HEAT-FLUX EXPERIMENTS ON FIRST WALL MOCK-UPS COATED BY PLASMA-SPRAYEDB4C

The plasma compatibility of the first wall of fusion devices can be ac hieved either by using protective tiles of massive material like fibre reinforced carbon or by direct coating of the metallic wall. For ITER , the plasma spray technique provides the opportunity to coat large ar eas of the first wall with coating thicknesses of the order of 1 mm an d may allow in-situ repair of the coating. Plasma sprayed boron carbid e (B4C) is regarded as a promising candidate material because of its l ow atomic number and high melting point. In the present work, actively cooled stainless steel AISI316L bodies were coated with a copper inte rlayer and a 1.2 mm top layer of B4C. The homogeneously coated surface was 210 mm x 65 mm. The stainless steel bodies had two parallel chann els for water cooling of the mock ups. Thermomechanical testing was pe rformed in the JEBIS-facility (JAERI Electron Beam Irradiation System) . Surface heat loads of 0.5-1 MW/m(2) caused local delamination and cr acking of the coating.