spray coatings, and reviews some of these studies. Methods: ENGIN-X at the ISIS spallation source is a neutron diffractometer (time-of-flight) dedicated to materials science and engineering with high resolution testing. The focus is on the procedure of using ENGIN-X diffractometer for thermal spray coatings with a view that it can potentially be translated to other diffractometers. Results: Number of studies involving neutron diffraction analysis in thermal spray coatings remain limited, partly due to limited number of such strain measurement facilities globally, and partly due to difficulty is applying neutron diffraction analysis to measure residual strain in the thermal spray coating microstructure. Conclusions: This technique can provide a non-destructive through-thickness residual strain analysis in thermally sprayed components with a level of detail not normally achievable by other techniques. Neutron sources have been used to measure strains in thermal spray coatings, and here, we present examples where such coatings have been characterised at various neutron sources worldwide, to study residual strains and microstructures.


2020 ◽  
Vol 901 ◽  
pp. 49-54
Author(s):  
Jirasak Tharajak ◽  
Noppakun Sanpo

Thermal spraying is a technology which improves and restores the surface of a solid material. The process can be used to apply coatings to a wide range of materials and components, in order to provide resistance to wear, erosion, cavitation, corrosion, abrasion or heat. In this paper, the study of abrasive and erosive properties of Cr3C2/20%NiCr and FeCrB + Al thermal sprayed coating samples were focused. It was revealed that both received thermal spray coating samples show outstanding abrasive and erosive resistance properties.


Author(s):  
L. Dekhtyar ◽  
A. Kleyman ◽  
S. Berman ◽  
V. Andreychuk

Abstract Future development of thermal spray processes and new composite materials raises an important problem concerning the transition from qualitative to quantitative methods of coatings evaluation. It is well known that thermal spray coating deposition in most cases is accompanied by the formation of temporal and residual stresses through the coating thickness. For proper evaluation of formed stressed state it is extremely important to know the real value of elastic characteristics in different layers of the coating. This problem has become more complicated taking into consideration the variety of materials, different spray parameters, number of coating layers and extreme service conditions. These values can be obtained only from experimentation. Elastic characteristics (EC) could be used in many calculations, such as durability, stiffness, fatigue, vibration and others. This paper describes new methods of experimental determination of elastic characteristics presumed as variable throughout the coating thickness. Influence of coating composition, particle size of initial powders, spray parameters, post-treatment and other factors on elastic modulusses were studied. Obtained experimental data for different materials supplement existing data and can be used for evaluation of residual stresses and other purposes.


Author(s):  
C Bartuli ◽  
T Valente ◽  
F Casadei ◽  
M Tului

Thermal spray coating is one of the most common procedures to improve the tribological properties of materials. Ceramic and cermet coatings, especially those based on oxides (alumina, chromium oxide, etc.) and carbides, are widely used for wear protection. Improvements under investigations are related to the possible use of nanostructured coatings and to the potential application of hybrid techniques. As a possible alternative, solid lubrication is proposed as integration or replacement of the traditional liquid lubrication in the case of severe operative conditions when there is the possibility of a lack of lubricant or when environmental problems can arise from waste disposal. In the present paper, results from experimental activities on different types of abrasion-resistant thermal spray coatings are presented: graded coating systems, specifically designed for titanium-based alloys, obtained by reactive plasma spraying and physical vapour deposition of titanium nitrides; nanostructured WC-Co coatings deposited by high velocity oxy-fuel; plasma-sprayed ceramic coatings based on oxides containing nanophases either from nanostructured precursors or postprecipitated by purposely designed thermal treatments; self-lubricant coatings deposited by plasma spray with the inclusion of graphite.


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