Elasticity Characteristics of Plasma Spray Coatings

1996 ◽  
Author(s):  
L. Dekhtyar ◽  
A. Kleyman ◽  
S. Berman ◽  
V. Andreychuk
Keyword(s):  
Residual Stresses ◽  
Thermal Spray ◽  
Coating Thickness ◽  
Quantitative Methods ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Spray Parameters ◽  
Spray Coatings ◽  
Real Value ◽  
Elastic Characteristics

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.

Effects of coating thickness and residual stresses on the bond strength of ASTM C633-79 thermal spray coating test specimens

1994 ◽  
Vol 3 (4) ◽  
pp. 371-378 ◽  
Author(s):  
D. J. Greving ◽  
J. R. Shadley ◽  
E. F. Rybicki ◽  
D. J. Greving ◽  
J. R. Shadley ◽  
...  
Keyword(s):  
Residual Stresses ◽  
Bond Strength ◽  
Thermal Spray ◽  
Coating Thickness ◽  
Spray Coating ◽  
Thermal Spray Coating

Investigation into the Effects of High Temperature on Mechanical Properties of Thermal Spray Coatings Applied by Plasma Spraying

2018 ◽  
Vol 284 ◽  
pp. 1151-1156
Author(s):  
Lenar N. Shafigullin ◽  
A.R. Ibragimov ◽  
A.I. Saifutdinov
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
High Temperature ◽  
Thermal Spray ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Thermal Spray Coatings ◽  
Spray Coatings ◽  
Heat Treatment Of Coatings ◽  
Double Heat Treatment

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.

A Contribution to Methodology and Protocol Definition for Thermal Spray Coated Surface Compatibility Analysis in Food Processing Applications

1998 ◽  
Author(s):  
A. Scrivani ◽  
N. Antolotti ◽  
S. Bertini ◽  
G. Viola ◽  
R. Groppetti ◽  
...  
Keyword(s):  
Thermal Spray ◽  
Food Additives ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
International Standards ◽  
Test Case ◽  
Testing Methodology ◽  
Spray Coatings ◽  
Temperature Conditions ◽  
Compatibility Analysis

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.

THE EFFECT OF COATING THICKNESS ON FATIGUE PROPERTIES OF STEEL THERMALLY SPRAYED WITH Ni-BASED SELF-FLUXING ALLOY

2006 ◽  
Vol 20 (25n27) ◽  
pp. 3599-3604 ◽  
Author(s):  
HIROYUKI AKEBONO ◽  
JUN KOMOTORI ◽  
HIDETO SUZUKI
Keyword(s):  
Fatigue Strength ◽  
Thermal Spray ◽  
Coating Thickness ◽  
Volume Fraction ◽  
Steel Substrate ◽  
Fatigue Cracks ◽  
Spray Coating ◽  
Maximum Size ◽  
Thermal Spray Coating ◽  
Fatigue Properties

The Thermal spraying is one of the most popular surface coating techniques. To achieve the most efficient use of this technique in practice, it is very important to clarify the fatigue properties of steel coated with a thermal spray coating. In this study, to clarify the effects of coating thickness on the fatigue properties of the steel substrate, three types of sprayed specimens with different coating thickness (0.2, 0.5 and 1.0mm) were prepared and fatigue tests were carried out. Coating thickness strongly affected the fatigue properties; the thinner the coating thickness, the higher the fatigue strength. Fatigue crack propagation behaviors were observed. Accordingly the fatigue cracks propagated through many defects on the coated surface. The sizes and number of the coating defects were determined by coating thickness; the thicker the coating thickness, the larger the defect and number. Therefore, the sprayed specimens with thinner coatings indicated higher fatigue strength. Furthermore, estimations of the fatigue strength were performed by using Murakami's equation. The fatigue strengths of thermal spray coated specimens were estimated by three parameters; (i) maximum size of coating defects estimated by statistics of extreme value, (ii) hardness of the matrix and (iii) volume fraction of coating defects.

