Flame Spraying of Polymers

1997 ◽  
Author(s):  
D.J. Varacalle ◽  
D.P. Zeek ◽  
K.W. Couch ◽  
D.M. Benson ◽  
S.M. Kirk
Keyword(s):  
Thermal Spraying ◽  
Statistical Design ◽  
Compositional Analysis ◽  
Deposition Efficiency ◽  
Polymer Coatings ◽  
Fractional Factorial ◽  
Flame Spraying ◽  
Knoop Microhardness ◽  
Coating Design ◽  
A Site

Abstract Statistical design-of-experiment studies of the thermal spraying of polymer powders are presented. Studies of the subsonic combustion (i.e., Flame) process were conducted in order to determine the quality and economics of polyester and urethane coatings. Thermally sprayed polymer coatings are of interest to several industries for anticorrosion applications, including the chemical, automotive, and aircraft industries. In this study, the coating design has been optimized for a site-specific application using Taguchi-type fractional-factorial experiments. Optimized coating designs are presented for the two powder systems. A substantial range of thermal processing conditions and their effect on the resultant polymer coatings is presented. The coatings were characterized by optical metallography, hardness testing, tensile testing, and compositional analysis. Characterization of the coatings yielded the thickness, bond strength, Knoop microhardness, roughness, deposition efficiency, and porosity. Confirmation testing was accomplished to verify the coating designs.

Studies of the Flame Spraying of Polymers

1996 ◽  
Author(s):  
D.J. Varacalle ◽  
K.W. Couch ◽  
V.S. Budinger
Keyword(s):  
Bond Strength ◽  
Combustion Process ◽  
Experimental Studies ◽  
Polymer Coatings ◽  
Flame Spraying ◽  
Knoop Microhardness ◽  
Resultant Coating ◽  
Strength Characterization ◽  
Thermally Sprayed

Abstract Experimental studies of the subsonic combustion process have been conducted in order to determine the quality and economics of polyester, epoxy, urethane, and hybrid polyester-epoxy coatings. Thermally sprayed polymer coatings are of interest to several industries for anti-corrosion applications, including the infrastructural, chemical, automotive, and aircraft industries. Classical experiments were conducted, from which a substantial range of thermal processing conditions and their effect on the resultant coating were obtained. The coatings were characterized and evaluated by a number of techniques, including Knoop microhardness tests, optical metallography, image analysis, and bond strength. Characterization of the coatings yielded thickness, bond strength, hardness, and porosity.

Influence of a Filler Composition and Conditions of Flame Spraying on a Structure and Mechanical Properties of Composite Polymer Coatings

1997 ◽  
Author(s):  
Yu. Borisov ◽  
V. Korzhik ◽  
I. Sviridova ◽  
A. Skorokhod
Keyword(s):  
Mechanical Properties ◽  
Thermal Spraying ◽  
Polymer Coatings ◽  
Flame Spraying ◽  
Composite Polymer ◽  
Filled Polymers ◽  
Physico Chemical ◽  
Mechanical And Service Properties ◽  
Sprayed Coatings ◽  
Thermal Sprayed Coatings

Abstract In thermal spraying of metal-polymer coatings, the processes of polymers oxidation and destruction can have special features, as the temperature of heating of the filler particles can significantly exceed the temperature of destruction of the polymer binder. Hence, the need to study the features of the process of formation of thermal sprayed coatings from filled polymers and their physico-chemical, mechanical and service properties. This paper describes the influence of a filler composition and conditions of flame spraying on a structure and mechanical properties of composite polymer coatings. It is observed that addition of 5-10 vol. % of Fe-Ni-B alloy powder to low-pressure polyethylene polymer matrices, improves the wear resistance of thermal sprayed coatings 1.2-1.3 times under the conditions of gas-abrasive wear, compared to purely polymer coating, owing to the combination of the higher hardness of the coating with the high damping properties of the polymer matrix.

scholarly journals Modeling and Optimization in Investigating Thermally Sprayed Ni-Based Self-Fluxing Alloy Coatings: A Review

