The effect of roughness and pre-heating of the substrate on the morphology of aluminium coatings deposited by thermal spraying

Paredes, Ramón Sigifredo Cortés; Amico, Sandro Campos; D'Oliveira, Ana Sofia

doi:10.1016/j.surfcoat.2005.02.200

Cited by 151 publications

(66 citation statements)

References 5 publications

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“…The top surface and cross section morphology of the coating by the SEM are shown in Figure 3. This coating had many defects as shown by the arrow marks (Figure 3a,b), which is a well-known feature for such coatings [6,8]. The melted metal particles continuously impinged on the base metals and formed layer upon layer of plate-like microstructures [26].…”

Section: Characterization Of the Arc Thermal Sprayed Coatingsmentioning

confidence: 92%

Corrosion Resistance Properties of Aluminum Coating Applied by Arc Thermal Metal Spray in SAE J2334 Solution with Exposure Periods

Lee

Singh

Ismail

et al. 2016

Metals

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Arc thermal metal spray coating provides excellent corrosion, erosion and wear resistance to steel substrates. This paper incorporates some results of aluminum coating applied by this method on plain carbon steel. Thereafter, coated panels were exposed to an environment known to form stable corrosion products with aluminum. The coated panels were immersed in Society of Automotive Engineers (SAE) J2334 for different periods of time. This solution consists of an aqueous solution of NaCl, CaCl 2 and NaHCO 3 . Various electrochemical techniques, i.e., corrosion potential-time, electrochemical impedance spectroscopy (EIS) and the potentiodynamic were used to determine the performance of stimulants in improving the properties of the coating. EIS studies revealed the kinetics and mechanism of corrosion and potentiodynamic attributed the formation of a passive film, which stifles the penetration of aggressive ions towards the substrate. The corrosion products that formed on the coating surface, identified using Raman spectroscopy, were Dawsonite (NaAlCO 3 (OH) 2 ) and Al(OH) 3 . These compounds of aluminum are very sparingly soluble in aqueous solution and protect the substrate from pitting and uniform corrosion. The morphology and composition of corrosion products determined by scanning electron microscopy and energy dispersive X-ray analyses indicated that the environment plays a decisive role in improving the corrosion resistance of aluminum coating.

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Section: Characterization Of the Arc Thermal Sprayed Coatingsmentioning

confidence: 92%

Corrosion Resistance Properties of Aluminum Coating Applied by Arc Thermal Metal Spray in SAE J2334 Solution with Exposure Periods

Lee

Singh

Ismail

et al. 2016

Metals

View full text Add to dashboard Cite

show abstract

“…In general, higher substrate roughness leads to higher adhesion [11][12][13]; this has been observed both for the deposition of fully molten (plasma sprayed) and semi-molten (HVOF-sprayed) particles [14]. However, for higher roughness range (>50 µm), adhesion was also found to decrease with increasing roughness [15]. The interlocking is most effective under the center of the splat, where the pressure upon impact is highest, and decreases towards the splat periphery [10].…”

Section: Introductionmentioning

confidence: 96%

“…The presence of oxides or hydroxides at the interface might inhibit the contact between the two materials; if these are thin enough, however, localized substrate melting, jetting and interdiffusion are still possible [22]. Preheating appears to improve the wettability of the substrate by the particles, thereby enhancing the adhesion, even in cases of splashing [15]. Rough substrates often lead to splats with higher thickness and lower diameter [10], while their splashing is suppressed [23].…”

Section: Introductionmentioning

confidence: 99%

The Influence of Interface Characteristics on the Adhesion/Cohesion of Plasma Sprayed Tungsten Coatings

et al. 2013

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Abstract:Tungsten is the prime candidate material for plasma facing components of future fusion devices. Plasma spraying, with its ability to coat large areas, including non-planar surfaces, with a significant thickness, is a prospective fabrication technology for components subject to moderate heat loads, e.g., the first wall of the Demonstration Reactor (DEMO). The functionality of such coatings is critically dependent on their adhesion to the underlying material. This in turn, is influenced by a variety of processing-related factors, chief among them being the state of the interface. In this study, the effects of two factors-surface roughness and the presence of thin interlayers-were investigated. Two different levels of roughness of steel substrates were induced by grit blasting, and two thin interlayers-titanium (Ti) and tungsten (W)-were applied by physical vapor deposition prior to plasma spraying of W by a Water Stabilized Plasma (WSP) torch. Coating adhesion was determined by a shear adhesion test. The structures of the coatings and the interfaces, as well as the characteristics of the fractured surfaces, were observed by SEM.

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“…Thus, the water impermeability of the metal spray coating is an important factor. However, because a metal spray forms a film from stacking solid metal particles on the concrete in powder form, many pores exist between particles and on the surface [22][23][24][25][26]. Thus, different surface treatments were performed on the metal spray coating, and their effects on the water impermeability were evaluated.…”

Section: Introductionmentioning

confidence: 99%

Ozone Resistance, Water Permeability, and Concrete Adhesion of Metallic Films Sprayed on a Concrete Structure for Advanced Water Purification

2017

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Abstract:We evaluated the applicability of metal spray coating as a waterproofing/corrosion protection method for a concrete structure used for water purification. We carried out an ozone resistance test on four metal sprays and evaluated the water permeability and bond strength of the metals with superior ozone resistance, depending on the surface treatment method. In the ozone resistance test, four metal sprays and an existing ozone-proof paint were considered. In the experiment on the water permeability and bond strength depending on the surface treatment method, the methods of no treatment, surface polishing, and two types of pore sealing agents were considered. The results showed that the sprayed titanium had the best ozone resistance. Applying a pore sealing agent provided the best adhesion performance, of about 3.2 MPa. Applying a pore sealing agent also provided the best waterproofing performance. Scanning electron microscope analysis showed that applying a pore sealing agent resulted in an excellent waterproofing performance because a coating film formed on top of the metal spray coating. Thus, when using a metal spray as waterproofing/corrosion protection for a water treatment concrete structure, applying a pore sealing agent on top of a film formed by spraying titanium was concluded to be the most appropriate method.

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The effect of roughness and pre-heating of the substrate on the morphology of aluminium coatings deposited by thermal spraying

Cited by 151 publications

References 5 publications

Corrosion Resistance Properties of Aluminum Coating Applied by Arc Thermal Metal Spray in SAE J2334 Solution with Exposure Periods

Corrosion Resistance Properties of Aluminum Coating Applied by Arc Thermal Metal Spray in SAE J2334 Solution with Exposure Periods

The Influence of Interface Characteristics on the Adhesion/Cohesion of Plasma Sprayed Tungsten Coatings

Ozone Resistance, Water Permeability, and Concrete Adhesion of Metallic Films Sprayed on a Concrete Structure for Advanced Water Purification

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