Electrochemical techniques as innovative tools for fabricating divertor and blanket components in fusion technology

Abstract

Electrochemical techniques such as electroplating and electrochemical machining (ECM) are well established processes in a variety of industrial applications, such as corrosion protection coatings on steel and high electro-conductive coatings in electrical industry. The main advantages of these processes are: Good controllability of coating thicknesses, cost-effectiveness and good scalability from scientific settings to industrial scale. For applications in fusion technology, material development needs to meet unique and specific requirements, e.g. high heat-flux properties and corrosion resistance to liquid metals. Therefore, uncommon materials like tungsten, CuCrZr, RAFM-steels have to be processed for which commercially available electrochemical processes show various limitations at the moment. To overcome these limitations, selected methods were introduced in research of divertor and blanket component manufacturing leading to promising electrochemical-based processes contributing their inherent advantages to a variety of fusion applications, such as the ECX process to fabricate Al-based corrosion barriers on RAFM steels resistant to flowing Pb-15.7Li. Others are the electrodeposition of metal fillers on tungsten and CuCrZr substrates for joining applications and the machining of tungsten surfaces by ECM in first wall applications. This paper provides an overview about these processes and describes the achieved benefits of using electrochemical processing techniques for applications in fusion technology.