Materials ◽  
2020 ◽  
Vol 13 (20) ◽  
pp. 4584
Author(s):  
Katica Simunovic ◽  
Sara Havrlisan ◽  
Tomislav Saric ◽  
Djordje Vukelic
Keyword(s):  
Statistical Methods ◽  
Design Of Experiment ◽  
Thermal Spraying ◽  
Statistical Design ◽  
Flame Spraying ◽  
Modeling And Optimization ◽  
Designed Experiments ◽  
Input Variables ◽  
Correct Application ◽  
Thermally Sprayed

In investigating thermally sprayed Ni-based self-fluxing alloy coatings, widely applied under conditions of wear, corrosion, and high temperatures, designed experiments and statistical methods as a basis for modeling and optimization have become an important tool in making valid and comparable conclusions. Therefore, this paper gives an overview of investigating Ni-based self-fluxing alloy coatings deposited by thermal spraying by the use of designed experiments and statistical methods. The investigation includes the period of the last two decades and covers the treatments of flame spraying, high-velocity oxy/air fuel spraying, plasma spraying, plasma-transferred arc welding, and laser cladding. The main aim was to separate input variables, as well as measured responses, and to point out the importance of correct application of statistical design of experiment. After the review of the papers, it was concluded that investigators have used the process knowledge to analyze and interpret the results of the statistical analysis of experimental data, which is in fact the best way of using the design of experiment in every research. Nevertheless, more attention should be given to correct planning and conducting the experiments to derive the models suitable for the prediction of measured response and which could be an appropriate input for single- or multi-objective optimization.

Effects of Gun Nozzle Geometry on High Velocity Oxygen-Fuel (HVOF) Thermal Spraying Process

1998 ◽  
Author(s):  
K. Sakaki ◽  
Y. Shimizu ◽  
Y. Gouda ◽  
A. Devasenapathi
Keyword(s):  
Numerical Simulation ◽  
Experimental Studies ◽  
Thermal Spraying ◽  
Deposition Efficiency ◽  
Divergence Angle ◽  
Nozzle Geometry ◽  
Oxide Content ◽  
Hvof Thermal Spraying ◽  
Throat Diameter ◽  
Spraying Process

Abstract Effect of nozzle geometry (such as throat diameter of a barrel nozzle, exit diameter and exit divergence angle of a divergent nozzle) on HVOF thermal spraying process (thermodynamical behavior of combustion gas and spray particles) was investigated by numerical simulation and experiments with Jet KoteTM II system. The process changes inside the nozzle as obtained by numerical simulation studies were related to the coating properties. A NiCrAIY alloy powder was used for the experimental studies. While the throat diameter of the barrel nozzle was found to have only a slight effect on the microstructure, hardness, oxygen content and deposition efficiency of the coatings, the change in divergent section length (rather than exit diameter and exit divergence angle) had a significant effect. With increase in divergent section length of the nozzle, the amount of oxide content of the NiCrAIY coatings decreased and the deposition efficiency increased significantly. Also, with increase in the exit diameter of the divergent nozzle, the gas temperature and the degree of melting of the particle decreased. On the other hand the calculated particle velocity showed a slight increase while the gas velocity increased significantly.

Comparison between Tribological Characteristics of Al-Cu-Fe-B Quasicrystalline and Mo Coatings

2007 ◽  
Vol 26-28 ◽  
pp. 715-718
Author(s):  
Bong Hwan Kim ◽  
Sang Mok Lee
Keyword(s):  
Mechanical Properties ◽  
Surface Energy ◽  
Bonding Strength ◽  
Tribological Behavior ◽  
Thermal Spraying ◽  
Microstructural Characterization ◽  
Flame Spraying ◽  
Energy Calculation ◽  
Air Plasma ◽  
Oxygen Fuel

Al-Cu-Fe-B quasicrystalline and Mo coatings were obtained on the mild steel and brass substrates by thermal spraying routes for the purpose of replacement of Mo coatings with quasicrystalline ones. Quasicrystalline coatings were prepared by air plasma spraying and/or HVOF (High Velocity Oxygen Fuel) techniques followed by subsequent heat treatment, and Mo coatings, wire flame spraying. For comparative studies of important properties for industrial application, mechanical properties, bonding strength, surface energy, and tribological behavior were investigated based on microstructural characterization. Basic mechanical properties such as hardness, fracture toughness, and elastic modulus of quasicrystalline coating showed comparable values with those of Mo coatings. De-bonding tests of coatings deposited onto brass substrate indicated that the bonding strength of quasicrystalline coatings obtained by HVOF techniques exhibit higher value to Mo coatings. Non-sticking property analogized from surface energy calculation and friction coefficient of quasicrystalline coatings also showed better performance during the tests. It is suggested from this investigation that the quasicrystalline coating can be effectively used as a replacement of the Mo coating, which has shown a recent steep price rise and problems of accidental existence of minor environment harmful elements such as Cr6+, Pb, Cd, and Hg.

