Progress in coating development for fusion systems D.L. Smith a, , J.-H. Park a , I. Lyublinski b , V. Evtikhin b , A. Perujo c , H. Glassbrenner d , T. Terai e , S. Zinkle f a Argonne National Laboratory, 9700 S.Cass Ave., Argonne, IL 60439, USA b Enterprise 1a Electrolitnyi proezd, Moscow 115230, Russia c Joint Research Center, 21020 Ispra, Italy d Forschungcentrum Karlsruhe, 76021 Karlsruhe, Germany e University of Tokyo, Bunkyo-ku, Tokyo 113, Japan f Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831, USA Abstract Development of effective and reliable coatings is a key to the viability of most, if not all, fusion blanket systems. The specific purpose and requirements of the coatings vary widely, depending on the blanket concept. The efforts on coating development to date have focused primarily on electrically insulating coatings for the self-cooled lithium concepts with a vanadium alloy structure, and the tritium barrier coatings for the water-cooled, Pb  /Li (WCLL) breeder concepts with ferritic steel structures. Although other coating materials are under consideration, most of the effort on the electrically insulating coatings has focused on CaO and AlN coatings on V /4Cr  /4Ti alloy structure. Most of the effort on the tritium barrier coating development is focused on Al 2 O 3 coatings formed on aluminized ferritic steels. This paper presents an overview of the status of coating development for the various fusion concepts with emphasis on the materials interaction and chemistry control issues associated with the formation, stability and performance of the coatings. # 2002 Elsevier Science B.V. All rights reserved. Keywords: Coatings; Liquid lithium blankets; Lead-lithium blankets; Oxides; Nitrides; Vanadium alloys; Ferritic steels 1. Introduction Development of effective and reliable coatings is a key to the viability of most, if not all, fusion blanket systems. It is widely recognized that coat- ings provide an attractive solution to some of the challenging materials and technology issues for fusion power applications [1  /15]. Coatings can greatly simplify the design in many cases, which could contribute to improved reliability. Coatings appear to be required for some applications, making them a feasibility issue for certain con- cepts, while coatings can enhance the performance for other applications where they become an economic issue. In order to be viable, the coatings must meet several complex requirements. A major concern regarding the use of coatings for most  Corresponding author. Tel.:  /1-630-252-4837; fax:  /1- 630-252-5287 E-mail address: dalesmith@anl.gov (D.L. Smith). Fusion Engineering and Design 61 /62 (2002) 629 /641 www.elsevier.com/locate/fusengdes 0920-3796/02/$ - see front matter # 2002 Elsevier Science B.V. All rights reserved. PII:S0920-3796(02)00291-0