Sealing of thermal spray coatings by impregnation

Abstract

Results from the sealing of porosity by impregnation show that below a certain wetting angle of the sealant, high penetration depths are achieved. However, only sealants with very low curing shrinkages can prevent the transport of electrolyte through the coating.Various sealant types and impregnation methods are discussed, and factors influencing impregnation and sealing ability of sealants are reviewed. Experimental results from the sealing of plasma-sprayed aluminum-oxide coatings are presented.

Thermal Sprayed Coatings Used Against Corrosion and Corrosive Wear

“…However it must be kept in mind that such post-treatments increase more or less the cost of the coating. Knuuttila et al (1999) gave a description of the sealing process presenting various sealant types and impregnation methods, as well as the factors influencing impregnation. Impregnation methods can be divided into four categories: atmospheric pressure impregnation, low-pressure impregnation, overpressure impregnation, and a combination of the previous methods.…”

Effect of Sealing Materials and Parameters on the Corrosion Resistance of HVOF-Sprayed CrC-NiCr Coatings

“…또한 인산, 페놀 및 에폭시 계열의 실링재를 플라즈마 용사된 Al 2 O 3 -13%TiO 2 코팅에 적용한 결과, 페놀과 에폭시 계열 의 실링재가 인산보다 우수한 실링특성을 보인 결 과도 보고된 바 있다 15) . 지금까지의 연구결과를 종합해 보면 실링재의 종 류에 따른 침투깊이를 관찰하여 코팅의 내식성에 미치는 영향, 또는 실링처리가 코팅의 경도 9,14) , 내 마모성 9,11,18) , 밀착력 9,11,19) , 표면 거칠기 …”

Electrochemical Characterisations of Al2O3–13%TiO2 Coated by Atmospheric Plasma Spray

“…Because of their lamellar structure, coatings are characterized by a relatively high open porosity and incomplete bonding between lamellae, which are deleterious when the coatings have to perform in an aggressive environment. The porosity allows a path for electrolytic solutions from the outer surface to the substrate [6][7][8].…”