Thermally Sprayed Ternary Materials for Enhanced Corrosion Protection

1997 ◽  
Author(s):  
T. Lester ◽  
S.J. Harris ◽  
D. Kingerley ◽  
S. Matthews
Keyword(s):  
Barrier Layer ◽  
Salt Spray ◽  
Thermal Spraying ◽  
Steel Structures ◽  
Deposition Efficiency ◽  
Aqueous Corrosion ◽  
Metal Coatings ◽  
Zinc Coatings ◽  
Thermally Sprayed ◽  
Better Than

Abstract Thermal spraying has been used to protect many steel structures from aqueous corrosion using Zinc and Aluminium, and to some extent their alloy coatings to provide galvanic protection. The lifetimes of the coatings can approach 50 years even when exposed in severe marine environments. Zinc coatings work by continuously sacrificing themselves and slowly dissipating over time. Aluminium coatings passivate more readily and form a barrier layer, the passivity makes them less able to protect damaged areas and to self heal. A new ternary coating system involving Aluminium, Zinc and Magnesium has been shown to be capable of providing both a passive barrier layer as well as being able to give galvanically active protection. Salt spray tests have shown that the resistance to red rust of these new coatings increases by 300% over similar thicknesses of the separate metal coatings. Processing by arcspray is straightforward and both adhesion and deposition efficiency are better than where Zinc is sprayed alone.

Statistical Optimization of HVAF Sprayed Cr3C2-NiCr Coatings for Minimizing Decarburization

2000 ◽  
Author(s):  
S.J. Matthews ◽  
M.M. Hyland
Keyword(s):  
Factorial Design ◽  
Statistical Design ◽  
Process Variable ◽  
Traverse Speed ◽  
Deposition Efficiency ◽  
Spray Parameters ◽  
Statistical Design Of Experiments ◽  
Spray Coatings ◽  
Wide Range ◽  
Statistical Designs

Abstract High-velocity air fuel (HVAF) spraying was selected for spray trials of a Cr3C2-NiCr powder. To determine the effect of spray parameters on coating characteristics, particularly porosity and phase degradation, a statistical design of experiments was implemented. A wide range of statistical designs have been applied to the optimization of thermal spray coatings with a great deal of success. In this instance, a lack of prior knowledge and the need to assess many process-variable interactions efficiently led to the selection of a two-level full factorial design. High and low settings for each variable, including spray distance, traverse speed, and powder feedrate, were chosen based on the ranges typically used to spray similar materials. The resulting coatings were assessed for microhardness, porosity, residual stress, deposition efficiency, and phase transformation, after which several follow-up runs were conducted to explore trends brought to light by the initial factorial design.

Varying of Oil Consumption of Fluid-Film Bearing’s Surface Layer by Means of Application of Anti-Friction Coatings

2018 ◽  
Vol 284 ◽  
pp. 1263-1267
Author(s):  
Alexey Yu. Rodichev ◽  
A.V. Sytin ◽  
V.O. Tyurin
Keyword(s):  
Surface Layer ◽  
Steel Substrate ◽  
Thermal Spraying ◽  
Fluid Film ◽  
Flame Spraying ◽  
Oil Consumption ◽  
Fluid Film Bearings ◽  
Inner Surface ◽  
Accessible Method ◽  
Gas Flame

Gas flame spraying is the most accessible method of gas-thermal spraying. Pores are formed on the inner surface of the bimetallic fluid-film bearings as a result of the application of anti-friction coating on the steel substrate. The presence of such pores, the "microfibre effect", affects positively on life expectancy of fluid-film bearings. The study of the oil consumption of anti-friction coatings allows recommendation of these coatings for using in the manufacturing process of bimetallic fluid-film bearings.

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