Thermal spraying. Determination of the deposition efficiency for thermal spraying

2018 ◽  
Keyword(s):  
Thermal Spraying ◽  
Deposition Efficiency

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.

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.

scholarly journals ASSESSMENT TRIBOLOGICAL PROPERTIES OF COATINGS APPLIED BY HVOF TECHNOLOGY

2013 ◽  
Vol 7 (3) ◽  
pp. 135-139 ◽  
Author(s):  
Janette Brezinová ◽  
Anna Guzanová ◽  
Dagmar Draganovská ◽  
Marián Egri
Keyword(s):  
Room Temperature ◽  
Adhesive Wear ◽  
Thermal Spraying ◽  
Basic Material ◽  
High Velocity Oxygen Fuel ◽  
Properties Of Coatings ◽  
Oxygen Fuel ◽  
Spraying Method

Abstract In this article, the attention is paid to the HVOF (High Velocity Oxygen Fuel) thermal spraying method by which the progressive coatings are applied on basic material C15E (STN 412020). These coatings are based on C-17CO, WC-CO-Cr and Cr3C2-25NiCr. There was made determination of the chemical composition of the coatings and assessment of coatings quality - adhesion, microhardness, porosity and wear resistance at room temperature (21°C) and also at operational elevated temperature (900°C). Results of adhesive wear showed high quality of all evaluated coatings and their suitability to extreme tribological conditions.

scholarly journals Determination of the effective porosity of a single filter fiber

2021 ◽  
Vol 2094 (2) ◽  
pp. 022075
Author(s):  
V Soloveva ◽  
S A Solovev ◽  
S I Kharchuk ◽  
L A Belousova ◽  
A R Talipova
Keyword(s):  
Deposition Efficiency ◽  
Effective Porosity ◽  
Ansys Software ◽  
Fixed Size ◽  
Fiber Model ◽  
Porous Filter ◽  
Random Arrangement ◽  
Inert Particles ◽  
Medium Porosity

Abstract In this work, a numerical simulation of the aerosol motion when flowing around a single porous filter fiber with a diameter of 5 mm is carried out. The fiber is formed by a set of microfibers in a random arrangement. The size of the microfibers varies from 0.1 mm to 0.5 mm. For each fixed size of microfibers, a fiber model with different porosity of the medium was created. The porosity ranged from 0.7 to 0.9. The calculations were carried out in the ANSYS software package (v. 19.0). Studies have shown that a porous filter fiber model provides the maximum deposition efficiency for highly inert particles is provided by a porous filter fiber model with a microfiber size of 0.1 mm and a medium porosity of 0.9.

Effect of Shot Peening and NiAl Coating on Fatigue Limit of Mg-Al-Zn-Mn Alloy

2011 ◽  
Vol 56 (3) ◽  
pp. 743-748 ◽  
Author(s):  
P. Mrva ◽  
D. Kottfer ◽  
Ł. Kaczmarek
Keyword(s):  
Fatigue Limit ◽  
Shot Peening ◽  
Thermal Spraying ◽  
Analytical Determination ◽  
Standard Measurement

Effect of Shot Peening and NiAl Coating on Fatigue Limit of Mg-Al-Zn-Mn Alloy The paper deals with an influence of cylic load on fatigue limit of the Mg-Al-Zn-Mn alloy without or with the NiAl coating. The fatigue limit was determined for the following three types of specimens of the Mg-Al-Zn-Mn alloy: (1) fine-turned specimens; (2) fine-turned specimens with an application of the shot peening process; (3) fine-turned and shot-peened specimens with the NiAl coating deposited by the thermal spraying technique. A standard measurement of the fatigue limit was used for the analytical determination of the Wohler curves (S-N curves). The Wohler curves for the specimens (1) and (3) were in agreement with those presented in literature. The specimens (2) exhibited a lower value of the fatigue limit compared with that of the specimens (1), although the increase of the fatigue limit of the specimens (2) was expected due to the presence of the application of the shot peening process. An analysis of reasons of the decrease of the fatigue limit of the specimens (2) is presented.

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