J.M. Ramos-Fernández, M. MartÃnez-Escandell (Sp), F. Rodriguez Reinoso, University of Alicante (Spain)
Carbons materials can be used as plasma-facing components of fusion devices due to their high thermal shock resistance, absence of melting and low radiation of carbon atoms from the central plasma. In addition to these properties a high thermal conductivity, and low erosion due to energetic atoms of hydrogen and oxygen are desired. The productions of self-passivating materials using graphites doped with metallic carbides is a good method to improve the latter properties. Results with TiC carbide among other carbides indicate that this heteroatom catalyses graphitisation and increase the size of coherent height of the stack of carbon layers, thus increasing thermal conductivity of the carbon. Additionally, titanium doped graphites reduces significantly the erosion under hydrogen bombardment compared to the undoped graphites. Titanium doped graphites can be obtained mixing a self-sintering carbon precursor, such as MCMB with carbides particles, the material being more effective in erosion protection as particles size decreases and a more homogeneous material is achieved. The production of doped-carbon materials via copyrolisis of a carbon precursor with an heteroatom source soluble in the carbon precursor is a good alternative to produce doped carbons of an homogeneous nanosize particle distribution. The heteroatom precursor must be soluble in the carbon source (usually carbon or petroleum pitch) in order to achieve a good dispersion of the dopant. In our case, a mixture of a petroleum residue with an Ti-organometallic have been pyrolysed to obtain a doped self-sintering carbon material with homogenous distribution.
