Improving wear and corrosion resistance of thermal sprayed coatings

Abstract

Thermal sprayed coatings are used in various applications often dedicated to corrosion and wear protection.Poresand other coating imperfections reduce corrosion and wear resistance and/or necessitate higher coating thicknesses. To improve the quality of thermal sprayed coatings, various post-treatment processes can be used. Characterisation of the efficiency of sealing was studied by metallographic examination andcomparative investigation of the corrosion and wear behaviour of the thermal sprayed coatings used with and without sealing and also by measuring the insulation resistance of the coating system. The results differ among the sealants. It is possible to remove the sealants from the coatings by mechanical treatment. Corrosion tests of the sealants demonstrate their efficiency in closing the interconnected pores and, consequently, preventing corrosion.

Mechanical and metallurgical properties of plasma sprayed and laser remelted Ni–20Cr and Stellite-6 coatings

“…Moreover, other favourable properties can be produced at the coating or component surface. As a result, these coatings have found use in various industrial applications [6].…”

Sealing of thermal spray coatings by impregnation

“…Few detailed publications exist about sealing of thermal spray coatings by organic sealants ( Ref 11,12). In many publications, the information about sealants or experimental procedure is inadequate.…”

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 …”