| Title |
Research Paper / Surface Treatment : Electrical Insulation Properties of the Plasma Sprayed Ceramic Coatings |
| Authors |
김형준(Hyung Jun Kim); (Sidoine Odoul); 이창희(Chang Hee Lee); 권영각(Young Gak Kweon) |
| ISSN |
1738-8228(ISSN), 2288-8241(eISSN) |
| Abstract |
Electrical insulation behavior of the plasma-sprayed ceramic coatings was investigated by measuring the electrical resistivity and the dielectric breakdown voltage. As a post-treatment of the coatings, sealing treatment was carried out. The penetration depth of the sealants to the ceramic coating was investigated by using fluorescent dye method and its effects on the electrical insulation properties. Electrical resistivity of the alumina based coatings was measured up to 10^(15)Ω·㎝, which was close to that (10^(16)Ω·㎝) of the sintered alumina, but decreased as the content of the TiO₂ is increased. It is considered that the mechanism of dielectric breakdown voltage of the plasma-sprayed ceramic castings is due to corona mechanism which can result in local erosion of the coating surface. Dielectric strength of the Al₂O₃-13%TiO₂ coating was approximately 9 ㎸/㎜ showing saturation as the thickness of the ceramic coating was increased. However, the addition of 40% TiO₂ resulted in near zero breakdown voltage. The electrical insulation properties of the coatings were improved by sealing treatment. However, the extent of improvement was different from the sealants used. |