BORON COATINGS ON GRAPHITE FOR FUSION-REACTOR APPLICATIONS

This study is an experimental investigation of boron coatings on graphite and the preliminary determination of some of their physical and nuclear related properties. The boron was obtained by the decomposition of diborane in argon at 500 °C and 1 atm. Adhesion to the graphite (POCO AXF-5Q) was good if a slightly roughened surface was provided. The boron was pseudo-amorphous, had high purity with no observable porosity and the fractured surface showed no growth features. It was very hard (VHN25 = 2400 kg mm-2) and had good resistance to hydrogen ion erosion and to arcing. It may, therefore, be a suitable candidate for first wall and limiter coatings in toroidal magnetically confined fusion reactors. © 1979.