In-Process Damage Monitoring and Stress Analysis of Thermal Spray Coating

2007 ◽  
Vol 353-358 ◽  
pp. 2403-2406
Author(s):  
Koichi Taniguchi ◽  
Manabu Enoki ◽  
Koichi Tomita
Keyword(s):  
Thermal Spray ◽  
Laser Interferometer ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
In Situ Monitoring ◽  
Spray Coatings ◽  
Damage Monitoring ◽  
Process Damage ◽  
Ae Signals

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.

scholarly journals Measuring residual strain and stress in thermal spray coatings using neutron diffractometers

2021 ◽  
Author(s):  
Nadimul Haque Faisal ◽  
Rehan Ahmed ◽  
Anil K Prathuru ◽  
Anna Paradowska ◽  
Tung Lik Lee
Keyword(s):  
Neutron Diffraction ◽  
Diffraction Analysis ◽  
Thermal Spray ◽  
Residual Strain ◽  
Spray Coating ◽  
Thermal Spray Coating ◽  
Thermal Spray Coatings ◽  
Neutron Sources ◽  
Neutron Diffraction Analysis ◽  
Spray Coatings

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.

The Comparison Study on Abrasive and Erosive Resistance Properties of Thermal Spray Coatings

2020 ◽  
Vol 901 ◽  
pp. 49-54
Author(s):  
Jirasak Tharajak ◽  
Noppakun Sanpo
Keyword(s):  
Thermal Spray ◽  
Thermal Spraying ◽  
Spray Coating ◽  
Solid Material ◽  
Thermal Spray Coating ◽  
Comparison Study ◽  
Spray Coatings ◽  
Wide Range ◽  
Resistance To Wear ◽  
Sprayed Coating

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.

Methods of Determination and Control of Residual Stresses in Plasma Spray Coatings

1997 ◽  
Author(s):  
L. Dekhtyar ◽  
A. Kleyman ◽  
V. Andreychuk ◽  
S. Berman
Keyword(s):  
Residual Stresses ◽  
Thermal Spray ◽  
Plasma Spray ◽  
Thermal Spraying ◽  
Thermal Spray Coatings ◽  
Coating Deposition ◽  
Spray Coatings ◽  
Plasma Spray Coatings ◽  
And Control ◽  
Elastic Characteristics

Abstract Residual stresses exert profound influence on the longevity of parts with thermal spray coatings. The distribution and value of the residual stresses depend on method of coating deposition, composition of the applied material, parameters of thermal spraying and methods of post-treatment. Therefore, the study of the influence of the various technological factors on the residual stresses in the plasma spray coatings is very important. Due to heterogeneity of the coating, residual stresses can be determined only by the experimentation by using new methods which take into consideration real values of elastic characteristics and density of elementary layers. Methods and formulas for the calculations of the residual stresses in coatings deposited on bars, rings, discs, cylinders are presented. Experimental results for the various thermal spray coatings are also shown. These results can be used for the optimization of coating deposition and would supplement the existing database.

Advanced thermal spray coatings for tribological applications

2007 ◽  
Vol 221 (3) ◽  
pp. 175-185 ◽  
Author(s):  
C Bartuli ◽  
T Valente ◽  
F Casadei ◽  
M Tului
Keyword(s):  
Thermal Spray ◽  
Spray Coating ◽  
Ceramic Coatings ◽  
Thermal Spray Coating ◽  
Thermal Spray Coatings ◽  
Solid Lubrication ◽  
Titanium Nitrides ◽  
Spray Coatings ◽  
Hybrid Techniques ◽  
Wear Protection

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.

COATING LAYER AND CORROSION PROTECTION CHARACTERISTICS IN SEA WATER WITH VARIOUS THERMAL SPRAY COATING MATERIALS FOR STS304

2010 ◽  
Vol 17 (03) ◽  
pp. 299-305 ◽  
Author(s):  
SEONG-JONG KIM ◽  
YONG-BIN WOO
Keyword(s):  
Thermal Spray ◽  
Sea Water ◽  
Coating Layer ◽  
Spray Coating ◽  
Corrosion Current ◽  
Thermal Spray Coating ◽  
Coating Materials ◽  
Optimal Method ◽  
Spray Coatings ◽  
Coating Methods

We investigated the optimal method of application and the anticorrosive abilities of Zn , Al , and Zn + 15%Al spray coatings in protecting stainless steel 304 (STS304) in sea water. If a defect such as porosity or an oxide layer, causes STS304 to be exposed to sea water, and the thermal spray coating material will act as the cathode and anode, respectively. The Tafel experiments revealed that Al -coated specimens among applied coating methods had the lowest corrosion current densities. As the corrosion potential decreases with increasing corrosion current density, we estimated the characteristics and lifetime of the protective thermal spray coating layer in the galvanic cell formed by the thermal spray coating layer and STS304.

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