Korean Institute of Surface Engineering

pISSN : 1225-8024 | eISSN : 3399-8403

공학

한국표면공학회지 (47권6호 316-322)

Structure and Thermal Conductivity of Thermal Barrier Coatings in Lanthanum/Gadolinium Zirconate System Fabricated via Suspension Plasma Spray

서스펜션 플라즈마 용사로 제조된 란타눔/가돌리늄 지르코네이트 열차폐코팅의 구조와 열전도도 특성

권창섭;이성민;오윤석;김형태;장병국;김성원;
Kwon, Chang-Sup;Lee, Sung-Min;Oh, Yoon-Suk;Kim, Hyung-Tae;Jang, Byung-Koog;Kim, Seongwon;

한국세라믹기술원 이천분원 엔지니어링세라믹팀;물질.재료연구기구 (NIMS) 선진고온재료유닛트;
Engineering Ceramic Team, Korea Institute of Ceramic Engineering and Technology;High Temperature Materials Unit, National Institute for Materials Science;

DOI : 10.5695/JKISE.2014.47.6.316

Abstract

With increase in demand for higher operating temperatures of gas turbines, extensive research efforts have been carried out to enhance the performance of thermal barrier coatings (TBCs) in the field of coating processing as well as materials. In this study, thermal barrier coatings in lanthanum/gadolinium zirconate system, which is one of the most promising candidates for replacing yttira-stabilized zirconia (YSZ) in thermal barrier coating applications, are fabricated via suspension plasma spray. Dense, $300{sim}400{mu}m$ thick coatings of fluoritephase zirconate with modest amount of segmented microstructures are obtained by using suspension plasma spray with suspensions of planetary-milled mixture between lanthanum and/or gadolinium oxide and nano zirconia. These coatings exhibit thermal conductivities of 1.6 ~ 1.7 W/mK at $1000^{circ}C$, which is relatively lower than that of YSZ.

Keywords

Thermal barrier coatings;Suspension plasma spray;Rare-earth zirconate;Phase formation;Thermal conductivity;